Breast Tomosynthesis - Detailed Proposal

1. Proposed Profile: Breast Tomosynthesis

Proposal Editor: David Clunie
Editor: TBD
Domain: Radiology

Summary

The IHE MAMMO profile has been one of the most effective IHE activities in terms of influencing the standardization of widespread support for the idiosyncratic requirements of mammography in general purpose PACS and viewers.

Breast tomosynthesis is in need of the same form of attention, and now is the time to act, since penetration of the user base is limited but increasing and users are demanding that their enterprise infrastructure support tomosynthesis rather than keeping it segregated in dedicated systems. Very soon, the problem of incompatible outside priors also will become apparent, if standards are not adopted.

The primary concern is the communication and display of reconstructed slices, and any synthetic views displayed from them, but standard support of projection images, and of CAD, is also desirable.

2. The Problem

Breast Tomosynthesis (Digital Breast Tomography (DBT)) is a new modality that shares many features with digital mammography, but has additional specific requirements to assure interoperability between vendors as well as satisfaction of user's functional requirements for display.

3. Key Use Case

A patient undergoes repeat screening mammography with tomosynthesis, and comparison is needed with last year's prior exam, with possibly a different vendor or model of acquisition modality, possibly at a different institution.

The interpreting radiologist requires that the current and priors be displayed with the necessary repertoire of mammography display features in the IHE MAMMO Profile, with the additional features required to properly display tomosynthesis reconstructed slices, synthetic views, and if necessary, tomosynthesis projection images and/or CAD, without resorting to the need for an acquisition-vendor-specific proprietary workstation.

Variants:

prior exam was tomosynthesis
prior exam was ordinary digital mammography (FFDM) only
current or prior tomosynthesis also includes FFDM ("combination study")
current or prior tomosynthesis also includes synthetic (MIP) view

4. Standards and Systems

IHE MAMMO
IHE MAWF
DICOM Breast Tomosynthesis SOP Class
DICOM Sup 165 Breast Projection X-Ray Image Storage SOP Class (in * development)

5. Technical Approach

A new profile that re-uses most of the IHE Mammo Profile will be defined, with additional behavior specific to the use-cases.

Acquisition Modality requirements will specify the use of the appropriate DICOM SOP Classes and any additional attribute requirements (consistent with the pattern used by IHE Mammo).

The Image Display will be required to handle both FFDM/DBT and DBT/DBT prior/current comparison use-cases with the appropriate set of features (same size, labeling, synchronized scrolling, etc.).

Unlike in the Mammo profile, print transactions are probably out of scope (unless someone can come up with a meaningful way to define printing of (selected?) DBT images.

Existing actors

Acquisition Modality
Image Display
Evidence Creator (if CAD)

New actors

None

Existing transactions

Modality Images Stored [RAD-8]
Evidence Document Stored [RAD-43] (if CAD)
Retrieve Images [RAD-16]

New transactions (standards used)

None

Impact on existing integration profiles

Probably None (unless do option to Mammo instead of separate profile)
MAWF if additional tomo workflow considerations (like new codes)

New integration profiles needed

Breast Tomosynthesis (unless do option to Mammo instead of separate profile)

Breakdown of tasks that need to be accomplished

identify SOP Classes to be used
list additional attributes
define viewing features required and reach user/vendor consensus
identify any tomo-specific workflow changes (including new codes, if any)
instantiate above in profile

6. Support & Resources

Several vendors and users have indicated their willingness to contribute.

7. Risks

There is a small risk that DICOM Sup 165 will not be completed in time, in which case the projection image aspect could be deferred.

CAD encoding for Tomosynthesis is not yet defined, though could theoretically be by the time this profile is completed; worst case, requirement of CAD display could also be deferred, though it has proven to be a very important feature of the existing IHE MAMMO profile.

8. Open Issues

Which viewing features to include.
Whether or not to include CAD.
Say anything about mandatory compression transfer syntax support

9. Tech Cmte Evaluation

<The technical committee will use this area to record details of the effort estimation, etc.>

Effort Evaluation (as a % of Tech Cmte Bandwidth):

35%

Responses to Issues:

See italics in Risk and Open Issue sections

Candidate Editor:

Antje S (with Renate H).