PACS TOMO COMPATIBILITY

Transcription

1 PACS TOMO COMPATIBILITY Documentation Control: Author Date Signature Issue F. Gigante 18-Jul-16 Approval A. Rossi 18-Jul-16

2 i. Document versions Version Date Author Changes Jul-16 F. Gigante First Version Nov-16 F. Gigante Images set link updated (Added CT and fixed patient and image orientation DICOM fields) Document Versions Page 2 of 10

3 ii. Table of contents I. DOCUMENT VERSIONS...2 II. TABLE OF CONTENTS INTRODUCTION DIGITAL BREAST TOMOSYNTHESIS IMAGE STORAGE TOMOSYNTHESIS DICOM IMAGE LATERALITY CHECK TOMOSYNTHESIS DICOM IMAGE POSITION CHECK TOMOSYNTHESIS DICOM WINDOW LEVELS CHECK PER FRAME WINDOW LEVELS (DEFAULT) SHARED WINDOW LEVELS COMPUTED TOMOGRAPHY IMAGE STORAGE TEST IMAGES...9 Table of contents Page 3 of 10

4 1 Introduction IMS Giotto Tomo and Giotto Class system create the following DICOM images: SOP Class UID SOP Class Name Digital Mammography Image Storage For Presentation Digital Mammography Image Storage For Processing Breast Tomosynthesis Image Storage Computed Tomography Image Storage The first two sop classes are used for the standard 2D mammo images. The last two sop classes are used for the tomo multislice images and for the synthetic image (G-View). Introduction Page 4 of 10

5 2 Digital Breast Tomosynthesis Image Storage The tomosynthesis Breast Tomosynthesis Image Storage images have some new fields to store the DICOM information. The most often issue are present when a not compatible PACS try to read some of the following information: Image Laterality Image Position Image Window Levels Several PACS could not have a complete compatibility with tomo images: they could not correctly read the previous information. If the PACS cannot read the Image Laterality and or the Image Position, it cannot display correctly the laterality and position labels over the image and it cannot position correctly the images by mean of visualization hanging protocols. If the PACS cannot read correctly the Image Windows Levels the images will be displayed very gray, without any contrast. 2.1 Tomosynthesis DICOM Image Laterality Check The Image Laterality is store in the following DICOM field (Frame Laterality): Shared Functional Groups Sequence(5200,9229) Sequence that contains the Functional Group Macros that are shared for all frames in this SOP Instance and Concatenation > Frame Anatomy Sequence (0020,9071) Identifies anatomic characteristics of this frame >> Frame Laterality (0020,9072) Laterality of body parts. Enumerated Values: R=right, L=left 2.2 Tomosynthesis DICOM Image Position Check (0054,0220) ViewCodeSequence >Code Value (0008, 0100) According to parameters set on the Giotto console and DICOM standard Digital Breast Tomosynthesis Image Storage Page 5 of 10

6 >Code Scheme Designator (0008, 0102) Always SRT >Code Meaning (0008, 0104) According to DICOM standard >View Modifier Code Sequence (0054, 0222) 2 Sequence that provides modifiers for the view of the patient anatomy. 2.3 Tomosynthesis DICOM Window Levels Check The Window levels may be stored in two different way: one value per frame or one value for all the frames. The default option to store the images is one value per each frame Per frame Window Levels (default) Per-frame Functional Groups Sequence (5200,9230) Contains the Functional Group Macros corresponding to each frame of the Multi frame Image > Frame VOI LUT Sequence (0028,9132) >> Window Center (0028,1050) >> Window Width (0028,1051) >> VOI LUT Function (0028,1056) Shared Window Levels It's possible to store a single couple of Window Levels value for all the frames. The shared Window Levels may improve some PACS Open Raffaello and click on the folllowing option: Tools Global Admin Settings Configuration Station Configuration Tomo Reco Settings and check the option Shared WL (see fig.1). Digital Breast Tomosynthesis Image Storage Page 6 of 10

7 Fig. 1: Shared WL The shared Window Levels will be stored inside the following shared sequence: Shared Functional Groups Sequence (5200,9229) > Frame VOI LUT Sequence (0028,9132) >> Window Center (0028,1050) >> Window Width (0028,1051) >> VOI LUT Function (0028,1056) Digital Breast Tomosynthesis Image Storage Page 7 of 10

8 3 Computed Tomography Image Storage Raffaello 4.4 can create Computed Tomography (CT) images instead of standard Digital Breast Tomosynthesis image. This approach has advantages and disadvantages: Advantages The tomo and synthetic images in CT format can be stored and displayed probably on every PACS. Disadvantages The PACS could not correctly display all the mammo information and could not use a mammo display hanging protocol. Keep in mind this issue is not present if you use Raffaello RWS 4.4 to display the tomo and synthetic images in CT format. Computed Tomography Image Storage Page 8 of 10

9 4 Test Images You can download the following zip file: This demo set contains images in DBT format and CT format. The following positioning example are syntetic images stored as Digital Breast Tomosynthesis images (DBT): LCC, LML, LMLO, RCC, RML, RMLO The following positioning example are tomo images stored as Digital Breast Tomosynthesis images (DBT) and Computed Tomography images (CT): LCC Use all the images to verify they are correcly displayed: orientation, hanging protocol Window Level and labels. The set contains 4 tomo LCC: DBT-LCC_CANOVA.dcm is a tomo in Digital Breast tomosynthesis format (DBT) and different Window Level values per frame. DBT_L_CC_CANOVA_SharedWL.dcm is a tomo in Digital Breast tomosynthesis format (DBT) and the same Window Level value for all the frames. CT-LCC_CANOVA is folder with a LCC tomo image in Computed Tomography format (CT) and different Window Level values per frame. CT_SharedWL-LCC_CANOVA is folder with a LCC tomo image in Computed Tomography format (CT) and the same Window Level value for all the frames. Different Window Level per frame id the Raffaello default setting. Shared Window Level for all the frames is an optional setting. All the frames of the LCC with Shared WL must be displayed with the following values: Window = 6803 Level = 1674 Test Images Page 9 of 10

10 The first frame of the LCC with Different WL per frame must be displayed with the following values: Window = 6737 Level = 1489 The last frame of the LCC with Different WL per frame must be displayed with the following values: Window = 6869 Level = 1859 Test Images Page 10 of 10