What IHE Delivers

IHE Mammography: Workflow, Display,

and Dose Monitoring

Christoph Dickmann, Siemens HealthcareChristoph Dickmann, Siemens Healthcare

RSNA 2008 Informatics CoursesRSNA 2008 Informatics Courses

FFDM - not just another modality

Full Field Digital Mammography (FFDM) imaging has specific requirements:

High patient throughput (e.g. 300 patients/day)

“On-line” work-up, screening/ diagnostic

Common use of CAD (Computer Aided Detection)

Double (blind) reading

Importance of prior study comparisons

Image size, orientation, layout

Integration issues to be solved

Variances among vendors’ image data

Two types of image data

Hanging may look different on workstations

CAD markers may look different on workstations

Add supplemental images

Change procedure information at Modality

Hide low-quality or incorrectly labeled images from further use

Mammography Environment

Mammo IS

Procedure, Worklist, Procedure Step

FFDM Modality Workstation

CAD“For Presentation” Images“For Processing” ImagesMammo CAD Report

ArchivePatient dose information

Printer

Mammography Image ProfileValue proposition

Systems support DICOM objects enhanced for interoperability/ quality aspects FFDM modalities provide adequate information to

facilitate downstream applications

Image display and printing operations enable safe, effective and efficient diagnosesView and print images from multiple FFDM vendors consistently

Acquisition ModalityRich image information for high-quality display

Send both - FOR PROCESSING and - FOR PRESENTATION images with reference that ties them togetherAdditionally required DICOM attributes, e.g. Acquisition date & time, operator’s name Detector ID, software version Exposure time, filter material, positioner angle

Detection and indication of tissue vs. airPartial View Option - breast is larger than detectorSimilar for film digitizers (less requirements)

Image DisplayConsistent presentation & screen layout

CalibrationDICOM Grayscale Standard Function

Image hanging determined by:View Type (e.g. CC vs. MLO)View Type modifiers (e.g. Spot, Mag)Laterality Patient Orientation

IHE does not use for hangingSeries or study descriptionsSeries or study descriptionsImage order as acquired Image order as acquired Image orientation as acquiredImage orientation as acquired

R CCR CC L CCL CC

L MLOL MLOR MLOR MLO

Acquisition Matrix: Image Receptor e.g. 20,000,000 Pixels

4096

5024

2048

2560

Image DisplayConsistent pixel sizes (un)magnified

Display Matrix: Monitor e.g. 5,000,000 Pixels

Image DisplayConsistent sizing also with different

detectors

RR LLRR LLPrior exam fromPrior exam fromvendor A’s systemvendor A’s system

RR LL RR LLCurrent exam fromCurrent exam fromvendor B’s systemvendor B’s system

Different resolutionDifferent resolution Different pixel matrixDifferent pixel matrix

Fit images to same size: Relative (e.g. fit to viewport)Physical (true size)1:1 pixels (detector : screen)

Image DisplayContrast, annotations, CAD marks

Contrast Ability to use linear and sigmoid LUT Tissue vs. air detection: Window/ Center

adjustments are not applied to air

Image annotationsPatient identificationEquipment identificationTechnical factorsView: laterality, view, view modifier

CAD marks from Mammography CAD SROne or more sets of CAD marksFit to image orientation

Printing: Composer, Server Quality, annotations

True Size printing Physical object size Composer sends Requested

Image Size

Burn in a rulerJustify chestwall print with 5mm borders or less

Use display annotationsUse Presentation LUTUse maximum density valuesSupport 12 bit pixel depth

Minimal borders at chest wall

Mammo Acquisition Workflow

Value proposition

Now that I can create and consistently display Mammography images, how can image acquisition be handled reliably for routine and “exceptions”?

Routine: same as Radiology Scheduled WorkflowClearly record what is performed (differently) at the Modality coded valuesCorrectly display images from acquisitions of separate procedure stepsMark images of insufficient quality Correct certain image labeling

Mammography EnvironmentAcquisition Workflow view

“For Presentation” ImagesMammo CAD Report

Archive

Workstation

Mammo IS

Procedure, Worklist, Procedure Step

Procedure

FFDM ModalityWorklist,Proc. Step

Proc. Step

Mammo Acquisition Workflow Actors & Transactions – the IHE

environment

DSS = Department System Scheduler.Abbreviations on subsequent slides: OF = Order Filler. (M)PPS = (Modality) Performed Procedure Step

Mammo Acquisition WorkflowSupplemental views to a completed exam

Modality Archive WorkstationDSS/ OF *

Store supplemental images

MPPS in progressMPPS completed

Scenario: Supplemental image of implant displacement after screeningAppend case: Add image to current Procedure, e.g. “Screening bilateral” Tech selects from configured Modality protocol settings Modality sends a new MPPS with the protocol codes

DSS/OF may use these protocol codes, e.g. for notifying the Clerk/ TechImage Display selects presentation layout based on procedure/ protocol/ reason codes

Query/ Retrievescreening and implant images

* Note: For simplicity reasons, the diagrams show the PPS Manager as part of the DSS/OF

MPPS forwarded

Mammo Acquisition WorkflowFinish acquisition at another Modality

Scenario: Supplemental images acquired later, at another ModalityAvoid unscheduled acquisition with manual reconciliation at DSS/OFIt all depends on DSS/OF worklist behaviorModality queries Worklist (MWL) based on: Patient name/ ID, Accession #, Procedure ID

Archive WorkstationDSS/ OF

Query/ Retrieveimages from both Modalitiesas part of the same StudyModality 2

Store images

MPPS in progressMPPS completed

MPPS forwardedQuery MWL

Query MWL(patient-based)

MPPS in progress/ completedStore images

Modality 1

Mammo Acquisition WorkflowConvert procedure

Scenario: Convert diagnostic procedure from unilateral to bilateralRadiologist reviews images of left breast while patient still present.Radiologist decides that images of right breast are needed, too.Append case: Add images to current Procedure that is changed to “Diagnostic Mammography, bilateral” Tech adds reasons for changing the Procedure (new DICOM attribute: CP 886) Tech selects from a configurable Modality protocol set Modality sends a new MPPS with new procedure & protocol codes

DSS/ OF detects procedure change and updates Image Manager/ Archive.

Modality Archive WorkstationDSS/ OF

Store images of R breast

MPPS in progressMPPS completed

Query/ Retrieve imagesfor bilateral diagnostic exam

Procedure update: unilateral bilateralMPPSforwarded

Mammo Acquisition WorkflowRecall – patient returns for subsequent exam

Scenario: Screening recall for a unilateral diagnostic mammogramRadiologist assesses acquired images as “incomplete” (BIRADS 0). Patient has left and needs to come back for additional imaging.DSS/OF schedules a new Procedure (for the screening Order) with a specific Reason for Requested Procedure code value a reference to the original Study (Referenced Study Sequence)

Regular acquisition at ModalityImage Display presents both Studies based on Reason code and Study reference

Modality Archive WorkstationDSS/ OF

Store images (recall study)

MPPS

Query/ Retrieveimages from original and recall study

Query MWL (on recall) MPPS forwarded

Mammo Acquisition WorkflowReject images of insufficient quality

Scenario: Mark images as rejected for quality reasonsAfter completed acquisition, images are considered of insufficient qualityModality or Evidence Creator create a Key Object Selection (KOS) object Title is “Rejected for Quality Reasons” and explained by a Modifier References to all rejected images

Image Archive is configurable to provide or hide rejected images and KOSImage Display is configurable to present or hide rejected images and KOS

Modality or QA workstation Archive WorkstationDSS/ OF

Store rejection KOS

MPPS (Modality) orCreator PPS

MPPS forwarded

B) Rejected images are hidden or displayed

A) Rejected images are hiddenB) Rejected images are provided

AvailabilityNotification

A) Rejected images not part of query result

Q/R

Mammo Acquisition WorkflowCorrect view labels of images

Scenario: View, laterality or protocol are correctedAfter completed acquisition, incorrect view labeling is detected Modality or Evidence Creator create corrected images Copy most values except e.g. View Codes, View Modifiers, Laterality, Protocol Correct references from “For Presentation” to “For Processing” images Evidence Creator records its identifying data (Contributing Equipment Sequence)

Modality or Evidence Creator create a Key Object Selection (KOS) object Title is “Rejected for Patient Safety Reasons” References to all incorrect images (For Presentation & For Processing)

Image Archive & Image Display hide KOS and incorrect images

Modality or QA workstation Archive WorkstationDSS/ OF

Store rejection KOSStore corrected image(s)

MPPS (Modality) orCreator PPS

Q/R: incorrect imagesare not part of query resultIncorrect images

are hidden at Q/R

PPS forwarded

Availability Notification

Mammo Acquisition WorkflowSummary

Extend routine Scheduled Workflow Use of Protocol and Reason codes (DSS/OF, Modality) Scheduled and Performed Procedure Codes can vary.

Never empty Procedure or Protocol Code Sequences. Modality supports Patient-based Worklist Query

Image Quality Assurance results “Low quality” images can be marked or hidden Incorrectly labeled images can be corrected

Radiation Dose Monitoring in Mammography

FFDM Modality also implements the Acquisition Modality in the Radiation Exposure Monitoring IHE Profile

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Dose Analysis& Reporting

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Archive

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Radiation Dose Monitoring in Mammography

FFDM Modality can act as an Acquisition Modality in the IHE Radiation Exposure Monitoring Profile Modality reports patient dose Archive/ PACS receive and store dose reports RIS, Workstations, etc. process or display these reports

Dose Reports are DICOM Dose Reports for projection X-ray Required: dose of irradiation events Optional: accumulated dose over Study or Series Mammography Dose

• Organ-specific: laterality, fibroglandular dose, breast composition, compression

• Exposure: time, KVP, mA, entrance exposure at reference point

Summary

IHE Mammography Profiles make FFDM Modalities, PACS, Viewing Stations and Printers interoperable: Consistently use rich data in DICOM Mammography images Consistent pixel / image sizing Consistent windowing Consistent and correct image layout on screen or film Exactly defined procedures and workflow steps Flexibility in adding / changing workflow steps

IHE Radiation Exposure Profile enables monitoring radiation doses in Mammography

Take home

Mammography User Handbookwww.ihe.net/Resources/handbook.cfm Understand your interoperability issues Help for making purchase decisions

Technical Frameworkswww.ihe.net/Technical_Framework/ Technical requirements

SBI 2009 educational events

What IHE Delivers

Thank you!Thank you!Questions?Questions?