(Digital Imaging and COmmunictions in Medicine) -디지털정보융합학과- 홍각표 DICOM (Digital Imaging and COmmunictions in Medicine) -디지털정보융합학과- 홍각표

0. Index Introduction General DICOM Concepts DICOM Network DICOM Service Class DICOM Image SOP Instance New Feature of DICOM

1. Introduction 1.1 DICOM 이란 ? DICOM : Digital Imaging and COmmunictions in Medicine Committee formed to develop a standard for imaging equipment to communicate with other devices. Both an image format & a network protocol. (As you might be able to guess from the “Imaging” and “Communications” parts of the name) 3

1. Introduction 1.2 Brought To You By, Origins ACR: American College of Radiology NEMA: National Electrical Manufacturers Association AAPM: American Association of Physicists in Medicine RSNA: Radiological Society of North America ACR & NEMA formed a committee in ’83 Inspired by AAPM’s format for writing images to tapes Released “ACR/NEMA” precursor in 1985 and “ACR/NEMA V2.0” in 1988 Version 3 in 1993 improved network support and changed the name to DICOM DICOM is still version 3 and has been updated regularly since 4

1. Introduction 1.2 DICOM File 과 일반 영상 File의 차이점 BMP File(bmp)은 오직 영상자체의 정보만 있다 Bitmap 파일 DICOM File(dcm)은 영상자체의 정보 및 영상에 관련된 모든 정보를 가지고 있다. 영상파일 + 환자이름, 촬영날짜, 촬영장비 DICOM File 5

1. Introduction 1.3 DICOM의 필요성 각 영상 장비간의 상호 연동을 위한 표준화 How? 6 DICOM Modalities Viewing System 3개의 Modalities에 3개의 Viewing System 필요 3개의 Modalities에 1개의 Viewing System만 필요 How? 각 영상 장비간의 상호 연동을 위한 표준화 6

1. Introduction 1.4 통신 protocol 표준화 DICOM Modalities Viewing System Digital Archive Printer CD Writer Connection to Other Network DICOM (Network) 7

2. DICOM 2.1.1 Information Object Definition Information Object Information Entities Modules Attributes MR Image 검사정보 일자 2013.3.26 장비종류 A사 CT 촬영부위 Brain 환자정보 나이 30세 체중 75Kg 이름 홍길동 8

2. DICOM Unique Attribute Name (human readable) 2.1.2 Attributes Unique Attribute Name (human readable) Unique Attribute Tag (information system readable) Attribute Description (semantics) Type classification : 1, 1C, 2, 2C, 3 9

2. DICOM 2.1.3 DICOM Service Element (DIMSE) - DIMSE는 IOD를 가지고 할 수 있는 모든 행위 C-Service : Image와 같이 복합된 정보를가지고 있는 것의 행위 N-Service : 단일한 정보만을 가지고 있는 것에 대한 행위 명령 Services 저장하라 C-Store 찾아라 C-Find 전송하라 C-Move 만들어라 N-Set 가져와라 N-Get . 10

2. DICOM 2.1.4 SOP class - 무엇을(IOD) + 어떻게(DIMSE) IOD DIMSE SOP Class CT Image C-Store Store CT Image MR Image C-Find Find MR Image 11

2. DICOM 2.1.5 DICOM Information Model 12

2. DICOM 2.1.6 Unique Identification(UID) MR Image SOP Class UID 1.2.840.10008.5.1.4.1.1.4 JPEG2000 Image compression UID 1.2.840.10008.1.2.4.91 UID = <root>.<suffix> = <1.2.840.10008>.<5.1.4.1.1.4> 13

2. DICOM 2.1.7 Value Representation(VR) VR Name AE Application Entity OW Other word string AS Age String PN Person Name AT Attribute Tag SH Short string CS Code String SL Signed Long DS Decimal string SQ Sequence of Item DA Date SS Signed Short DT Date Time ST Short Text FL Floating point single TM Time FD Floating point double UI Unique Identifier IS Integer string UL Unsigned Long LO Long String UN Unknown LT Long Text US Unsigned Short Other Byte String 14

2. DICOM - byte ordering - 압축의 유무 - 압축방식 2.1.8 Transfer Syntax Transfer Syntax of DICOM의 예  Implicit Little Endian , Explicit Little Endian, Explicit Big Endian, DICOM JPEG DICOM JPEG2000 15

2. DICOM 2.1.9.1 DICOM Data Format element Tag VR Value Length Value Field Data set Order of transmission Data element Optional field (예) Tag (0028,0101) Bits Stored , Length 2 (00000002), Value  8 (0008) 28 00 01 02 08 Tag Length Value 16

2. DICOM 2.1.9.2 DICOM Data Format 128byte다음의 4byte가 “DICM” => DICOM File 17

2. DICOM 2.1.10. DICOM File Examples 128 Byte Preamble + File Meta Header (0x0002 그룹 속성들) + Data Set Transfer Syntax를 명시적으로 지정 18

2.2. DICOM Network 2.2.1. 용어 Application Entity(AE) : “DICOM 통신을 할 수 있는 것의 이름” Presentation Context (PC) : “어떤것은 어떤 방식으로 처리할 것인지에 대한 것을 표현” Abstract Syntax Transfer Syntax Presentation Context 사용되는 SOP class Encoding 방식 (저장방식) Abstract Syntax + Transfer Syntax MR Image를 저장하라 JPEG 압축 JPEG으로 압축된 MR Image를 저장하라 19

2.2. DICOM Network 2.2.2. DICOM Network Model 20 LLC ISO NETWORK ISO TRANSPORT ISO SESSION KERNEL ISO PRESENTATION ISO Association Control Service Element (ACSE) TCP IP DICOM Upper layer protocol for TCP/IP Ethernet, FDDI, ISDN, etc. DICOM Application Entity Medical Imaging Application ISO Upper Layer Service boundary 20

2.2. DICOM Network 2.2.3. Association Negotiation 21

Conformance Statement 비교 2.2. DICOM Network 2.2.4. Service Class User (SCU), Service Class Provider(SCP), Conformance Statement DICOM Storage SCP / SCU SCP SCU 연동 가능한가 ? Conformance Statement 비교 HOW ? Modality A Modality B A의Conformance Statement B의 Conformance Statement 22

2.2. DICOM Network 2.2.5. Conformance Statement 23

4. DICOM file format 4.1 Review DICOM DATA format Data set Order of transmission Preamble (128Bye) DICM (4) Data element Data element Data element Data element Data element Tag (4) VR (2) Value Length (4) Value Field (n byte) Optional field (예) Tag (0028,0101) Bits Stored , Length 2 (00000002), Value  8 (0008) 28 00 01 02 08 Tag Length Value 24

128byte 4. DICOM file format 4.2 Preamble and “DICM” Preamble(128byte) : 특별한 사용이나, application profile 로 이용                byte[] preamble = new byte[132];             br.Read(preamble, 0, 132);             if (preamble[128] != 'D' || preamble[129] != 'I' || preamble[130] != 'C' || preamble[131] != 'M')             {                   throw new Exception("Not a valid dicom file");                                } ------------------------------------- while(1) { if( field->group == 0x7fe0 && field->item == 0x0010 ) break; ---------------------------------------- Case 0030: memcpy(field1.birth, &pData[count+8],field->length); break; }            DICM : 대상파일이 DICOM 인지 아닌지? 128byte DICM 25

4. DICOM file format 4.3. Size에 제한이 있는 VR 26

Attribute Description 4. DICOM file format 4.4. DICOM image - Patient Attribute Name Tag Attribute Description Patient's Name (0010,0010) Patient's full name. Patient ID (0010,0020) Primary hospital identification number or code for the patient. Patient's Birth Date (0010,0030) Birth date of the patient. Patient's Sex (0010,0040) Sex of the named patient. Enumerated Values:             M = male             F = female             O = other 27

4. DICOM file format 4.5. DICOM image - Study Attribute Name Tag Attribute Description Study Instance UID (0020,000D) Unique identifier for the Study. Study Date (0008,0020) Date the Study started. Study Time (0008,0030) Time the Study started. Referring Physician's Name (0008,0090) Name of the patient's referring physician Study ID (0020,0010) User or equipment generated Study identifier. Accession Number (0008,0050) A RIS generated number that identifies the order for the Study. 28

4. DICOM file format 4.6. DICOM image - Modality Modality (0008,0060) Name Tag Attribute Description Modality (0008,0060) Type of equipment that originally acquired the data used to create the images in this Series. See C.7.3.1.1.1 for Defined Terms. Series Instance UID (0020,000E) Unique identifier of the Series. Series Number (0020,0011) A number that identifies this Series. Laterality (0020,0060) Laterality of (paired) body part examined. Required if the body part examined is a paired structure and Image Laterality (0020,0062) or Frame Laterality (0020,9072) are not sent. Enumerated Values:             R = right             L = left Note:        Some IODs support Image Laterality (0020,0062) at the Image level or Frame Laterality(0020,9072) at the Frame level in the Frame Anatomy functional group macro, which can provide a more comprehensive mechanism for specifying the laterality of the body part(s) being examined. 29

4. DICOM file format 4.6. DICOM image - Modality Instance Number Name Tag Attribute Description Instance Number (0020,0013) A number that identifies this image. Note:        This Attribute was named Image Number in earlier versions of this Standard. Patient Orientation (0020,0020) Patient direction of the rows and columns of the image. Required if image does not require Image Orientation (Patient) (0020,0037) and Image Position (Patient) (0020,0032). Content Date (0008,0023) The date the image pixel data creation started. Required if image is part of a series in which the images are temporally related. Note:        This Attribute was formerly known as Image Date. Content Time (0008,0033) The time the image pixel data creation started. Required if image is part of a series in which the images are temporally related. 30

4. DICOM file format 4.7. DICOM image - pixel 31 Attribute Name Tag Attribute Description Samples per Pixel (0028,0002) Number of samples (planes) in this image. Photometric Interpretation (0028,0004) Specifies the intended interpretation of the pixel data. Rows (0028,0010) Number of rows in the image. Columns (0028,0011) Number of columns in the image Bits Allocated (0028,0100) Number of bits allocated for each pixel sample. Each sample shall have the same number of bits allocated. Bits Stored (0028,0101) Number of bits stored for each pixel sample. High Bit (0028,0102) Most significant bit for pixel sample data. Pixel Representation (0028,0103) Data representation of the pixel samples. Each sample shall have the same pixel representation. Enumerated Values:             0000H = unsigned integer.             0001H = 2's complement Pixel Data (7FE0,0010) A data stream of the pixel samples that comprise the Image Required if Pixel Data Provider URL (0028,7FE0) is not present. Planar Configuration (0028,0006) Indicates whether the pixel data are sent color-by-plane or color-by-pixel. Required if Samples per Pixel (0028,0002) has a value greater than 1. See C.7.6.3.1.3 for further explanation. 31

Attribute Description 4. DICOM file format 4.8. DICOM image – SOP common modules Attribute Name Tag Attribute Description SOP Class UID (0008,0016) Uniquely identifies the SOP Class. // The SOP Class UID of // SC Image is e.Init((int)DICOM_TAGS_ENUM.sopClassUid); e.Value = "1.2.840.10008.5.1.4.1.1.7"; o.insertElement(e); SOP Instance UID (0008,0018) Uniquely identifies the SOP Instance. // We've instanciated a DCXUID // above. Let's use it again // to create a SOP Instance UID e.Init((int)DICOM_TAGS_ENUM.sopInstanceUID); e.Value = uid.CreateUID(UID_TYPE.UID_TYPE_INSTANCE); 32

5.DICOM Service Class Storage Service Class Query/Retrieve Service Class Modality Worklist Management Basic Worklist Management Modality Performed Procedure Step (MPPS) Storage Commitement Media Exchange 33

5.DICOM Service Class 영상을 주고 받을때 사용하는 Sevice Class 5.2 Storage Service Class 영상을 주고 받을때 사용하는 Sevice Class 모든 종류의 영상 및 형태에 대해 SOP Class UID 가 정의 34

5.DICOM Service Class 영상을 검색하고 조회할 때 사용하는 기능 5.3 Query/Retrieve Service Class 영상을 검색하고 조회할 때 사용하는 기능 서로 다른 업체의 장비간의 표준화된 검색 방식 정의 Query : 검색 할 때 사용 Retrieve : 검색후 필요한 영상을 가져올 때 사용. 35

5.DICOM Service Class 영상장비간 통신을 하기 위한 것이 아니라 OCS 와 연동하기 위한 서비스 5.4 Modality Worklist Management 영상장비간 통신을 하기 위한 것이 아니라 OCS 와 연동하기 위한 서비스 환자 및 검사정보를 촬영자가 수작업으로 입력해야 하는 번거로움과 오류입력 해결 Request Worklist Worklist Entries Modality Worklist(SCU) Modality Worklist(SCP) BASIC WORKLIST MANAGEMENT SERVICE : 장비에서 촬영을 위해 필요로 하는 환자 및 검사정보를 제공 - MODALITY PERFORMED PROCEDURE STEP : 장비에서의 촬영 진행 상황을 나타내기 위한 것 SOP CLASS NAME SOP CLASS UID Modality Worklist Information Model – FIND 1.2.840.10008.5.1.4.31 Modality Performed Procedure Step 1.2.840.10008.3.1.2.3.3 36

5.DICOM Service Class 5.4.1 Basic Worklist Management 검사장비에서 수행되어야 할 작업 목록 Matching Key : 검사조건 / Returnkey : 결과정보 Ex) 오늘의 촬영 날짜와 검사 장비의 종류에 대한 조건을 Matching Key로 보내고 그에 해당하는 검사대상 환자의 정보를 Returnkey로 얻어온다. Modality Worklist 의 실제 과정 1. 검사 요청이 있었던 환자에 대한 정보를 검사 장비 Worklist SCU 가 C-FIND-RQ 요청을 통해 SCP 에 요구 2. C-FIND-RQ 시 이 Modality Worklist Information Model 안에 질의에 대한 조건이 들어가고 3. 장비와 DICOM 통신을 하는 Worklist SCP는 다시 C-FIND-RSP 답신을 통해 요청된 질의에 대한 결과를 이 Modality Worklist Information에 담아 돌려 보냄. DIMSE Service Element C-FIND-RQ C-FIND-RSP * Worklist SOP Class 는 DICOM에서 C-FIND DIMSE 명령과 Modality Worklist Information Model 정보객체의 결합을 통해 이루어짐 37

5.DICOM Service Class 5.4.2 Modality Performed Procedure Step(MPPS) 장비에 기본적인 환자 및 검사정보가 제공 되어지면 촬영의 시작, 진행 및 종료의 과정을 거치게 되는데 MPPS는 이러한 촬영의 진행과정을 DICOM message의 형태로 보냄으로써 쉽게 진행 상태를 알 수 있도록 함. DIMSE Service Element Usage SCU/SCP N-CREATE M/M N-SET 38

5.DICOM Service Class 5.5 Storage Commitment DICOM Worklist와 더불어 최근 생산되는 장비에는 거의 기본적으로 탑재 C-Store Operation N-ACTION-list of reference Image of UIDs Storage Commitment(SCU) Storage Commitment(SCP) N-EVENT-(Success or Fail) 이러한 기능을 제공하기 위하여 아래와 같은 SOP Class를 제공 39

5.DICOM Service Class 5.6 Media Exchange Media Exchange라는 것은 의료영상을 네트워크가 아니라 CD 나 MOD, DVD와 같은 저장매체를 통해 영상을 전달할 때에 어떻게 해야 하는지를 규정 DICOM 방식으로 구운 CD를 보통 DICOM CDR이라고 부르는데, 이 CD에는 반드시 DICOMDIR 이라고 하는 디렉토리 파일이 들어있어야 하며 이는 그 CD안에 들어있는 내용의 목차가 저장되어 있는 파일 40

5.DICOM Service Class 5.6 Media Exchange 41

5.DICOM Service Class 5.8 Print Management Model SOP Class SOP Class UID Reference Basic Grayscales Print Management SOP Class 1.2.840.10008.5.1.1.9 2.1 Basic Color Print 1.2.840.10008.5.1.1.18 2.2 Pull Stored Print 1.2.840.10008.5.1.1.32 2.3 42

6. Image Information Model 각 환자(Patient) 당 여러 개의 검사(Study), Series 및 Image가 발생 Patient, Study, Series, Image는 1 : n의 포함 관계 43

5.DICOM Service Class 6.2 Image Types Image Information은 각자의 역할에 따라 Patient Information, Study Information, Series Information, Application Information 등으로 나누어짐. Identification Attribute SOP Class UID, Study Instance UID, Series Instance UID, Image Instance UID(=SOP Instance UID) 등 Modality Type Pixel Value Interpretation Photometric Interpretation 등 Pixel Encoding Bit Allocated, Bit Stored, High Bit, Pixel Representation, Planar Configuration 등 Pixel Matrix Pixel Data 44

5.DICOM Service Class 6.3. SOP instance UID 45

감사합니다. 46