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ODYSSEY LX SeriesTomographic Processing

Operator Guide

Preface ..............................................................................1-1Processing........................................................................... 1-2

SPECT Processing...........................................................2-1Overview.............................................................................. 2-1Processing a SPECT Study ..........................................................2-2

Myocardial SPECT Processing .......................................3-1Overview.............................................................................. 3-1Processing a Myocardial SPECT Study........................................3-2

Preference Details............................................................4-1Modify Preferences .......................................................................4-2

Create a New Preference..............................................................4-5

Program Preferences ....................................................................4-7

PET Rebinning.........................................................................4-8

PET Uniform Attenuation Correction ...............................4-8SPECT Motion Correction .....................................................4-10

2D Prefilter.............................................................................4-11

Transverse Reconstruction....................................................4-16

3D Postfilter ...................................................................4-19Overlay ..................................................................................4-26

Table of Contents

ODYSSEY Tomographic ProcessingTable of Contents

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SPECT Uniform Attenuation Correction................................ 4-27

UNITE/3D Processing ........................................................... 4-29

Oblique Reformat .................................................................. 4-30

Processing Details........................................................... 5-1PET Rebinning ............................................................................. 5-2

PET Rebinning Control Panel ................................................. 5-3

Options Drop-Down Menu Selections ..................................... 5-4

Status Area ............................................................................. 5-8

File Selection Menu .........................................................5-8General Program Selections ...........................................5-8Rebinning a Study................................................................... 5-9

SPECT Motion Correction .......................................................... 5-11

Motion Correction Control Panel ...................................5-12Dynamic Help and Instruction Area ...............................5-12Motion Correction Controls ............................................5-13General Program Selections ................................................. 5-14

Motion Correcting a Study..................................................... 5-15

2D Prefilter.................................................................................. 5-20

2D Prefilter Control Panel ..............................................5-21Filter Selections..................................................................... 5-22

Status Area....................................................................5-22Filter Control(s) ..............................................................5-23General Program Selections .........................................5-23Prefiltering a Study................................................................ 5-24

Gallery Mode......................................................................... 5-26

Transverse Reconstruction......................................................... 5-27

Reconstruction Control Panel ........................................5-27Options Drop-Down Menu Selections ...........................5-28Status Area....................................................................5-31


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General Program Selections .........................................5-31File Selection Menu .......................................................5-31Reconstructing a Study..........................................................5-32

3D Postfilter.................................................................................5-36

Postfilter Control Panel ..................................................5-37Filter Selections .....................................................................5-38

Status Area....................................................................5-38Filter Control(s) ......................................................................5-39

File Parameters .............................................................5-39General Program Selections..................................................5-40

Postfiltering a Study...............................................................5-41

Gallery Mode .........................................................................5-45

Overlay........................................................................................5-46

Overlay Display Control Panel.......................................5-47Overlay Display Main Menu Functions ..................................5-48

SPECT Uniform Attenuation Correction......................................5-49

Uniform Attenuation Correction Control Panel ..............5-50File Information ......................................................................5-51

Status Area....................................................................5-51Ellipse Method Control ..................................................5-51General Program Selections..................................................5-52

Image Rotation and Control...................................................5-53

Uniform Attenuation Correcting a Study ................................5-54

UNITE/3D Processing .................................................................5-59

Multi-Volume Knitting Control Panel ..............................5-60Status Area....................................................................5-60General Program Selections .........................................5-61Multi-Volume Knitting.....................................................5-62

Oblique Reformat ........................................................................5-63


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Oblique Reformat Control Panel....................................5-64Options Drop-Down Menu Selections ................................... 5-65

Status Area ........................................................................... 5-68

General Program Selections .........................................5-68File Selection Menu .......................................................5-68Oblique Reformatting ............................................................ 5-69

Tomographic Display.................................................................. 5-73

Tomographic Display Menu...........................................5-73Tomographic Display Menu Selections ...................................... 5-74

ODYSSEY Tomographic Processing

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Tomographic Processing uses one sequence to complete the processing steps of multiple programs. The process executes each program according to specific parameters, which are deter-mined through a preferences editor.

The Tomographic Processing application adjusts the prefer-ences that are available, based on the data selected. For exam-ple, if a bone study patient is on the Workbench and you select to run a PET process, the General SPECT Preferences Selector appears because of the bone SPECT data.

SPECT Processing and Cardiac Processing are factory applica-tions. PET Processing, BEACON-P, and BEACON-S are optional processing applications. To process PET and BEACON studies, the appropriate software enable keys must be installed.

Preface

NoteRefer BEACON Option and γPET Option with BEACON for complete information on processing BEACON, PET, and PET with BEACON studies.

ODYSSEY Tomographic ProcessingPreface

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ProcessingOnly one patient can be selected from the Clinical Index when running a Tomographic process. The processing system recog-nizes the files that are on the Workbench and decides what type of process to use for those files. As the process begins, if more than one patient file is available, the Pick Files window appears. You may select up to 10 files to run through the process. Select the patient raw data (R) or events (E) files that are compatible with the process.

Each program that is part of the Tomographic process is consid-ered a “block.” These blocks contain numerous steps that must run before the process completes that block.

If multiple files have been selected for a patient, the files are pro-cessed in sequential, yet parallel order. This means that each of the files runs through the entire process - one block at a time, one file at a time. The process completes each block, running each file through that program. The following image shows an example of three files running through part of a SPECT Tomo-graphic Process.


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Tomographic Processing runs similarly for each process, regard-less of what type of files are part of the patient study.

a. Select what type of process to run: SPECT, myocardial SPECT, PET, or BEACON.

The system opens the Tomographic Processing Window and the Clinical Index (if no patient is on the Workbench).

b. Select a patient from the Clinical Index.c. The system selects R or E files, if present.

The process begins.

The files run through each block of the Tomographic process according to the preferences that were set for each program.

Depending on how many files and what type of files are selected, you may see different blocks of the process repeat. A study may have gated vs. ungated files, Uniform Attenuation Correction and Non-Uniform Attenuation Correction performed on the files, or no Attenuation Correction performed at all. For example, in a γPET with BEACON process, the files run through Transverse Reconstruction three times.

If Non-Uniform Attenuation Correction is set as a preference to run during the process, the following criteria must be met:

BEACON files must be acquired.BEACON files must be available to be processed.The appropriate BEACON software enable key must be installed.

NoteBEACON is an optional hardware and software package. Refer to BEACON Option or γPET Option with BEACON.


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The Tomographic Processing menu consists of program blocks. As the process advances, each block that applies to this pro-cess will be highlighted. A status arrow appears next to each block to indicate the progression. You cannot select the individ-ual blocks while the process is running. After the process is complete, you can return to a specific point in the process by selecting a highlighted block from the menu. The program that is selected to run again will appear in interactive mode. You can then modify the areas of that program which need readjusting. The process will run the subsequent blocks as they were set to run in the preferences.


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A block in the process will only run if:the product is installed on the system,the block has been selected as part of the preferences,and the block applies to this process.

Patient Selection is the first block. After the patient files have been selected, one of two blocks will run. SPECT studies begin with SPECT Motion Correction, while PET studies rebin E (event) files. The process will automatically run through each block that applies to the process.

You can manually abort processing at the completion of any block. A Stop Processing button is available during the entire process:

When you click on the Stop Processing button, the following dialog is displayed:

Click OK to confirm. Processing will stop after the current block in the process is completed.

NoteRefer to Preference Details for information on running the process with automatic or interactive program settings.


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Tomographic processing can be done on raw data files only. Files that have been modified using Image Algebra, or that have been corrected for orientation, are not available for processing and are not displayed in the file selection list (during the first block of processing).

However, using the Import Modification Utility, these files can be modified further so that they appear as raw data available for processing. Use the following procedure:

a. From the Workbench File menu, select Import Modification. The Imported File Modify menu is displayed:

b. Click on Select Files to display the Clinical Index.c. From the Clinical Index, select files for processing and

click on Done. A PIXIE Poster displays the currently selected file.


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d. If necessary, use the left and right arrow buttons on the Imported File Modify menu to scroll through selected files.

e. Select Modify Current File. The Imported File Category Menu is displayed:

f. Select Tomographic File Modification... The Tomographic Processing Menu is displayed.

g. Select Allow Tomographic Processing. The system displays a message confirming file conversion.

h. Select OK. i. Select Done from the Import File Modify Menu. The

modified file will display in the files selection list.


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OverviewThis chapter shows how to process a Bone SPECT study as an example of a SPECT Tomographic process.

Select Bone SPECT and Brain SPECT from the SPECT Processing menu to process Bone and Brain SPECT studies. Select General SPECT from the SPECT Processing menu to process Gallium, Indium, Liver, and BEACON-SPECT studies.

SPECT Processing

NoteYou may want to create preference sets for other studies that are performed in your department. Refer to Preference Details on how to create new preferences.

ODYSSEY Tomographic ProcessingSPECT Processing

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Processing a SPECT StudyThe following process uses a Bone SPECT study as an example for SPECT Tomographic processing. The Bone SPECT processing factory preference is set to default preferences.

Each program in the following process is linked to a descriptive layout of that program in the Processing Details section. For more information about using the programs interactively during the process, refer to the program in the Processing Details section.

NoteTo modify SPECT preferences before running the process, refer to Preferences Details.


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Start the Program

1. Start the process. Workbench:Tomo-Processing → SPECT Processing → Bone SPECT

Select a Patient

2. Select a SPECT patient.

If you have not selected a patient, select one from the Clinical Index.

The Clinical Index appears if there is no patient on the Workbench.

If there is a patient on the Workbench Selected File List, the process begins.

The system verifies that the patient has the appropriate file types.

Procedure DetailsProcessing a SPECT Study

NoteIf there is a patient on the Workbench, the process will automatically start. Before selecting to start the process, verify this is the correct patient.

NoteIf more than one file is available for the patient, the Pick Files control panel will appear. You may select up to 10 patient files. Select Cancel to pick a new patient.


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Perform Motion Correction

SPECT Motion Correction begins: SPECT Motion Correction is an interac-tive program. Refer to SPECT Motion Correction in the Processing Details sec-tion for details on how to motion correct the images.

The Image Window and control panel are displayed. A cine is shown in the upper-left corner of the Image Window with horizontal and vertical sinograms beneath the cine.

3. Correct the images for patient motion.

4. Save the corrected slices.


NoteIf Motion Correction is not needed, select Done and continue with the next block of the process.


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Reconstruct Study

Transverse Reconstruction begins:

The Transverse Reconstruction windows are displayed. Two planar reference views appear in the Image Window.


NoteTransverse Reconstruction is an automatic process. Refer to Transverse Reconstruction in the Processing Details section for information on manually reconstructing the images.

NoteIf BEACON files have been acquired and the BEACONS software enable key has been installed, Non-Uniform Attenuation Correction will begin. Refer to the BEACON Option Operator Guide.


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Postfilter Study

3D Postfilter begins:

You will not be able to view postfiltering in the Automatic mode. Postfiltering runs in the background of the system. The type of filter used during postfiltering is selected in the program preferences.


NotePostfiltering is an automatic process. Refer to 3D Postfilter in the Processing Details section for information on manually filtering the images.


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Reformat Study

Oblique Reformat begins:

Slice thickness and the image ID for transverse, sagittal, and coronal views are set.


NoteOblique Reformat is an automatic process. Refer to Oblique Reformat in the Processing Details section for information on manually reformatting the images.


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Display and Analyze StudyThe Tomographic Display window opens:

If there are multiple sets, select the appropriate processed sets to be dis-played from the processed set menu. Select them in the order they are to be displayed.



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5. Store the screen as a lightbox or print screen, if desired.

6. To exit Tomo Display:Select Done with Tomographic Display.Select Done and Add This to the Review List to exit and add the patient study to the Study Review.

The main Tomographic Processing menu reappears.


NoteRefer to Tomographic Display in the Processing Details section for further information.


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Review

Review the image quality of the pro-cessed data. If selected processing steps need to be performed again with new parameters, you can go back to the various program blocks to make the nec-essary changes.

7. If you are unsatisfied with one of the processing parameters, select the program block from the Tomographic Processing menu to make the necessary changes.

The process opens the program in Interactive Mode.

8. Reprocess the files as required.

9. Select Done from the program control panel.

The tomographic process runs the rest of the program blocks, retaining the parameters that were set for the initial process.

Exit Tomographic Processing10. Select Tomo Processing

Done to exit the program.


NoteYou can return to as many program blocks as necessary to complete the process.


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OverviewMyocardial SPECT studies, containing both rest and stress protocols, are included under the Cardiac Processing menu on the Workbench. After setting the preferences in the Preference Editor, select the study type from the Cardiac Processing menu to run the myocardial SPECT Tomographic process. You may want to create preference sets for other studies that are performed in your department.

Myocardial SPECT Processing

ODYSSEY Tomographic ProcessingMyocardial SPECT Processing

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Processing a Myocardial SPECT StudyThe following process uses a One-Day MIBI study as an example of a myocardial SPECT study. The One-Day MIBI processing factory preference is set to default preferences.

If both a rest and a stress file were selected from the patient study, both study files run together, yet sequentially, through each applicable block in the process. If a file is gated, Image Algebra converts the file to ungated before running the file through the process.

Each program in the following process is linked to a descriptive layout of that program in the Processing Details section. For more information about using the programs interactively during the process, refer to the program in the Processing Details section.

NoteFor optimal results in an automatic cardiac study process, select the better quality cardiac study first.

NoteTo modify myocardial SPECT preferences before running the process, refer to Preferences Details.


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Start the Program

1. Start the process. Workbench:Tomo-Processing → Cardiac Processing → One-Day MIBI

Select a Patient

2. Select a myocardial SPECT patient.

If you have not selected a patient, select one from the Clinical Index.

If there is a patient on the Workbench Selected File list, the process begins.

The system verifies that the patient has the appropriate file types.

Start Processing the Study

3. Select a rest and a stress study from the Pick Files control panel. Select Cancel to pick a new patient.

Both rest and stress files will run through the process. If one of the files is gated, Image Algebra will convert the file to ungated.

Procedure DetailsProcessing a Myocardial SPECT Study

NoteIf there is a patient on the Workbench, the process will automatically start. Before selecting to start the process, verify this is the correct patient.


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SPECT Motion Correction begins:

4. Correct the images for patient motion.

5. Save the corrected slices.


NoteSPECT Motion Correction is an interactive program. Refer to SPECT Motion Correction in the Processing Details section for information on how to motion correct the images.

NoteBoth ungated files, along with the gated file, will run through the rest of the blocks in the process.

NoteIf Motion Correction is not needed, select Done and continue with the next block of the process.


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Reconstruct Study

Transverse Reconstruction begins:


Adjust Reconstruction Diameter

6. Use the resizing grip (on either reference frame) to increase the reconstruction diameter for a patient with a large heart, if necessary.

The reconstruction diameter cannot be greater than the original data values. If you change the diameter outside the original data range, the maximum possi-ble value is used. A warning message appears indicating this condition. Note that for this step, you can use either resizing grip.


NoteRefer to Transverse Reconstruction in the Processing Details section for further information on reconstructing the images.

NoteTo return Recon Diameter to the default value, press Restart.


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Center Region In Reference Rectangles

7. Move the positioning grip in the “Offset 1" (left) reference rectangle to center the region of interest in the rectangle.

This step involves moving both the left and the right reference rectangles so the region of interest is centered in each rectangle. Note that for this step, you need to center both reference images individually.

Center Region In Reference Rectangles8. Move the positioning grip in the

“Offset 2" (right) reference rectangle to center the region of interest in the rectangle.

A reference slice appears under the rect-angles.


NoteTo return Offset 1 or Offset 2 to default values, press [F1] and then [ENTER] in the appropriate text entry field. Change Parameters must be open to adjust default values.


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Determine Region of Interest Center Slice9. Drag the diamond grab box to

adjust the number of slices in the region of interest.

10. Drag the center line to determine the placement of the center slice in the region of interest, if necessary.

11. Review the sample reconstructed slice.

Reconstruct Slices

12. Select Reconstruct.

13. Select Done to exit Transverse Reconstruction.


NoteRight-click to clear the sample slices displayed in the Image Window.

NoteIf BEACON files have been acquired and the BEACONS software enable key has been installed, Non-Uniform Attenuation Correction will begin. Refer to BEACON Option.


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Postfilter Study

3D Postfilter begins: You will not be able to view postfiltering in the Automatic mode. Postfiltering runs in the background of the system. The type of filter used during postfiltering is selected in the program preferences.

Reformat StudyOblique Reformat begins: Reformat the study into short axis, hori-

zontal long axis, and vertical long axis views.


NotePostfiltering is an automatic process. Refer to 3D Postfilter in the Processing Details section for information on manually filtering the images.

NoteRefer to Oblique Reformat in the Processing Details section for further information on reformatting images.

NoteTo modify or verify the selected angles during the study process, set the Oblique Reformat preference to interactive.


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Select Work Image For A View

14. Left-click on one of the images to select the work image or use the valuator controls for Image.

The work images are displayed in the work area of the Image Window. The axis or slice bars are overlaid on each view.

Set Reformatting Parameters

If you know the exact value, enter a value for X, Y, or Z in the reformatting parameters section of the control panel for that view. Change Parameters must be open to adjust values.

15. Set the axis for each view:

a Left-click anywhere on the center bar, except for the diamond and circular grab boxes, and drag.

b Release the mouse button when the axis is adjusted.


NoteYou can set parameters and reformat either each view one at a time or all three views at one time.

NoteIf you cannot see the heart, select Zero Angles and Centers from the Oblique Reformat Options menu.

NoteWhen a new value is entered for X, the change appears in the Y and Z views. Similarly, a change in Y appears in the X and Z views and a change in Z appears in the X and Y views.


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16. Set the angle of the axis for each view using one of the following methods:

Place the pointer on the circular handle, hold down the left mouse button while dragging the mouse, and release the mouse button when the angle is set.

OR

Enter a value for Angle in the reformatting parameters section of control panel for that view.

If the images are displayed at an angle, you can correct the reformatted slices.


NoteIf you desire assistance in setting cardiac angles, enable the cardiac angles tutorial by clicking left on the How to menubar option and then choosing the tutorial option or you can enable the tutorial to always activate with cardiac studies by setting the default option in the Oblique Configuration control panel.

NoteWhen processing two studies simultaneously (such as a stress and a rest), the angles used for the first study will be used for the second study.


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17. Select the slice limits for each view:

a Left-click on the diamond grab box for one of the views and drag.

b Release the mouse button when in position.

18. Verify the orientation selected during the auto-orient function.

The orientation angle for each view is located in the Image Window.

Reformat Slices and Exit

19. Left-click on Reformat all views to reformat slices for all three views.

The new oblique (O) files are placed in the Workbench Selected File List and in the patient directory.


NoteIf HLA is configured for non-standard orientation, you cannot perform oblique reformatting in Tomographic Processing; you must manually perform oblique reformatting on the transverse slices.


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Display and Analyze the StudyThe Tomographic Display window opens:

If there are multiple sets, select the appropriate processed sets to be dis-played from the processed set menu. Select them in the order they are to be displayed.



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20. Store the screen as a lightbox or print screen, if desired.

21. To exit Tomo Display:Select Done with Tomographic Display.Select Done and Add This to the Review List to exit and add the patient study to the Study Review.

The main Tomographic Processing menu reappears.


NoteRefer to Tomographic Display in the Processing Details section for further information.


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Review

Review the image quality of the pro-cessed data. If selected processing steps need to be performed again with new parameters, you can go back to the various program blocks to make the nec-essary changes.

22. If you are unsatisfied with one of the processing parameters, select the program block from the Tomographic Processing menu to make the necessary changes.

The process opens the program in Interactive Mode.

23. Reprocess the files as required.

24. Select Done from the program control panel.

The tomographic process runs the rest of the program blocks, retaining the parameters that were set for the initial process.

Exit Tomographic Processing

25. Select Tomo Processing Done to exit the program.


NoteYou can return to as many program blocks as necessary to complete the process.


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Preferences are the parameters that determine how each program during a Tomographic Process will run. You can edit preferences before running a process. Select the processing type preferences menu from the Workbench to set the parameters:

SPECT:Tomo-Processing → SPECT Processing → SPECT Preferences Myocardial SPECT:Tomo-Processing → Cardiac Processing → Cardiac Preferences PET:Tomo-Processing → PET Processing → PET Preferences

Even if a preference has been selected, the following criteria must be met before that preference will run as part of the process:

Optional products must be installed. The program must apply to the process.

Preference Details

NoteSet BEACON SPECT and BEACON PET preferences from the General SPECT, Myocardial SPECT, and PET preference editors.

ODYSSEY Tomographic ProcessingPreference Details

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Modify PreferencesBefore selecting a process from the Workbench, verify the process will run according to your specifications.

Select a Site or Factory Preference and edit the parameters for each program. The following example is to modify preferences for a Bone SPECT process.

Select Preference

1. Open the Preferences Selector.

Workbench:Tomo-Processing → SPECT Processing → SPECT Preferences

2. Select Bone SPECT Processing from the Factory Preferences list.

Procedure DetailsModifying Processing Preferences


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Set Preferences

3. Select Modify to adjust the preferences.

The Processing Preferences editor appears.

4. Select the block of the process to modify.



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5. Set the parameters for the block.

6. Select Update to save modifications.

The Preferences Selector control panel reappears.

7. Select Done to exit.


NoteUse Factory Defaults will set all preferences for the process to default preferences.


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Create a New PreferenceIf you want to create a new preference selection for a process, select New.

Select Preference

1. Open the Preferences Selector.

Workbench:Tomo-Processing → SPECT Processing → SPECT Preferences

2. Select a preference from the Factory Preferences or Site Preferences list.

3. Select New. An edit box appears.

Procedure DetailsCreating New Processing Preferences


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Name Process

4. Enter a description for the new set of preferences that you want to create.

5. Select OK. The Processing Preferences control panel appears.

6. Select new parameters for the new processing preference.

7. Select Update to save all new preferences.

The Preferences Selector control panel reappears with the new processing pref-erences listed in the Site Preferences list.

8. Select Done to exit.

Procedure DetailsCreating New Processing Preferences


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Program PreferencesThe following program preferences are listed in this chapter:

If You Want To: Go To:review rebinning PET Rebinningreview PET Attenuation Correction PET Uniform Attenuation Correctionreview motion correction SPECT Motion Correctionreview prefiltering 2D Prefilterreview reconstruction Transverse Reconstructionreview postfiltering 3D Postfilterreview overlay display Overlayreview Attenuation Correction SPECT Uniform Attenuation Correctionreview knitting files UNITE/3D Processingreview oblique reformat Oblique Reformat

NotePreference defaults will differ based upon the type of process being configured.


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PET Rebinning PET Rebinning is an option that only comes with PET software. It is used to convert E (events) files into R (projection data) files so that the system can process the files.

PET Uniform Attenuation CorrectionPET Uniform Attenuation Correction (UAC) produces a new attenuation corrected Raw Data (R) file to be used during processing.

NoteRebinning will only run during a PET process. Refer to PET Rebinning in Processing Details.


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Field Selection Available Preferences DescriptionRebin

Rebin Type: AutomaticInteractive

Select Rebinning to run automatically or interactively.

Rebin Matrix Size:

64128256

Specify the final output matrix size for projections.

Uniform ACDo Uniform AC Yes

NoSelect whether or not to perform uniform attenuation correction.

Method: FileGroupSlice

Select how the files will be rebinned:

File - one fileGroup - a group of files (2 or 3)Slice - a slice of the file

Group Size: 23

Select to group 2 or 3 of the files together.

Zero Mask OnOff

Eliminate data outside the defined ellipse.

Edge Threshold (1% - 50%)

5 Adjust the edge detection threshold (the percentage of the maximum pixel count in the image at which the counts at the edge of the image are detected) to modify the ellipse algorithm.

NoteFor further information about PET Rebinning and PET Uniform Attenuation Correction, refer to γPET Option with BEACON Operator Guide.


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SPECT Motion CorrectionSPECT Motion Correction corrects for any patient motion that occurred during acquisition. This program can only be used with SPECT raw data files. Motion correction is applied to the raw data before filtering, reconstructing, and reformatting. Before the next program in the process can begin, you must examine the image and verify if there was or there was not any patient movement. If there was patient motion, you must correct the image.

Field Selection Available Preferences DescriptionDo Motion Correction?

YesNo

Select to run motion correction.

Correction Axis: YX and Y

Select Y for vertical as most patients, if they change position, will move vertically.

NoteMotion Correction will only process during a SPECT study process and cannot be set to run automatically.

NoteFor further information on SPECT Motion Correction, refer to Reviewing and Analyzing the Study.


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2D PrefilterThe Prefilter program is used to remove unwanted effects of high-frequency noise from raw acquisition data and provide contrast enhancement. Prefilter accepts and filters data from any studies with the exception of Whole Body studies. The application of a noise reduction filter before reconstruction gives you the ability to adjust and see the effect on the image without having to reconstruct the image. It is advisable to only use one type of filter per process - whether Prefilter or Postfilter.

Interactive GalleryThe choice to use Interactive Gallery generates a selection of filters.

The Interactive Gallery appears if Interactive Gallery? has been set to Yes, AND:

Prefilter Operation is selected to Interactive.

OR Prefilter has been reselected to run after the process is complete.

Three to thirteen images appear, including the last selected image from the process. Select the best image from the new images.

NoteOver-filtering is not advised as image detail may be obscured.

NotePrefiltering should only be used on Low Count Tomo studies which have less than 6 million counts. Check the console window for the number of events in the file. Prefiltering can be used for SPECT and PET studies.


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Field Selection Available Preferences DescriptionPrefilter

Do Prefilter? YesNo

Select to run prefiltering.

Prefilter Operation: AutomaticInteractive

Select to run prefiltering automatically or interactively.

3D Prefilter GalleryInteractive Gallery?

YesNo

Select to use gallery selection of filters for interactive filtering.

Number of Frames (3-13):

5 Select how many frames will appear when using the interactive gallery.

Increment: 0.03Increment is applied to the following values:

Low Pass: CutoffMetz: XWeiner: Mult

For example, if 0.03 is the increment and the Cutoff value is 0.30, the image filter values will be 0.24, 0.27, 0.30, 0.33, and 0.36.

Select how far apart the filter change should be for each of the images. The value is based on 5 cm increments.

Plain Filter TypeFilter Type: Low Pass

MetzWiener

Use Low Pass filtering for most tomographic processing studies.

Order 4.0 Control slope to optimize image quality.

Cutoff 0.30 Control frequency to optimize image quality.

X 1.0 Use only for Metz filter.Mult: - Use only for Weiner filter.


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NoteThe following parameters only appear in the Myocardial SPECT preferences.

Field Selection Available Preferences DescriptionPlain Filter Type

StressFilter Type: Low Pass

MetzWiener





RestFilter Type: Low Pass

MetzWiener





Gated Filter TypeStress

Filter Type: Low PassMetzWiener




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MetzWiener





Field Selection Available Preferences Description

NoteFor further information on Prefiltering, refer to Reviewing and Analyzing the Study.


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Modulation Transfer Function FilesThe following isotope and collimator combinations have Modulation Transfer Function (MTF) files defined for them and are supported by Metz and Weiner filters. If you attempt to apply a Metz or Weiner filter on any other type of data sets, an MTF error will appear.

NoteLow Pass filtering is recommended for studies that do not have MTFs defined for them.

Collimator IsotopeLow Energy Ultra High Resolution Parallel Beam Tc-99mLow Energy Ultra High Resolution Parallel Beam Tl-201Low Energy Ultra High Resolution Fan Beam Tc-99mLow Energy Ultra High Resolution Fan Beam Tl-201Low Energy Ultra High Resolution Asymmetric Fan Beam

Tc-99m

Low Energy Ultra High Resolution Asymmetric Fan Beam

Tl-201

Medium Energy Gap Parallel Beam Ga-67Medium Energy High Resolution Parallel Beam Ga-67

NoteThe MTF files exist for both scatter and non-scatter. They also are used for distances of 5, 10, 15, 20, and 25 cm increments.


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Transverse Reconstruction Transverse Reconstruction generates transverse slices from raw acquisition data using Filtered Backprojection or Iterative Reconstruction.

Field Selection Available Preferences DescriptionGeneral Reconstruction

Reconstruction Type:

AutomaticInteractive (Myocardial)

Select to run reconstruction automatically or interactively.

Matrix Size: Default64128256

Sets the matrix size in pixels.

Save Attenuation Map?

YesNo

NOTE: This is for BEACON studies only.

Select to save the attenuation map. Overlay displays the emission file fused over the transmission image.

Diameter (1%-100%):

100 Select the actual reconstruction diameter in percent of FOV.

Center Slice (1%-100%):

50NOTE: 50 = center of slice range

Adjust the center percent FOV of the set of reconstructed images. This distance is measured from the top of the FOV.

Number of Slices (1%-100%):

69 (20 for Myocardial) Adjust the percent of the FOV to create a slice range around the center slice.

Slice Thickness (1-20 pixels):

1For example, if the range is 48 slices, and the slice thickness is 1 (default), than 48 slices will be present.

Adjust the thickness of the reconstructed slice in pixels in the percent of FOV.


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Plain DataAlgorithm: FBP

OSMLEMMLEM

NOTE: OSMLEM and MLEM are only available when you have the Iterative software enable key.

Select the reconstruction type and the range of projection data to use.

FBP - Filtered BackprojectionOSMLEM - Iterative Reconstruction using ordered subsetsMLEM - Iterative Reconstruction using projection data

Iterations (1-99): 4 Select the number of repetitions to perform during iterative reconstruction.

Data with Non-UniformAttenuation Correction

Algorithm: OSMLEMMLEM



OSMLEM - Iterative Reconstruction using ordered subsetsMLEM - Iterative Reconstruction using projection data



NoteNon-Uniform Attenuation Correction is only used during processing if the BEACONS and/or BEACONP software enable keys are installed. Refer to γPET Option with BEACON or BEACON Option Operator's Guide for further information on Non-Uniform Attenuation Correction.


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Field Selection Available Preferences DescriptionPlain Gated Data

Algorithm: FBPOSMLEMMLEM



FBP - Filtered BackprojectionOSMLEM - Iterative Reconstruction using ordered subsetsMLEM - Iterative Reconstruction using projection data


Gated Data with Non-UniformAttenuation Correction

Do Att. Corr. for Gated?

YesNo

Select the number of repetitions to perform during iterative reconstruction.

Algorithm: OSMLEMMLEM



OSMLEM - Iterative Reconstruction using ordered subsetsMLEM - Iterative Reconstruction using projection data



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3D PostfilterThe 3D Postfilter program removes unwanted effects of high frequency noise, by applying a three dimensional filter to reconstructed images. The application of a noise reduction filter gives you the ability to adjust and see the effect on a reconstructed image. Avoid over-filtering images as detail may be lost.

This option looks at the preferences that have been set up for the process and uses these specific filters for the process. There can be from 1 to 30 filters configured. Most operators choose to select up to 6 filters, as selecting 30 filters will take an excessive amount of time. Using 6 filters will give an image that is most compatible to the process.

In Prefiltering, a two dimensional filtering is applied to raw data. By applying the filter after reconstruction, you are able to see the results of the filter immediately and make any necessary adjustments. Postfilter also makes it possible to filter studies that have been acquired using fanbeam collimators.

Interactive GalleryThe choice to use Interactive Gallery generates a selection of filters.

The Interactive Gallery appears if Interactive Gallery? has been set to Yes, AND:

Postfilter Operation is selected to Interactive.

OR Postfilter has been reselected to run after the process is complete.

Three to thirteen images appear, including the last selected image from the process. Select the best image from the new images.


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Field Selection Available Preferences Description3D Postfilter

Do Postfilter? YesNo

Select to perform postfiltering on the images.

Postfilter Operation AutomaticInteractive

Select to run postfilter automatically or interactively.

3D Postfilter GalleryInteractive Gallery?

YesNo

Select to use gallery selection of filters for interactive filtering.

Number of Frames (3-13):

5 Select how many frames will appear when using the interactive gallery.

Increment: 0.03Increment is applied to the following values:

Low Pass: CutoffMetz: XWeiner: Mult

For example, if 0.03 is the increment and the Cutoff value is 0.30, the image filter values will be 0.24, 0.27, 0.30, 0.33, and 0.36.

Select how far apart the filter change should be for each of the images. The value is based on 5 cm increments.

Plain Filter TypeFilter Type Low Pass

MetzWiener




X 1.0 Use only with Metz filter.Mult: - Use only with Weiner filter.


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NUAC Filter Type Non-Uniform Attenuation Correction for Non-gated data

Filter Type Low PassMetzWiener




X 1.0 Use only with Metz filter.Mult: - Use only with Weiner filter.



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Field Selection Available Preferences DescriptionPlain Filter TypeStress







MetzWiener





NUAC Filter TypeStress





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MetzWiener





Gated Filter TypeStress







MetzWiener





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NUAC Gated Filter TypeStress







MetzWiener






NoteFor further information on Postfiltering, refer to Reviewing and Analyzing the Study.


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Modulation Transfer Function FilesThe following isotope and collimator combinations have Modulation Transfer Function (MTF) files defined for them and are supported by Metz and Weiner filters. If you attempt to apply a Metz or Weiner filter on any other type of data sets, an MTF error will appear.

NoteLow Pass filtering is recommended for studies that do not have MTFs defined for them.

Collimator IsotopeLow Energy Ultra High Resolution Parallel Beam Tc-99mLow Energy Ultra High Resolution Parallel Beam Tl-201Low Energy Ultra High Resolution Fan Beam Tc-99mLow Energy Ultra High Resolution Fan Beam Tl-201Low Energy Ultra High Resolution Asymmetric Fan Beam

Tc-99m

Low Energy Ultra High Resolution Asymmetric Fan Beam

Tl-201

Medium Energy Gap Parallel Beam Ga-67Medium Energy High Resolution Parallel Beam Ga-67

NoteThe MTF files exist for both scatter and non-scatter. They also are used for distances of 5, 10, 15, 20, and 25 cm increments.


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OverlayOverlay is only used during BEACON studies. It displays the transverse non-attenuation corrected slices from the primaryenergy window and the transverse attenuation map file simultaneously. Overlay is used to evaluate whether the attenuation map is satisfactory, and also to check for patient motion between the emission and transmission scans.

NoteFor BEACON studies, select Yes for Do Overlay?.

Field Selection Available Preferences DescriptionOverlay

Do Overlay YesNo

Select to run the overlay option. Overlay displays the emission file fused over the transmission image.

Image Display Size:

64128192256320384512

Select what size the images will appear when displayed with the overlay view.

Image Zoom (1.0-5.0):

1.5 Select how much the zoom will increase the image view.

NoteFor more information on how Overlay displays images during a BEACON process, refer to γPET Option with BEACON.


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SPECT Uniform Attenuation CorrectionWhen gamma ray photons pass through a patient, they travel through both the organ of interest and the surrounding body tissues. As a result of the differences in tissue type and travel distances, those photons emitted from deeper within the body have a greater likelihood of being absorbed or scattered than those emitted closer to the body's exterior. This differential loss of photons due to passing through other tissues is referred to as attenuation.

NoteSPECT Uniform Attenuation Correction produces an Image (T) file whereas PET Uniform Attenuation Correction produces a Raw Data (R) file.


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Field Selection Available Preferences DescriptionSPECT Attenuation Correction

Do Attenuation Correction?

YesNo

Select to perform uniform attenuation correction.

Method: FileGroupSlice

Select how the files will be corrected:

File - one fileGroup - a group of files (2 or 3)Slice - a slice of the file

Group Size: 23

Select to group 2 or 3 of the files together.

Zero Mask: YesNo

Eliminate data outside the defined ellipse.

Threshold(1%-50%):

5 Adjust the threshold to modify the ellipse algorithm. The threshold is the % of the maximum pixel count in the image at which the counts at the edge of the image are detected.


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UNITE/3D ProcessingThe Multi-Volume Knitting option enables “stitching” of two to five image volumes. Multiple volumes can be knit in three dimensions and up to five times. You can use one of three knitting options: Automatic, Sequential, or Simultaneous.

NoteThe Unite software enable key must be installed to knit multiple volumes during a Tomographic process.

Field Selection Available Preferences DescriptionUNITE Processing

Do Volume Knitting?

YesNo (Myocardial)

Select to run volume knitting on the images.

MPR ProcessingDo Max Pixel Raytrace?

YesNo

Select to run Max Pixel Raytrace and view the images in a three dimensional view.

3D Surface ProcessingDo 3D Surface? Yes

NoSelect to render and view surfaces in 3D from any direction. Surfaces are defined by designated thresholds.

NoteFor further information on the Multi-Volume Knitting processing, refer to Multi-Volume Knitting.


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Oblique ReformatThe purpose of this program is to reformat transverse images along any arbitrary axis from an attenuation corrected, non-gated transverse (T) file, although previously reconstructed files are also accepted.

For cardiac studies, the program creates oblique short axis, horizontal long axis, and vertical long axis slices. For non-cardiac studies, the program creates transverse, coronal, and sagittal slices. Although the same types of slices are created for all non-cardiac studies, there are significant size differences between Whole Body SPECT and other studies, therefore it is a separate category of image files.

The following message appears if the Oblique Reformat preference is set to automatic and the auto-orient function fails:

Click Proceed to manually set the angle and slice settings.

If your cardiac study population requires a high percentage of manual orientation adjustment, you may want to change the preference for Oblique Reformat to interactive to proceed directly into the manual orientation and avoid this prompt.


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Field Selection Available Preferences DescriptionOblique Reformat

Oblique Reformat Type:

AutomaticInteractive (Myocardial)

Select to run oblique reformat automatically or interactively.

Slice Thickness (1-10):

1 Adjust the thickness of the reformatted slice in pixels.

Output Matrix Size: Default (SPECT)64 (Myocardial)128256

Set the matrix size of the reformatted image.

Pixel Size: Default (SPECT)Custom (Myocardial = 6.4)

Select to have the reformatted image size set to either default or a custom size (1-10 mm).

NoteFor further information about Oblique Reformat, refer to Reviewing and Analyzing the Study.


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In this chapter, you will learn the processing details concerning all aspects of each program in a tomographic processing study.

The following programs are described as though their preferences are set to run interactively with control panels.

Processing Details

If You Want To: Go To:review rebinning PET Rebinningreview motion correction SPECT Motion Correctionreview prefiltering 2D Prefilterreview reconstruction Transverse Reconstructionreview postfiltering 3D Postfilterreview overlay display Overlayreview Attenuation Correction SPECT Uniform Attenuation Correctionreview knitting files UNITE/3D Processingreview oblique reformat Oblique Reformatreview displaying a Tomographic study

Tomographic Display

ODYSSEY Tomographic ProcessingProcessing Details

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PET RebinningPET Rebinning is a specific option of a PET or PET with BEACON process. Unlike SPECT studies, PET studies are collected in Raw List mode. The information is saved in an E (events) file.

You cannot apply Filtered Backprojection or Iterative Reconstruction to an events (E) file directly. You must first convert it to a projection data (R) file. This is rebinning. Note that in converting an E file to an R file, the additional data recorded in the E file is not removed, it is simply reformatted. Once you have made the conversion and the data file type has been changed to the usual R file type, it can be processed and treated like any other nuclear SPECT study.

Since the original E file is not changed, you can rebin it multiple times using different settings to optimize image quality.

NoteRefer to γPET Option with BEACON for further information onPET Rebinning.


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PET Rebinning Control Panel

The rebin control panel is divided into four areas: Options Drop-Down Menu Selections Status Area General Program Selections File Selection Menu

Status Area

File Selection Menu

Options Drop-Down Menu

General Program Selections



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Options Drop-Down Menu SelectionsWhen you select any of the choices from the Options drop-down menu, a dialog box is displayed to allow you to specify additional processing parameters.

Select toChange Parameters

change processing parameter values including Zoom, Zoom offset, Matrix size, and Projections. Change Parameters is inactive for Whole Body studies.

Batch Mode process all files on the Workbench with the same parameters.Energy Windows

modify the centerlines and widths for one or two windows which were specified in the PHA form. This window displays the PHA spectrum and permits selection of the energy windows and widths.The program automatically finds the centerline for W1 (the peak of the photopeak), and sets its width at 30%. The centerline of W2 is then automatically set proportional to the photopeak, with a width of 30%. This is automatically done for all three heads.The only relevant windows in PET studies are windows 1 and 2 for setting the photopeak and Compton windows, respectively. Windows 3 and 4 are shown on the PHA screen, but are irrelevant. Do not turn them on.

Weights specify weighting for different types of events.Default for 1 window: Photo/Photo = 1, Photo/Compton = 0, Compton/Compton = 0Default for 2 windows: Photo/Photo = 1, Photo/Compton = 1, Compton/Compton = 0Weights are used to vary the influence of the photopeak and Compton peak energies. Weights is only active if energy windows have been selected. The defaults should be sufficient for most studies. C/C would only be used for the lowest count studies.


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Acceptances modify either axial or transverse acceptance angles.Defaults: Axial

12°Transverse

Head 1-2 = 90°Head 2-3 = 32°Head 1-3 = 90°

It is strongly recommended that the defaults not be changed.Whole Body Info modify Whole Body studies. This window is active only during

Whole Body studies.Planes allows you to adjust the number of coronal planes being viewed.Interplane spacing determines the thickness of the planes.Defaults:

Planes = 21Interplane spacing = 10 mm

The number of planes should be an odd number to allow for an isocenter.

Select to


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Change Parameters Pop-up Menu SelectionsWhen you select any of these choices from the Change Parameters menu, a pop-up menu appears with additional selections.

Select toZoom magnify the data. Performs the same function as Magnification on

the Acquisition Information form.Options:

0.851.001.151.331.501.672.002.503.004.00

Default: 1.00Higher magnifications are used for pediatric and brain studies.

Zoom Offset determine the axial zoom center of the field of view (FOV).Options:

Upper = centers the zoom from the upper limit of FOVCenter = centers the zoom on the center of FOVLower = centers the zoom from the lower limit of FOV

Default: CenterZoom offset is determined by the zoom factor.


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Matrix Size specify the final output matrix size for projections.Options:

64 X 64128 X 128256 X 256

Default: 128 X 128Projections specify the total number of projections.

Options:120128180

Default: 180

Select to


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Status AreaThis area provides online help, instructional assistance, and operational progress information regarding the rebin processing. For example, functions that take a noticeable amount of time to accomplish may display a processing message.

File Selection MenuThe file selection options menu displays the patient name, patient ID, and acquisition ID for each file. From this menu, any patient file loaded on the Workbench may be selected.

This section of the Rebin control panel also contains arrow buttons for moving sequentially between files.

General Program SelectionsSelect toProcess begin processing the data.Stop stop the processing.Restart reload the first input file in the input list.Help display the online help window.Done exit the rebin program.


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Rebinning a StudyThe following is an example of how to run PET Rebinning interactively during a PET tomographic process. Rebinning is defaulted to run automatically during a PET process.

Rebin PET Data

The main rebin panel appears.

Rebinning default parameters are set for optimum image quality.

1. Select Process to begin processing the study.

The PHA Display panel appears.

Procedure DetailsRebinning a File


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2. Adjust PHA values as desired. Ensure a 30% window centered on pho-topeak for all three heads. PHA default parameters are set for optimum image quality.

3. Select Done. Status messages, similar to the follow-ing, appear:

Creating File /img/P16539/R25RebinningPercent Complete: 67

After rebinning, the geometric correction is applied and the data file type changes to the usual R file type with default image ID gcr rebin. The file can then be pro-cessed as in other nuclear SPECT stud-ies.

4. Select Done to exit the PET Rebinning program.

Procedure DetailsRebinning a File

NoteFor information on PHA values, refer to the PHA section in AXIS/IRIX Acquisition Reference.


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SPECT Motion CorrectionMotion Correction adjusts for patient motion that occurred during an acquisition. Patient motion can introduce artifacts in reconstructed slices. The artifacts often introduce false defects or make existing defects difficult to characterize. Motion Correction is accomplished by comparing each acquired projection to a re-projected image (similar to maximum pixel raytrace) computed at the same acquisition angle. Motion Correction can only be used with SPECT raw data files. It is applied to the raw data before filtering, reconstructing, and reformatting.

NoteMotion Correction is not applied to the transmission data.

NoteMotion Correction will only run in a SPECT process and cannot be set to automatic. For further information on SPECT Motion Correction, refer to Reviewing and Analyzing the Study.


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Motion Correction Control Panel

The Motion Correction control panel is divided into three areas: Dynamic Help and Instruction Area Motion Correction Controls General Program Selections

Dynamic Help and Instruction AreaThis area provides online help, instructional assistance, and operational progress information regarding Motion Correction. For example, functions that take a noticeable amount of time to accomplish may display a processing message.

Motion Correction Controls

Dynamic Help andInstruction Area



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Motion Correction ControlsLeft-click on toThreshold set the threshold that defines the organ of interest highlighted in

the cross-sectional slices displayed in the image window during the process mode.

Axis specify x and y correction or only y correction. If motion correction fails in the x direction for fan beam data, correct only in the Y direction. If patients move, they typically move in a vertical direction.Choices include:

X & YY Only

Default: Y Only Set Slices toggle on to set the bounds of slice generation according to the

positions of the horizontal slice bars. - generate slices for the entire file when in process mode. Do

not set the slices according to the positions of the horizontal slice bars.

- use the positions of the horizontal slice bars to limit the number of slices to generate. This is the ON position.

Select Set Slices to toggle it off.Default: ON

Review Projec-tions

display a cine and sinograms of the current file.

Select Object display the slice masks with the threshold applied.

Compute Correc-tion

apply the motion correction algorithm.


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General Program SelectionsLeft-click on toApply Correction & Save

save the motion corrected raw data file.

Prior and Next Image

scroll backward or forward through the available images.

Prior and Next Screen

scroll backward or forward through the next screen of images.

Prior and Next File scroll forward or backward through the available files in the Selected File List.

Info display an Info Box.Options:None

No Info Box displayed.Long

Info Box full length of screen.Short

Displays a short style Info Box.Default: None

Label create an label on the motion corrected image.Lightbox Store save the Image Window as a lightbox image.Restart restart the program for a new selection of Workbench files.Help display online help information.Done exit the program.


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Motion Correcting a StudyMotion Correction is always an interactive process. You must complete Motion Correction during a complete SPECT tomographic process. The following is an example of SPECT Motion Correction during a Bone SPECT tomographic process.


SPECT Motion Correction begins:

The Image Window and control panel are displayed. A cine is shown in the upper-left corner of the Image Window with horizontal and vertical sinograms beneath the cine.

1. Left-click and drag left on the slice grips to limit the area of interest with the slice bars.

2. Review the cine display and sinograms for patient motion.

Procedure DetailsMotion Correcting a Study


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Process Mode

3. Click Select Object. The image window is cleared and then the slice masks with the threshold applied are displayed.

4. Adjust Threshold so that only the organ of interest, isolated from other organs, appears in the Image Window.

5. Select the organ of interest in the Image Window.

The areas to be examined for motion appear highlighted in white.

Compute Correction becomes sensitive.

6. Examine the slices to ensure that only the organ of interest is highlighted.



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7. If other areas are highlighted, adjust Threshold until only the organ of interest is visible.

8. Select Compute Correction to begin the motion correction algorithm.

While the algorithm is applied for up to three iterations, depending on the study, the Dynamic Help and Status Informa-tion area indicates the progress with messages similar to the following:

Iteration 1:Correcting 25 of 60



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Review the Results

9. Observe the results of the correction using the slice bars as a steady reference for viewing.

10. To re-process the images and refine the correction, adjust Threshold and then select Compute Correction.

After correcting the images, the Image Window shows before and after correc-tion cine displays and sinograms side by side. Mode automatically returns to Review.


NoteIf you re-process the study, the current corrected images will not be saved. Save the current results by selecting Apply Correction & Save before re-processing the study.

NoteAlways process Y Only first as most patients move vertically. If the image does not align correctly, process X and Y for vertical and horizontal motion correction.


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Save the Images

11. Select Apply Correction & Save to save the corrected slices.

12. Type the name of the new image file.

A dialog box is displayed with the default image ID “NoMotion.”

13. Select OK. The corrected slices are saved in a new raw data file with file type R to the patient directory (with Auto Save toggled on) and placed in the Selected File List. The Dynamic Help and Status Information area displays the following message:

New views have been saved.

14. Select Done to exit SPECT Motion Correction.


NoteFor further information on SPECT Motion Correction, refer to Reviewing and Analyzing the Study.


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2D PrefilterA control panel, an Image Window and a graph window appear when Prefilter is selected.

The Image Window displays a before and after image of each frame being filtered. The unfiltered images appear above the filtered images.

The graph window displays a visual representation of the selected filter. The graph axes and labels are displayed in white. The x-axis represents the spatial frequency in cycles/pixel. The y-axis represents relative amplitude in proportional units.

The power spectrum curve is displayed in green. It is drawn in the frequency domain. The power spectrum curve is scaled by a base 10 logarithm and is smoothed by a 3-point running average.

The 10% noise component line is displayed in yellow. The position of this line is the level at which there is 90% probability that all of the image noise lies in the part of the green power spectrum line that is below the yellow line. In other words, most of the noise which appears in the image is contained in the part of the green line that is below the yellow line.

NoteFor more information concerning the Prefilter program and parameter adjustments, refer to Reviewing and Analyzing the Study.


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2D Prefilter Control Panel

The Prefilter control panel is divided into four areas: Filter Selections Status Area Filter Control(s) General Program Selections

Filter Control(s)

Filter Selections

Status Area



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Filter Selections

Status AreaThis area provides online help, instructional assistance, and operational progress information regarding the prefilter. For example, functions that take a noticeable amount of time to accomplish may display a processing message.

Select toFilter select a filter:

Low PassMetzWiener

Low Pass is the only filter that should be used for tomographic studies.

Dimension specify the dimension that is used to view the study. Three selections are available.

2D1D Axial1D Transverse

Default: 2DIsotope specify which isotope is used in a study. This selection is inactive

when a Low Pass filter is selected.Collimator specify the collimator used in a study. This selection is inactive when

a Low Pass filter is selected.Distance specify the distance for a study. Distances are listed in 5 cm

increments. This selection is inactive when a Low Pass filter is selected.


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Filter Control(s)


Select toOrder control the slope and adjust, as necessary, to optimize image

quality. This can be adjusted in the provided text entry field or the Order valuator may be used. Order is available with a Low Pass filter only. The recommended Order value is 1.

Cutoff control the frequency and adjust, as necessary, to optimize image quality. This can be adjusted in the provided text entry field or the Cutoff valuator may be used. The cutoff value should be 5% of the noise component for the displayed dataset. Cutoff is available with a Low Pass filter only. The recommended Cutoff value is 0.50.

Select toHanning Window

apply the Hanning window edge attenuation during filtering. This button is inactive while using a Low Pass Filter.

Frame to Frame

recalculate the filter for every frame of the study. This button is inactive while using a Low Pass Filter.

Batch Filtering

filter all selected files using the parameters selected for the first file.Default: Off

Next File load the next available file when more than one file is listed on the Workbench.

Next Interval load the next available interval for review when filtering a gated study. This button is inactive while using a Low Pass Filter.

Filter File process all images after filter parameters have been selected. A new patient file is created, but not written to disk at this time.

Restart restart Prefilter.Help display the online help window.Done save the filtered file, exit Prefilter, and close all associated windows.


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Prefiltering a StudyThe following is an example of how to run prefiltering interactively during a PET tomographic process. Prefiltering is defaulted to run automatically when selected to run. You can also set Prefiltering to run in Gallery Mode.

Prefilter a Study

The Filtering Parameters values were set in the program preferences:

Filter: Low PassOrder: 1Cutoff: 0.50

Procedure DetailsPrefiltering a Study

NotePrefiltering should only be used on Low Count Tomo studies which have less than 6 million counts. Check the console window for the number of events in the file. Specifically, check the total events rebinned.

NoteThese values are dependent on the type of study being processed.


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1. Select Filter File to process all the images in the current file.

2. When filtering is satisfactory, select Done to exit Prefilter.

Procedure DetailsPrefiltering a Study

NoteDo not over-filter the data. Excessive filtering may show defects less clearly.

NoteFor further information on Prefiltering, refer to Reviewing and Analyzing the Study.


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Gallery ModeStandard Mode allows you to prefilter an image using the 2D Prefilter control panel. Gallery Mode will automatically generate three to thirteen prefiltered images through system operations.

Set the number of gallery images to create and the increment between images in the preference editor. The gallery is created during processing. The image filtered with the filter values for that files (no-AC, UAC, NUAC, etc.) is placed in the center of the gallery range. You can select the best prefiltered image to use from the three to thirteen images. The range of the image filter value is based on the number selected in the preferences for Increment. The following image represents what the Interactive Gallery will look like with the following preferences set:

Increment = 0.03 Filter Type = Low Pass Cutoff value = 0.30


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Transverse ReconstructionTransverse Reconstruction generates transverse slices from raw acquisition data using Filtered Backprojection or Iterative Reconstruction. The method of reconstruction will be determined by the available data and the selected preferences.

Reconstruction Control Panel

The Reconstruction control panel is divided into four areas: Options Drop-Down Menu Selections Status Area General Program Selections File Selection Menu




File Selection Menu

Status Area

NoteFor further information on Transverse Reconstruction, refer to Reconstruction Resource.


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Options Drop-Down Menu SelectionsWhen you select any of these choices from the Options drop-down menu, a dialog box is displayed to allow you to specify additional processing parameters.


change processing parameter values including Algorithm and Matrix. Filter is only included for Filtered Backprojection.

Batch mode process all files on the Workbench with the same parameters.Cine display the input projection data sequentially in “movie” mode,

running through three cycles and then stopping. Cine rate is not adjustable.

Sinogram display a Sinogram of the input projection data calculated from the data between the first and last selected slices.

Clear Display refresh the window. Right-click to clear the display.Info Box display a pull-down menu containing three format selections for

viewing patient information. Selections include:None = displays no patient informationShort = displays an abbreviated version of the patient info fileLong = displays the full version of the patient info file

Store Lightbox display a dialog box containing four fields and two buttons used to enter the patient information and construct a lightbox image of the screen to be stored.


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Select toAlgorithm select the algorithm type and the range of projection data to use in

the reconstruction. There are four algorithms supplied:FBP = Selects an filtered backprojection reconstructionOS ML-EM select = Selects an iterative reconstruction using ordered subsetsML-EM all = Selects an iterative reconstruction using the projection data

The OS algorithms are only available if the projection data can be segmented into ordered subsets.

Filter display a list of filters that may be used with backprojection. The filter list contains the postfilter and ramp options along with a list of discreet filters containing fixed parameters. This button does not appear for iterative reconstruction.

Matrix display a pull-down menu for setting the matrix size of the reconstructed images. “Default” is equal to the x matrix size of the input projections. There are four supplied values:

Default64 x 64128 x 128256 x 256

Default sets the reconstruction matrix to the same size matrix in which the study was acquired.


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Change Parameters Text Entry SelectionsAny of these choices from the Change Parameters menu can be adjusted in the text entry field provided.

Select to Image ID identify the reconstructed slices. It is a 10-character string

that is displayed in the Patient Index. Diameter(cm) adjust reconstruction diameter in centimeters. The default

is the input projections unzoomed field of view.Offset 1(cm) offset the x center for off-center zoomed reconstructions in

centimeters. The default is 0.0 cm.Offset 2(cm) offset the y center for off-center zoomed reconstructions in

centimeters. The default is 0.0 cm.Center slice adjust slice number of the center image of the set of

reconstructed images.Slices adjust the number of reconstructed slices.

In the automated processing macros, the slices default is 83. This includes all slices in the field of view.

Slice thickness adjust the thickness of the reconstructed slice in pixels. The default is 1.

Start angle adjust the starting projection for reconstruction using the projection range, specified in degrees. It is active only for the selected data algorithm; disabled otherwise. The default is generally 45°.

Iterations adjust the number of repetitions to perform during reconstruction of the data.

NoteExcept for Iterations and Slice Thickness, the reconstruction parameters can be adjusted using the graphical user interface.

NoteEnsure that the same Center Slice and Number of Slices are used when using Iterative Reconstruction on Attenuation Corrected data.


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Status AreaThis area provides online help, instructional assistance, and operational progress information regarding the reconstruction. For example, functions that take a noticeable amount of time to accomplish may display a processing message.


File Selection MenuThe file selection options menu displays the patient name, patient ID, and acquisition ID for each file. From this menu, any patient file loaded on the Workbench may be selected. This section of the Reconstruction control panel also contains arrow buttons for moving sequentially between files.

Select toReconstruct begin reconstruction of the selected slices.Stop interrupt the reconstruction in progress.Restart reload the first input file in the input list.Help display the online help window.Done exit Iterative Reconstruction.


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Reconstructing a StudyThe following is an example of how to run transverse reconstruction interactively during a tomographic process. Transverse Reconstruction is defaulted to run automatically.

Reconstruct Study


Procedure DetailsReconstructing a Study


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Adjust Reconstruction Diameter

1. Use the resizing grip (on either reference frame) to modify the reconstruction diameter, for example, a pediatric patient.

The reconstruction diameter cannot be greater than the original data values. If you change the diameter outside the original data range, the maximum possi-ble value is used. A warning message appears indicating this condition. Note that for this step, you can use either resizing grip.


2. Move the positioning grip in the “Offset 1" (left) reference rectangle to center the region of interest in the rectangle.

This step involves moving both the left and the right reference rectangles so the region of interest is centered in each rectangle. For this step, you need to center both reference images individu-ally.


NoteTo return Recon Diameter to the default value, press Restart.

NoteTo return Offset 1 or Offset 2 to default values, press [F1] and then [ENTER] in the appropriate text entry field.


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3. Move the positioning grip in the “Offset 2" (right) reference rectangle to center the region of interest in the rectangle.

A reference slice appears under the rect-angles.

Determine Region of Interest Center Slice

4. Drag the diamond grab box to adjust the number of slices in the region of interest.

Right-click to clear the sample slices dis-played in the Image Window.

5. Drag the center line to determine the placement of the center slice in the region of interest, if necessary.

6. Review the sample reconstructed slice.



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Review Reconstruction Parameters

7. Review all reconstruction parameters to modify the following, if necessary:

AlgorithmFilterMatrixImage ID

Options → Change Parameters

Reconstruct Slices

8. Select Reconstruct to reconstruct the images.

After reconstructing the study, the recon-structed images are saved to the Work-bench Selected File List and to a separate file in the patient directory.

9. Select Done to exit Transverse Recon.


NoteFor further information on Transverse Reconstruction, refer to Reconstruction Resource.


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3D Postfilter3D Postfilter removes unwanted effects of high frequency noise, by applying a three dimensional filter to reconstructed images. A control panel, an Image Window and a graph window appear when Postfilter is selected.

The Image Window displays a before and after image of each frame being filtered. The unfiltered images appear above the filtered images.

The graph window displays a visual representation of the selected filter. The graph axes and labels are displayed in white. The x-axis represents the spatial frequency in cycles/pixel. The y-axis represents relative amplitude in proportional units.

The power spectrum curve is displayed in green. It is drawn in the frequency domain. The power spectrum curve is scaled by a base 10 logarithm and is smoothed by a 3-point running average.

The 10% noise component line is displayed in yellow. The position of this line is the level at which there is 90% probability that all of the image noise lies in the part of the green power spectrum line that is below the yellow line. In other words, most of the noise which appears in the image is contained in the part of the green line that is below the yellow line.

NoteFor more information about Postfiltering, refer to Reviewing and Analyzing the Study.


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Postfilter Control Panel

The Postfilter control panel is divided into five areas: Filter Selections Status Area Filter Control(s) File Parameters General Program Selections

Filter Control(s)

Filter Selections

Status Area

File ParametersGeneral Program Selections


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Filter Selections

Status AreaThis area provides online help, instructional assistance, and operational progress information regarding the postfilter. For example, functions that take a noticeable amount of time to accomplish may display a processing message.

Select toFilter select a filter:

Low PassMetzWiener

Low Pass is the only filter that should be used for tomographic studies and the only filter available for BEACON studies.

Distance specify the distance for a study. Distances are listed in 5 cm increments. This selection is inactive when a Low Pass filter is selected.

Isotope specify which isotope is used in a study. This selection is inactive when a Low Pass filter is selected.

Collimator specify the collimator used in a study. This selection is inactive when a Low Pass filter is selected.


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Filter Control(s)

File Parameters

Select toOrder control the slope and adjust, as necessary, to optimize image

quality. This can be adjusted in the provided text entry field or the Order valuator may be used. Order is available with a Low Pass filter only.

Cutoff control the frequency and adjust, as necessary, to optimize image quality. This can be adjusted in the provided text entry field or the Cutoff valuator may be used. The cutoff value should be 5% of the noise component for the displayed dataset. Cutoff is available with a Low Pass filter only.The Cutoff varies and defaults to the 5% noise component level in PET studies.

Select toImage ID identify the files being filtered.Slice Thickness

adjust thickness of each slice in mm. This value can be changed by entering a value in the text entry field.


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General Program SelectionsSelect toPrevious Screen

display the previous frames in the file. It will display up to 8 frames.

Next Screen display the previous frames in the file. It will display up to 8 frames.Batch Filtering

filter all selected files using the parameters selected for the first file. Batch Filtering can be toggled on or off.Default: Off

Next File load the next available file when more than one file is listed on the Workbench.

Filter File process all images after filter parameters have been selected. A new patient file is created, but not written to disk at this time.

Write File write the current filtered files to disk. This selection does not become active until after Filter File has been selected.

Restart restart Postfilter.Help display the online help window.Done save the filtered file, exit Postfilter, and close all associated

windows.


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Postfiltering a StudyThe following is an example of how to run postfiltering interactively during a tomographic process. 3D Postfilter is defaulted to run automatically during the process.

You can also set Postfiltering to run in Gallery Mode.

Postfilter Study

The following parameters are set in the program preferences:Filter: Low PassOrder: 1Cutoff: 0.50

The first frames displayed will be the middle frames. The graph window dis-plays the optimized filter curve including the image power curve and the filter curve.

Procedure DetailsPostfiltering a Study

NoteThese values are dependent on the type of study being processed.


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Review All Filtering Parameters

1. Review all filtering parameters and modify any, if necessary:

Filtering valuesImage ID

Filter The File

2. Select Filter File to process all the images in the current file.



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3. Observe the effect on the filtered images as compared to the unfiltered images.

If the filtering is unacceptable: a Adjust Order and Cutoff.b Select Filter File.

Write File and Exit

4. Select Write File. The filtered file is automatically saved to the Workbench Selected File List.

5. Select Done to exit 3D Postfilter.


NoteFor more information about Postfiltering, refer to Reviewing and Analyzing the Study.


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Gallery ModeStandard Mode allows you to postfilter an image using the 3D Postfilter control panel. Gallery Mode will automatically generate three to thirteen postfiltered images through system operations.

Set the number of gallery images to create and the increment between images in the preference editor. The gallery is created during processing. The image filtered with the filter values for that files (no-AC, UAC, NUAC, etc.) is placed in the center of the gallery range. You can select the best postfiltered image to use from the three to thirteen images. The range of the image filter value is based on the number selected in the preferences for Increment. The following image represents what the Interactive Gallery will look like with the following preferences set:

Increment = 0.03 Filter Type = Low Pass Cutoff value = 0.30


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OverlayOverlay displays the transverse non-attenuation corrected slices from the primary energy window and the transverse attenuation map file simultaneously. Overlay is used to evaluate whether the attenuation map is satisfactory, and also to check for patient motion between the emission and transmission scans.

NoteOverlay is only used during a process that incorporates BEACON. Refer to BEACON Option and γPET Option with BEACON for further information on using Overlay in a Tomographic Process.

NoteFor more information on the Overlay Display program, refer to Displaying and Printing the Data.


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Overlay Display Control PanelThe Overlay Display control panel allows the overlay images to be manipulated.

Info BoxCreate a screen capture for later reviewZoom the images using the slider barDisplay Image Size

Fade the primary image

Move from one file to another if multiple files exist

Advance one screen at a time

Advance one image at a time

Toggle between Overlay Display or Combination Display

NoteOverlay will be displayed only if the Save Attenuation Map value in the Transverse Reconstruction preferences is set to Yes and BEACON is used in the process.


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Overlay Display Main Menu FunctionsSelect toConfigure toggle on and off primary and secondary image overlay.Image scroll backward or forward through the available images.Screen scroll backward or forward through the available screens.File scroll backward or forward through the available file pairs.Fade specify the contribution percentage of the primary images in the

display.100% Primary is the same as displaying only the primary images. 0% Primary is the same as displaying only the secondary images (100% Secondary).Options: 100%, 88%, 75%, 62%, 50%, 38%, 25%, 12%, 0% (Default 50% Primary)

Image Size specify the display matrix size to determine the number of images shown on the display.Options: 64 x 64, 128 x 128, 192 x 192, 256 x 256, 384 x 384, 512 x 512.

Zoom set the magnification factor of the displayed images.Lightbox Store store a Lightbox of the image window.Info Box select the Info Box format.

OptionsShort - short style Info Box (default)Long - full-length-screen Info BoxNone - no Info Box


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SPECT Uniform Attenuation CorrectionWhen gamma ray photons pass through a patient, they travel through both the organ of interest and the surrounding body tissues. As a result of the differences in tissue type and travel distances, those photons emitted from deeper within the body have a greater likelihood of being absorbed or scattered than those emitted closer to the body's exterior. This differential loss of photons due to passing through other tissues is referred to as attenuation.

The resulting image seems to have a ring around its outer edge because of the differentiated photon loss between these “inner” and “outer” regions. In fact, the outer portion of the image appears brighter, or hotter, than the cooler interior.

If you know the outline of the image, you can correct for this attenuation, that is, if the body is uniform. Each image is made of pixels. In SPECT Uniform Attenuation Correction, a series of distances are measured from each pixel to the image edge, which is defined by outlining the image.

With SPECT Attenuation Correction, each of these distances, or rays, is used to mathematically correct the reconstructed image and produce a new image. This method works well for SPECT Processing, but as it is only an approximate correction, it does not work as well for PET Processing.


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Uniform Attenuation Correction Control Panel

The Uniform Attenuation Correction control panel is divided into five areas:

File Information Status Area Ellipse Method Control General Program Selections Image Rotation and Control

Status Area

File Information


Ellipse Method Control

Image Rotation and Control


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File Information

Status AreaThis area provides online help, instructional assistance, and operational progress information regarding the Attenuation Correction. For example, functions that take a noticeable amount of time to accomplish may display a processing message.

Ellipse Method Control

Select toImage ID identify the files being Attenuation Corrected.Attenuation Coefficient

adjust the Attenuation Coefficient used to apply Attenuation Correction. To apply more correction, increase the coefficient. This causes the center to appear brighter. Conversely, to apply less correction, or darken the center, decrease the coefficient.Default: .05

Select toEllipse Fitting choose which fitting will be used. There are four choices:

1 per file1 per group (2)1 per group (3)1 per slice

Default: 1 per file.


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General Program SelectionsSelect toFit Ellipse(s) start the fitting process for all slices in the data set. The ellipse

should be fitted around the entire body outline to account for attenuation of any surrounding soft and hard tissue.

Cine On/Off start and stop the Cine display in order to step through the slices in the data set to view the ellipse fit. Cine On/Off is insensitive when you start the Attenuation Correction program. It becomes sensitive when Fit Ellipse(s) is started.

Zero Mask eliminate all data outside of the defined ellipse(s). This is a toggle On/Off button.

Apply start the correction process. Apply is insensitive when you start the Attenuation Correction program. It becomes sensitive when Fit Ellipse(s) is started. Applying the correction process requires more time if “1 per slice” or “1 per group” has been selected. Apply is the only menu selection you can make. If you select any other menu choice, the ellipses will be lost.

Restart restart Attenuation Correction.Help display the online help windowDone exit Attenuation Correction.

NoteThe Uniform Attenuation correction program applied to PET data differs from the Uniform Attenuation program that is applied to SPECT data. The output of the γPET version is a Raw Data (R) file whereas the SPECT Attenuation Correction program produces an Image (T) file.


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Image Rotation and ControlSelect toEdge Detection Threshold

adjust the Edge Detection Threshold control (valuator and/or text entry) to modify the ellipse algorithm. The Edge Detection Threshold is the percentage of the maximum pixel count in the image at which the counts at the edge of the image are detected.Default: 5%If the ellipse isn't automatically centering, try adjusting the threshold value to 35%.

Rotation display the angle at which the image is displayed. This value is not adjustable.

Rotation Adjustment

correct the image if the image is rotated compared to the vertical axis, so the fitting process delineates the outline better. Rotation Adjustment must be done before Ellipse fitting.

Slice Number select the slice number of the slice to be displayed, such as slice x of x. This allows viewing of any of the selected slices. If the ellipse per GROUP method was selected, the group number will appear above the valuator, not the individual slice number.


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Uniform Attenuation Correcting a StudyIf you select Uniform Attenuation Correction as part of the tomographic process, it will run automatically. The following example shows Uniform Attenuation Correction during a Bone SPECT tomographic process.

Perform Attenuation Correction

All correction parameters have been set in the program preferences:

Ellipse Fitting: 1 per fileZero Mask OffThreshold: 0.05Att. Coefficient: 0.110

The Attenuation Correction windows are displayed. The middle slice of the file appears in the Image Window. For example, if there are 22 slices in the file, slice 11 appears.

Procedure DetailsPerforming Uniform Attenuation Correction


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Adjust Rotation

1. Check that the image is aligned correctly with the vertical axis.

2. If necessary, adjust rotation.

a Select Rotation Adjustment.

b Position the pointer on the vertical bar handle.

c Left-click and drag to position the vertical bar along a sagittal plane that bisects the image.

d Select Rotation Adjustment to perform the data set rotation.

If the image is rotated compared to the vertical axis, adjust it so the fitting pro-cess delineates the outline.

This places a vertical bar in the image window.

The entire file rotates based on the bar position.

3. If you are not satisfied with the rotation angle, select Rotation Adjustment again.

The original un-rotated data set reappears.


NoteRotation Adjustment must be done before Ellipse fitting. Once you move to the next step, you must restart the program to change the rotation.

Rotated Image After RotatingData Set


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Modify Edge Detection Threshold

4. Use the Ellipse Size valuator if you want to change the edge detection threshold.

The edge detection threshold control lets you modify the ellipse algorithm. The default edge detection threshold value is 5% which means that the ellipse size is 95% of the maximum region.

Fit Ellipse

5. Select Fit Ellipse(s) to start the fitting process for all slices in the data set.

Modify Ellipse Shape

6. Modify the ellipse by left-clicking on any handle of the ellipse and dragging.

Fit the ellipse around the entire area of interest to account for attenuation of any surrounding soft and hard tissue.

The algorithm fits two half ellipses, an upper half and a lower half of the same center, to the data set. This provides a better body outline for oval slices. In this documentation, we will refer to the ellipse as being two half-ellipses.


NoteThe ellipse fitting method options are set in the program preferences.

Ellipse Handles

EllipseHandles


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Check Ellipse Fit

7. Check the ellipse fit for all slices or slice groups in the data set:

a Select Cine On/Off to step through the slices in the data set to view the ellipse fit.

b If you want to stop and check an individual slice, select Cine On/Off again.

c Select Average Slice n of n (or Slice Number x of x) valuator until the appropriate slice appears in the window.


NoteThe next steps only apply if you selected the ellipse per SLICE or the ellipse per GROUP method


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d Adjust the ellipse by moving the ellipse handles. Any changes made at this point will remain part of the fit.

e Select Cine On/Off to view the revised ellipse fit.

f Repeat this process until all ellipses are satisfactory for all slices or slice groups in the data set.

Apply Correction and Exit

8. Select Apply to start the correction process on the entire data set.

The new corrected file is stored in the patient directory, and in the Workbench Selected File List.

9. Select Done to exit the Attenuation Correction program.


NoteIf the ellipse per GROUP method was selected in the preferences, the group number will appear above the valuator, not the individual slice number.


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UNITE/3D ProcessingThe Multi-Volume Knitting option enables “stitching” of two to five image volumes. You can use one of three knitting options: Automatic, Sequential, or Simultaneous. These options are located in the Multi-Volume Knitting control panel.

The Automatic technique knits each of the two to five image volumes together, based on table position at the time of acquisition, without operator interaction. When complete, the Automatic Knitting Program displays transverse, sagittal, and coronal views of the knitted image. Manipulating any of the three views will cause reciprocal manipulation of the other two views.

The Tomographic Process defaults to the Automatic knitting method if Unite is selected to run. The Simultaneous and Sequential knitting methods may offer more control when desired. The Sequential method offers interaction as Whole Body sections are knitted in sequence. The Simultaneous knitting method presents all of the sections in a knitted fashion, but allows manipulation of each section as desired. Truncation is only applied to the knitted (partial) volume.

In any case, after knitting all of the volumes in sequential knitting, or a specific volume in simultaneous knitting, you may review the resultant knitted images by placing the cursor in a view and rotating images relative to one another.


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Multi-Volume Knitting Control Panel

Status AreaThis area provides online help, instructional assistance, and operational progress information regarding multi-volume knitting. For example, functions that take a noticeable amount of time to accomplish may display a processing message.


Status Area

NoteYou must have the UNITE software enable key installed to use Multi-Volume Knitting during a Tomographic Process.


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General Program SelectionsSelect toKnit choose the type of Multi-Volume Knitting.

Options:Automatic (default)SequentialSimultaneous

For greater image quality, there should be at least a 5 cm overlap of images during acquisitions. The knitting function will be performed, however, even with little or no overlap.

Fade designate the amount of translucence of the primary image. Each percent value specifies the amount of primary image contribution. Displaying the overlapped images may produce a dithered (or cross-hatched) pattern. This is normal.

100% Primary, 0% Secondary88% Primary, 12% Secondary75% Primary, 25% Secondary62% Primary, 38% Secondary50% Primary, 50% Secondary (default)38% Primary, 62% Secondary25% Primary, 75% Secondary12% Primary, 88% Secondary0% Primary, 100% Secondary

Zoom adjust the image magnification. Alternatively, you can enter a numerical value in the text entry box. Zoom has a default of .5.

Truncation adjust the truncation. Alternatively, you can enter a numerical value in the text entry box. Truncation has a default of 100%.

Decay Correction

toggle decay correction on and off. Decay Correction on adjusts the voxel value difference due to isotope decay during and within acquisition. The program defaults to Decay Correction On.Note: If isotope information is missing, this button is insensitive.


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Multi-Volume KnittingAs UNITE is an optional software product, Multi-Volume Knitting processing is a separate entity through Tomographic processing.

Knit Images knit image volumes together.Save Knitted Images

save the knitted composite volume to the Workbench.

Remove Cursors

remove the cursors from the Image Window. This button toggles on and off. The program defaults to Remove Cursors Off (cursors active).

Info Box choose the type of patient Info Box you want to display.Options:

None - No Info Box displayed (default).Long - Info Box full length of screen.Short - Displays a short style Info Box.

Lightbox Store create and store a lightbox file of the Image Window.Help display online help information.Restart restart the program and reload the files. The program will restart

in the mode at the time of selection.Done exit the program.

Select to

NoteFor information on how to run UNITE with Tomographic processing, refer to Multi-Volume Knitting.


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Oblique ReformatThe Oblique Reformat program reformats reconstructed images along any arbitrary axis. When Oblique Reformat is selected, an Image Window and a control panel appear.

The Image Window has two areas: a display area and a work area. The display area contains a selection of images from three views (general: coronal, sagittal, and transverse oblique; cardiac: oblique short axis, horizontal long axis, and vertical long axis). From these images, the work images for the three views are selected.

The display area contains two boxes, a white vertical box and a yellow horizontal box. The yellow box highlights the display images from which to select the work image for a particular view. The image where the two boxes overlap in the display area is the currently selected work image. The work image can be selected from the control panel or the image display area. The work image is also highlighted in a yellow box in the work area.

Overlaid on each work area is a region of interest (ROI) box. The slices and reformatting angle can be set from the Image Window by adjusting the size and position of the ROI box. The corresponding text entry fields are automatically updated. The solid lines of the ROI box indicate the first and last slices. The short tick marks represent the intervening slices. The diamond handle adjusts the size of the ROI symmetrically about the center line in the slice direction. The number of slices appears below the work image.

The circular handle adjusts the angle of the reformatted slices. A vertical line perpendicular to the Angle Selector serves as a reference for any angle adjustments.

You can move the square handle opposite the circle to view a work image other than the center of the selected set. This is useful for asymmetric studies.


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Oblique Reformat Control Panel

The Oblique Reformat control panel is divided into four areas: Options Drop-Down Menu Selections Status Area General Program Selections File Selection Menu

Status Area

File Selection Menu




NoteFor further information on Oblique Reformat, refer to Reviewing and Analyzing the Study.


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Options Drop-Down Menu SelectionsWhen you select any of the choices from the Options drop-down menu, a dialog box is displayed to allow you to specify additional processing parameters.


change processing parameter values.

Batch mode process all files on the Workbench with the same parameters.Zero Mask eliminate all data outside of the defined area(s). This is a toggle On/

Off button.Zero Angles and Centers

restore all angles to 0 and the volume to the original center.

Cine display the selected slices in the active view sequentially in “movie” mode, running through two cycles and then stopping. Cine rate is not adjustable.

Store Lightbox

display a dialog box containing four fields and two buttons used to enter the patient information and construct a lightbox image of the screen to be stored.

Info Box display a pull-down menu containing three format selections for viewing patient information. Selections include:

None = displays no patient informationShort = displays an abbreviated version of the patient info fileLong = displays the full version of the patient info file


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Select toType set the views to be used in the Image Window.

Options:Sag/Cor/Trans OblCardiac ObliqueWhole Body SPECT

Matrix specify the final output matrix size for projections.Options:

64128256Default (sets the final output matrix size to the same matrix size as the input file)

Slice Thickness (pixels)

select the slice thickness in pixels for all work images.

Pixel Size set the pixel size of the reformatted images. Changes to Pixel Size cause the image size to be zoomed up or down.

Slice Thickness (mm)

display the slice thickness in millimeters for all images. This is a display only. This value is not adjustable.


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View select the view being worked on in the Image Window. View selection is also done by clicking left in any of the work area displays.For non-cardiac studies, the view choices are:

CoronalSagittalTransverse Oblique

For cardiac studies, the view choices are:Short AxisH Long AxisV Long Axis

Image set the reference slice. Any slice can be evaluated by either entering the slice number in the text field provided or by adjusting the Image valuator.

ID enter an identifying label for the reformatted images.Angle define the angle in degrees of the slice selection plane for the

selected view. This is also graphically selectable.Axis cm(X, Y, or Z)

define the position of the work image in centimeters on the axis for the selected view. This is also graphically selectable.

Slices set the number of slices selected for each view. This value reflects the number of slices shown in the work area. This is also graphically selectable.

Reformat reformat the image for the selected view. If no images have been selected, this button is insensitive. Reformatted views are not placed in the patient directory until you exit the program.

OK return to the Options drop-down menu.

Select to


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Status AreaThis area provides online help, instructional assistance, and operational progress information regarding oblique reformat. For example, functions that take a noticeable amount of time to accomplish may display a processing message.


File Selection MenuThe file selection options menu displays the patient name, patient ID, and acquisition ID for each file. From this menu, any patient file loaded on the Workbench may be selected. This section of the Reconstruction control panel also contains arrow buttons for moving sequentially between files.

Select toReformat all views

reformat the image file for all views with slices selected.

Restart restart Oblique Reformat and loads the first selection from the Selected File list.

Help display the online help window.Done exit Oblique Reformat and store all reformatted views in the patient

directory if Auto Save is toggled on in the File drop-down menu.


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Oblique ReformattingThe following is an example of how to run oblique reformatting interactively during a SPECT tomographic process. Oblique Reformat is defaulted to run automatically during this process.

Reformat StudyThe slice thickness and image ID for transverse, sagittal, and coronal views are set.

Select Work Image For A View

1. Left-click on one of the images to select the work image or use the valuator controls for Image.

The work images are displayed in the work area of the Image Window. The axis or slice bars are overlaid on each view.

NoteGeneral SPECT files will be set for transverse, sagittal, and coronal views while myocardial SPECT files will be set for short axis, vertical long axis, and horizontal long axis views.

Procedure DetailsReformatting the Study


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If you know the exact value, enter a value for X, Y or Z in the reformatting parameters section of the control panel for that view.

2. Set the axis for each view:

a Place the pointer anywhere on the center bar except for the diamond and circular grab boxes.

b Left-click and drag the mouse.

c Release the mouse button when the axis is adjusted.


NoteYou can set parameters and reformat each view one at a time or all three views at one time.

NoteWhen a new value is entered for X, the change appears in the Y and Z views. Similarly, a change in Y appears in the X and Z views and a change in Z appears in the X and Y views.


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3. Set the angle of the axis for each view using one of the following methods:

Place the pointer on the circular handle, left-click and drag, and release button when the angle is set.

OR

Enter a value for Angle in the reformatting parameters section of control panel for that view.

If the images are displayed at an angle, you can correct the reformatted slices.



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4. Select the slice limits for each view:

a Place the pointer on the diamond grab box for one of the views.

b Left-click and drag the mouse to desired position.

c Release the mouse button.

Reformat Slices and Exit

5. Select Reformat all views to reformat slices for all three views.

The new oblique (O) files are placed in the Workbench Selected File List and in the patient directory.

6. Select Done to exit the Oblique Reformat program.


NoteFor more information about Oblique Reformat, refer to Reviewing and Analyzing the Study.


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Tomographic DisplayTomographic Display is used to display and analyze BEACON, PET, and SPECT data. Tomographic Display automatically occurs as the last step in the tomographic process.

Tomographic Display Menu


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Tomographic Display Menu SelectionsThe following buttons allow you to access individual Tomographic Display options. Use the Tomographic Display to analyze, label, and store patient files.

Select toSelect a New Patient

select a new patient study from the index.

Select a New Pair/Set

select the appropriate processed sets to be displayed.

Align and Zoom Images

realign the images and set zoom.

Image Display Options...

review the image display options.

Image Layout Options...

display the image layout options menu.

Localize Images...

display a control panel to align, zoom, and localize images.

Quality Control...

perform quality control functions.

Add Labels and Arrows...

add labels or arrows to the images.

Review Saved Lightbox Images

review the saved lightbox images.

Store the Image as a Lightbox

store the image as a lightbox.

Display Patient Information

display the patient information. If more than one set is selected, you must choose between single and dual Info Box formats.


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Advanced Applications

run 4D-MSPECT, Emory Cardiac Toolbox, QGS+, QPS, CEqual, and Brain Ratios from the Tomographic Display menu.

Done with Tomographic Display

exit the Tomographic Display menu and close all associated windows.

Done and Add This to the Review List

exit the Tomographic Display menu and adds the patient to the Study Review list.

NoteFor more information on Tomographic Display, refer to Displaying and Printing the Data.

Select to


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tux079

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