1. Massachusetts General Hospital APIII 2007Harvard Medical School Evaluation of DICOM Supplement 122 at CWRU Ashok PatelRajnish GuptaJohn Gilbertson Case Western Reserve University Cleveland, Ohio

2. Massachusetts General Hospital APIII 2007Harvard Medical School CT Scanner Archive RIS Dedicated Workstation Radiology had a problem 1980s CT Scanner Archive Dedicated Workstation

3. Massachusetts General Hospital APIII 2007Harvard Medical School

5. Image Exchange Standard CT Scanner Archive RIS Dedicated Workstation Two Important Inventions CT Scanner Archive Dedicated Workstation PACS

6. Massachusetts General Hospital APIII 2007Harvard Medical School DICOM – an Image Exchange Standard: 1985: ACR (American College of Radiology) and NEMA (National Electrical Manufactures Association) published the first ACR-NEMA standard for radiology 1993: DICOM Digital Image COmmunications in Medicine CT Scanner PACS RIS Workstation Vendor 2 Vendor 1 Vendor 4 Vendor 3 DICOM

7. Massachusetts General Hospital APIII 2007Harvard Medical School DICOM A remarkably successful standard  Is the basis for virtually all PACS and multi-specialty Clinical Image Archives… Very large client community Very strong vendor community Over time, it has been responsive to technical and practice changes It managed by NEMA through open, collaborative, international working groups Working Groups maintain and extend different parts of the standard

8. Massachusetts General Hospital APIII 2007Harvard Medical School Device (Archive) Internal Information Model and Protocols Device (CT Scan) Internal Information Model and Protocols “CT Working Group” CT Scan Information Object Definition (IOD) Defined DICOM Protocol / Service  “Store” Working groups from different specialties can define IODs as needed… Criminally Simplified DICOM DICOM Information Model and Protocols DICOM Information Model and Protocols Transaction Convert Image Type: CT Patient ID Study ID Machine ID Date Size Radiologist Etc. Image Object Image & standardized clinical data and metadata Different for each image object class Multiple Modules Made up of

9. Massachusetts General Hospital APIII 2007Harvard Medical School Pathology, DICOM and WG 26 It was designed to be used by other (non-radiology) specialties and many have done so Initial work between Pathology and DICOM in the middle nineties October 2005: DICOM Strategic Planning Working Group (WG 11) invited a number of pathologist to Budapest to discuss the possibility a Pathology Working Group in DICOM December 2005: DICOM WG 6 established WG 26, with scope over all of pathology imaging

10. Massachusetts General Hospital APIII 2007Harvard Medical School LIS / Histology Bar coded Slides WSI Robot Image Archive / Server “Virtual Microscope” On Pathologist’s PC WSI Robot Image Archive / Server “Virtual Microscope” On Pathologist’s PC Pathology has a problem…

11. Massachusetts General Hospital APIII 2007Harvard Medical School WG 26 It is made up of pathologists, the WSI industry and senior members of DICOM who act as mentors Anyone can join, show up (and work) Seven formal meetings - Phoenix January 06, Madrid, Vancouver, Chicago, DC., Cologne, Pittsburgh (plus conference calls)

12. Massachusetts General Hospital APIII 2007Harvard Medical School WG 26 Major “initial findings”” –Most of DICOM could be used directly in Pathology, but –for DICOM to work in Pathology, three main issues had to be solved…

13. Massachusetts General Hospital APIII 2007Harvard Medical School Two of the three issues: –“Sub image access” –“Image size” Are outside the scope of this study Members of WG 26 are working with other parts of the DICOM community to solve these problems Image Server Image Client Entire Image Current View He’s panning to the left! Here are the appropriate tiles “Sub-image level access”

14. Massachusetts General Hospital APIII 2007Harvard Medical School Specimens

15. Massachusetts General Hospital APIII 2007Harvard Medical School Specimens in DICOM DICOM expects a Patient to be the subject of every image In pathology a Specimen is the subject of an image WG 26 has offered for public comment DICOM Supplement 122 which defines the place of a specimen in the DICOM information model as well as the specimen attributes that should be collected when a specimen is the subject of a DICOM image Patient Study Series Image Basic DICOM Hierarchy Very Simplified DICOM Specimen ?

16. Massachusetts General Hospital APIII 2007Harvard Medical School WG 26: Specimens in the DICOM Model Patient Study Series Image Criminally Simplified DICOM Modality Specimen LIS Specimen Information Object Definition (IOD) Pathology Modality Information Objects Definitions? (IOD) Second draft this summer “Specimen” can be associated with any type of image Relevant Specimen Identification and Processing data (expected to come from the LIS)

17. Massachusetts General Hospital APIII 2007Harvard Medical School Supplement 122: Specimen Attributes SS.3.1Scope The Specimen Module (see PS3.3) defines formal DICOM attributes for the identification and description of laboratory specimens when said specimens are the subject of a DICOM image. The Module is focused on the specimen and laboratory attributes necessary to understand and interpret the image. These include: –Attributes that identify (specify) the specimen (within a given institution and across institutions). –Attributes that identify and describe the container in which the specimen resides. Containers are intimately associated with specimens in laboratory processes, often “carry” a specimen’s identity, and sometimes are intimately part of the imaging process, as when a glass slide and cover slip are in the optical path in microscope imaging. –Attributes that describe specimen collection, sampling and processing. Knowing how a specimen was collected, sampled, processed and stained is vital in interpreting an image of a specimen. One can make a strong case that those laboratory steps are part of the imaging process. –Attributes that describe the specimen or its ancestors (see Section SS.1, above) when these descriptions help with the interpretation of the image. Attributes that convey diagnostic opinions or interpretations are not within the scope of the Specimen Module. The DICOM Specimen Module does not seek to replace or mirror the pathologist’s report.

18. Massachusetts General Hospital APIII 2007Harvard Medical School Device (Archive) Internal Information Model and Protocols Device (WSI) Internal Information Model and Protocols Working Group 26 Information Object Definition (IOD) Defined DICOM Protocol / Service  “Store” Working groups from different specialties can define IODs as needed… Very Simplified DICOM DICOM Information Model and Protocols DICOM Information Model and Protocols Transaction Convert Image Type: CT Patient ID Study ID Machine ID Date Size Radiologist Etc. Image Object Image & standardized clinical data and metadata Different for each image object class Multiple Modules Made up of Specimen Module SPECIMEN ATTRIBUTES IN DICOM: SUPPLEMENT 122

19. Massachusetts General Hospital APIII 2007Harvard Medical School Table A.32.X-1 SPECIMEN VL MICROSCOPIC IMAGE IOD MODULES IE ModuleReferenceUsage Patient C.7.1.1M Clinical Trial SubjectC.7.1.3U StudyGeneral StudyC.7.2.1M Patient StudyC.7.2.2U Clinical Trial StudyC.7.2.3U SeriesGeneral SeriesC.7.3.1M Clinical Trial SeriesC.7.3.2U EquipmentGeneral EquipmentC.7.5.1M ImageGeneral ImageC.7.6.1M Image PixelC.7.6.3M Acquisition ContextC.7.6.14M VL ImageC.8.12.1M Overlay PlaneC.9.2U SpecimenC.7.6.20M SOP CommonC.12.1M Specimen Module are Defined in a document, Written by a working group, Called a Supplement

20. Massachusetts General Hospital APIII 2007Harvard Medical School Specimens in DICOM Supplement 122 asks for the following data elements: 1.Specimen Container Identifier 2.Container Identifier 3.Specimen Identifier 4.Short Description of the Specimen (Text) 5.Detailed Description of the Specimen (Text) 6.Coded Description of the Specimen 1.(code | code system | code meaning) 7.Processing History especially fixation, embedding and staining 1.Specimen ID of Specimen Processed 2.Date Time of Processing 3.Type of Processing 4.Description of Processing

21. Massachusetts General Hospital APIII 2007Harvard Medical School The study After the DICOM Supplement 122 became available for public comment, investigators at Case Western Reserve University attempted to implement the supplement in their LIS to determine if the LIS could provide the specimen attributes requested in Sup. 122 and if there was important LIS data that the Supplement should request but does not Essentially we tried to write an LIS (Cerner Copath) query/report that could retrieve the proposed DICOM specimen data on Gross Specimens and Slides Looked at 5000 cases (~ 30000 gross specimens and slides)

22. Massachusetts General Hospital APIII 2007Harvard Medical School Specimen ID Part and Block identifiers were not problem A unique slide identifier could be constructed, but it required joining two tables. The result was a x.x slide number S05-100 A 1 2.3 A05-100 A 1 2.5 A05-100 A 1 3.1

23. Massachusetts General Hospital APIII 2007Harvard Medical School Specimen Description Pathologists descriptions of parts and blocks were “hidden” in large, multi-specimen narrative field that required extensive parsing This was a serious problem – the “native” LIS could not reliably provide specimen descriptions Coded specimen descriptions (part types, etc) were available but were often non-specific and non- descriptive (‘Big – Other”)

24. Massachusetts General Hospital APIII 2007Harvard Medical School Specimen Processing How was it fixed? FIXATION and STAINING are from the same dictionary How was it Embedded? NO DATA How was it Stained? FIXATION and STAINING are from the same dictionary An slide stained in H&E and fixed in B5 was reported as “stain = B5” There were multiple ‘types” of H&E processes depending on when the staining was done: HE Initial, HE, etc.

25. Massachusetts General Hospital APIII 2007Harvard Medical School Conclusions Our LIS could not implement SUP 122 without major changes This is not about DICOM, this is about our LIS systems The study showed serious limitations in the information model and implementation of our LIS when it comes to specimen level information Narrative field that contain data on multiple specimens (parts and blocks) are serious problems Histology data is not stored in sufficient detail Dictionaries are poorly implemented