• Radiology Update:CT/MR Contrast Perfusion profile

Wim Corbijn van Willenswaard

Chair DICOM WG16Philips Healthcare

Introduction

• DICOM has standardized the ENHANCED MR IOD in 2002, followed by CT in 2004 and later for others.

• First IHE profiles for Enhanced IODs were created in 2009.

• Current update has removed major roadblocks for creating the necessary data at modalities, as defined by the profile.

• This will improve the acceptance of Enhanced SOP Classes by industry and users.

Agenda for this session

• Benefits of Enhanced DICOM• Dimension Module Concept

• Contrast Perfusion in CT/MR• Use case• Object Requirements

– Restrictions for Modalities, additional requirements• Display requirements

• Summary• Q&A

Benefits of Enhanced DICOM

• Modern Acquisition Techniques are fully covered. (no longer dependent on private attributes)

• Multi-frame packaging for fast transfer. (reduced number of files to transfer)

• Explicit Dimensions. (this provides context information, guiding (viewing) applications how to order/display the sequence of frames)

• Implementing Enhanced DICOM for one modality will pave the way for all other implementations which have the same structure

DICOM Dimension Module

• Two parts define how to traverse Multi-Volume data correctly:

• The dimension attributes (these play a role in the object dimension, like : time, position, echo, phase, contrast, …….):>Dimension Index Pointer (0020,9165)

• The index values for these attributes:>Dimension Index Values (0020,9157)

See notes

See notes

Temporal order for slice 1

Multi-Phase / Multi-Slice

time

Temporal Position Index

65

43

21

65

43

21

1 2 3

65

43

21

In-stack Position Number (Slice-Index) Frame number 1-6 Frame number 7-12Frame number 13-18

Slice Order for temporal 1

Image frames can be sorted/displayed independent of the frame order

4\1 4\2 4\3

Slice Order for temporal 2

Dimension index values:

Temporal order for slice 5

• IHE Profile PERF

Contrast Perfusion in CT/MR

Contrast Perfusion in CT/MR

• This Integration Profile facilitates the exchange of contrast enhanced images created as a stack of images at different timeslots, in order to demonstrate the uptake of a contrast agent over time

• The exchange of standard attributes for time and position allows for correct and convenient display on standard display systems

• This is a major improvement compared to the older single-frame DICOM image objects (where applications need to depend on proprietary timing attributes) offering improved interoperability

MR Perfusion Imaging

9

time

non perfused stroke area

Sig

nal

delayed perfusion

time-to-peak map

Requirements for creators1. A Volume may not be spread over Enhanced SOP Instances

(a Temporal Position may not be present in multiple objects)

2. Creator provides dimension indices for:• Stack ID• In Stack Position Number• Temporal Position Index

3. Data requirements:Image Type and Frame Type:

• Value 1: ORIGINAL• Value 2: PRIMARY• Value 3: PERFUSION

Functional Requirements for Image Display

1. Provide at least one viewport for display of frames with the same In-Stack Position Number (Slice-index).

(More viewports may be used for displaying images for other In-Stack Position Numbers = simultaneous scrolling)

2. Be able to scroll the images by Temporal Position Index for the same in-stack position (Temporal Position-index = time related movie).

Required display layout

Position = 1 Position = 2 Position = .. Position = n

Time = 1

Time = 2

Time = ..

Time = n

scro

ll

Alternative display layout

Time = 1 Time = 2 Time = .. Time = n

Position = 1

Position = 2

Position = ..

Position = n

Switching Position and Time

scro

ll

Data Requirements for DisplayAttribute Name Tag

Enhanced Contrast/Bolus Module

Contrast/Bolus Agent Sequence (0018,0012)

>Contrast/Bolus Administration Route Sequence (0018,0014)

   

Frame Type Value 3 (0008,9007)

   

Frame Content Sequence (0020,9111)

>Temporal Position Index (0020,9128) 

>Stack ID (0020,9056)

>InStackPositionNumber (0020,9057)

   

Time Offset value (0020,930D)

Summary• CT/MR Perfusion Imaging with Contrast profile is updated to be

in line with the modality way of working.

• Series can be stored in more than one object, but a Temporal Position (Volume) is always stored in one object.

• Extra explanation how to use the DIMENSION information.

• Use of the profile will facilitate the display of the more complex acquisitions on standard display systems.

• The other Enhanced Profiles will be updated to the same structure.

• Thank You

Any Questions?