DICOM. image protocol

Transcription

1 Chin J Radiol 2002; 27: , Digital Image Communications in Medicine standard IT domain medical domain [1] CR image 1994 CT MR digital NEMA 1994 [2] Digital Image Communications in Medicine format transmission protocol basic requirement [3] header pixel data header Fig 1 group module group patient module study module series module image module pixel data rendering, display

2 232 Tag versus image Fig 2a X Fig 2a flattening display Doppler velocity Scaling Scaling US Region Calibration Module US FDA Fig 2a digital radiography [3,7] non-linear transformation VOI LUT SEQ Fig 3a, 3b US VOI LUT SEQ digitized image grabbing pixel calibration 2a 2b VOILUT SQ X VOILUT SQ flattening

3 Tag versus image 233 3a 3b 3a 3b Scaling System US Region Calibration Module Region Calibration Module ROI region of interest distance measurement cursor spectrum waveform Doppler velocity s data set Part 6 Part 6 data dictionary [5] [4] Fig 1 TAG3 VR, Value Length, Value Field. TAG gggg eeee g group e element HEXA 16 0,1,2,3 9, A... F, Patient Name TAG 0008,103E series description TAG Tag Header VR value representation 0010, 0010 = Patient Name VR = PN gggg eeee VR=PN VR = DA date VR =TM time VR =UI UID UID VR option transfer syntax explicit VR implicit Value length Value field Value Field I.O.D. [3] I.O.D. information Object Definition A data abstraction of a class of similar Real-World Objects which defines the nature and Attributes relevant to the class of Real-World Objects represented. I.O.D. instance Instance CT class image or.

4 234 Tag versus image CT I.O.D. Fig 4 header Tags 0008, 0060 modality (0008, 0068 presentation intent type s value field FOR PRESENTATION display or browse X 0008, 0068 FOR PROCESS 0008, , , 1080 value filed worklist VOI LUT Sequence 0008, 0068 for presentation VOI LUT Sequence LUT look up table VOI value of interest Sequence VOI LUT Sequence root element child data elements LUT Descriptor LUT Explanation LUT Data LUT Data pixel data luminance Fig 5a standalone LUT I.O.D. VOI LUT SEQ linear transformation Fig 5b LUT data non-linear transformation Fig 5c LUT data GAMMA correction soft copy presentation state storage Image browser, TAG Browser X header Data elements 0018, 6011 tags content item content item Region location Min x0 Min y0 Max x1 Max y1 value file calibration module Fig 6 Items physical units X, Y direction X, Y Fig , , cm 4 seconds physical delta X, Y X, Y pixel US region calibration module Scaling auto-calibration s PACS Scaling US Region Calibration Module Sequence of Ultrasound Regions 0018, 6011 SQ tag Sequence [8, 9] tag tag SQ tag smart tag tag one dimension nested structure Sequence of Ultrasound Regions UID unique identifier UID Presentation Context [6] nodes Association Presentation Context Presentation Context syntax Abstract Syntax Transfer Syntax Abstract Syntax Storage service class Study management service class Digital X-Ray Image Storage For Presentation UID

5 Tag versus image 235 Output=RSxPixel + RI Max Rescale Type Range Rescale Slope Rescale Intercept Max Storad Pixel Value Range 5a 5b Modality LUT VOI LUT Y[n]=F[Start Value + n-1] Output Y Range [ ] Start Value N Number of Entries 5a standalone LUT I.O.D. LUT data 5b linear transformation 5c non-linear transformation 5c Transfer Syntax encoding big endian or little endian explicit or implicit lossless or lossy Little Endian Implicit association nodes transfer syntax storage or management UID unique identifier TAG Browser header Calibration Module US US Region : Implicit VR Little Endian Transfer Syntax. L.E.I. 1 identifies ISO 2 is the ISO member body branch ISO 840 is the specific member body country code in this case ANSI ISO is registered by ANSI to NEMA for ANSI Abstract Syntax Transfer Syntax UIDs ISO

6 236 Tag versus image NEMA ANSI USA ANSI Image unique identifier UID PACS SECURE TRANSPORT CONNECTION PROFILES SOP Instance Status 0100, 0410 [10] tag Fig 7 SOP Instance Status 0100,0410 AC authorized copy original supplements Tag OR original or AC authorized 1999, 2000, 2001 value = OR original Network AO authorized original Network delete modality (server OR /AO NS non-specified or AC authorized copy SOP Instance Status OR /AO delete retrieve SOP Instance Status NS/AC 1. Siegel, E. L. PACS: current technology, clinical requirements, and future trends, Maryland Univ. Med. Sch., Baltimore, MD, USA, Proceedings of the 4th International Conference on Image Management and Communication IMAC '95 2. standard, Part 1: Introduction and Overview published by National Electrical Manufacturers Association 3. standard, Part 3: Information Object Definitions published by National Electrical Manufacturers Association 4. standard, Part 5: Data Structures and Encoding published by National Electrical Manufacturers Association 5. standard, Part 6: Data Dictionary published by National Electrical Manufacturers Association 6. standard, Part 7: Message Exchange published by National Electrical Manufacturers Association 7. standard, Supp 32, Digital X-Ray, published by National Electrical Manufacturers Association 8. standard, Supp 23, Structured Reporting Object, published by National Electrical Manufacturers Association 9. David Clunie. Structured Report, ISBN standard, Part 15: Security Profiles published by National Electrical Manufacturers Association copy SOP Instance Status 0100,0410 original non-specified

7 Tag versus image 237 From TAG to Digital Medical Image TSUNG LUNG YANG Department of Radiology, Kaohsiung-Veterans General Hospital Picture Archiving and Communication System (PACS) is the main innovative trend for medical industry of the new 21st century. Through the introduction of basic elements and structure of digital medical image, the readers will be expected to understand how the (Digital Image Communications in Medicine) standard works on the digital medical image. With the disclosure of key essence of data elements and Tags, which form the content of every digital medial image, it is hoped that the gap between IT domain and medical domain will be shortened in order to promote the PACS industry in Taiwan. Key words: PACS,, TAG