2013-08-05 26 views
3

我是新來處理DICOM圖像從他們的本土廠商的軟件了。我正在嘗試將一組重建的橫軸切片中的PET圖像分成MatLab。我的目標是做一些簡單的分割,並最終確定段中的最大和最小像素值。不過,我在將存儲的值轉換爲在本機系統上看到的值時遇到了問題。打開正電子發射斷層掃描(PET)在DICOM MATLAB的圖像和正確地解釋像素值?

的圖像被加載到MATLAB作爲INT16類。無論我從系列中加載哪個片,最大像素值始終爲32767。通過查看其本地系統上的圖像,我知道每個切片中的最大像素值是不同的。

我已經檢查重新調整值和重新調整截距值和重新調整的關係似乎是線性的。我應該做另一個更正嗎?我假設所有其他修正(例如衰減,分散和隨機)都是在重建過程中進行的。我發佈了下面標題中檢索到的DICOM信息(不要擔心,圖像是幻影,因此沒有患者識別數據)。

問候,

羅斯

        Filename: [1x76 char] 
          FileModDate: '26-Jul-2013 10:50:42' 
           FileSize: 38356 
           Format: 'DICOM' 
         FormatVersion: 3 
           Width: 128 
           Height: 128 
           BitDepth: 16 
          ColorType: 'grayscale' 
     FileMetaInformationGroupLength: 182 
      FileMetaInformationVersion: [2x1 uint8] 
       MediaStorageSOPClassUID: '1.2.840.10008.5.1.4.1.1.128' 
      MediaStorageSOPInstanceUID: [1x49 char] 
        TransferSyntaxUID: '1.2.840.10008.1.2.1' 
       ImplementationClassUID: '1.2.840.113619.6.55' 
      SourceApplicationEntityTitle: 'dst01' 
       IdentifyingGroupLength: 484 
        SpecificCharacterSet: 'ISO_IR 100' 
          ImageType: 'ORIGINAL\PRIMARY' 
        InstanceCreationDate: '20130522' 
        InstanceCreationTime: '171655' 
        InstanceCreatorUID: '1.2.840.113619.1.131' 
          SOPClassUID: '1.2.840.10008.5.1.4.1.1.128' 
         SOPInstanceUID: [1x49 char] 
          StudyDate: '20130514' 
          SeriesDate: '20130514' 
         AcquisitionDate: '20130514' 
          ContentDate: '20130522' 
          StudyTime: '142911' 
          SeriesTime: '143208.00' 
         AcquisitionTime: '143208.00' 
          ContentTime: '171655' 
         AccessionNumber: '' 
           Modality: 'PT' 
          Manufacturer: 'GE MEDICAL SYSTEMS' 
         InstitutionName: 'NHS TRUST' 
       ReferringPhysicianName: [1x1 struct] 
          StationName: 'dst01' 
         StudyDescription: '' 
        SeriesDescription: 'WB_3D_VuePoint' 
       PhysicianReadingStudy: [1x1 struct] 
          OperatorName: [1x1 struct] 
       ManufacturerModelName: 'Discovery STE' 
       Private_0009_GroupLength: 2714 
      Private_0009_10xx_Creator: 'GEMS_PETD_01' 
      Private_0009_11xx_Creator: 'GEMS_GENIE_1' 
        Private_0009_1002: 'SOLID_TEST' 
        Private_0009_1005: '20130514143030.00' 
        Private_0009_1006: 0 
        Private_0009_100a: [1x45 char] 
        Private_0009_100d: '20130514143208.00' 
        Private_0009_100e: '20130514143055.00' 
        Private_0009_1013: [1x59 char] 
        Private_0009_1014: 'Sternal Notch' 
        Private_0009_1015: 'SN' 
        Private_0009_1016: 0 
        Private_0009_1017: 0 
        Private_0009_1018: 0 
        Private_0009_1019: 0 
        Private_0009_101a: 1 
        Private_0009_101b: 0 
        Private_0009_101c: 1 
        Private_0009_101d: 0 
        Private_0009_101e: 1 
        Private_0009_101f: 1 
        Private_0009_1020: 0 
        Private_0009_1021: 1 
        Private_0009_1022: 0 
        Private_0009_1023: 0 
        Private_0009_1024: 2 
        Private_0009_1025: 2 
        Private_0009_1026: 23 
        Private_0009_1027: 1 
        Private_0009_1028: 1 
        Private_0009_1029: 0 
        Private_0009_102a: 0 
        Private_0009_102b: 70 
        Private_0009_102c: 153 
        Private_0009_102d: 0 
        Private_0009_102e: 0 
        Private_0009_1034: 0 
        Private_0009_1035: 0 
        Private_0009_1036: 'FDG -- fluorodeoxyglucose' 
        Private_0009_1037: '' 
        Private_0009_1038: 0 
        Private_0009_1039: '' 
        Private_0009_103a: 0 
        Private_0009_103b: '' 
        Private_0009_103c: 0 
        Private_0009_103d: '' 
        Private_0009_103e: '18F' 
        Private_0009_103f: 6588 
        Private_0009_1040: 0.9700 
        Private_0009_104d: 0 
        Private_0009_104e: 23 
        Private_0009_104f: 23 
        Private_0009_1050: 7 
        Private_0009_1051: 7 
        Private_0009_1052: 32 
        Private_0009_1053: 800 
        Private_0009_1054: 650 
        Private_0009_1055: 425 
        Private_0009_1056: [1x49 char] 
        Private_0009_1057: [1x48 char] 
        Private_0009_1059: [1x49 char] 
        Private_0009_105a: 0 
        Private_0009_105c: [1x49 char] 
        Private_0009_105d: [1x45 char] 
        Private_0009_105e: [1x51 char] 
        Private_0009_105f: 'SOLID_TEST' 
        Private_0009_1062: [1x44 char] 
        Private_0009_1063: 0 
        Private_0009_1064: 0 
        Private_0009_1066: 119.5000 
        Private_0009_1067: -79.8540 
        Private_0009_1068: '20130514143123.00' 
        Private_0009_1069: 553 
        Private_0009_106a: -79.9000 
        Private_0009_106b: 0 
        Private_0009_106c: '20130514143208.00' 
        Private_0009_106d: 180 
        Private_0009_1070: 0 
        Private_0009_1071: 90674329 
        Private_0009_1072: 0 
        Private_0009_1073: 1 
        Private_0009_1074: 255 
        Private_0009_107c: 0 
        Private_0009_107d: 2 
        Private_0009_107e: 0 
        Private_0009_107f: 0 
        Private_0009_1080: 0 
        Private_0009_1081: 0 
        Private_0009_108b: 5 
        Private_0009_108c: 2 
        Private_0009_108d: 0.0960 
        Private_0009_108e: 0 
        Private_0009_108f: 0 
        Private_0009_1090: 0 
        Private_0009_1091: 0 
        Private_0009_1092: 0 
        Private_0009_1093: 0 
        Private_0009_1094: 0 
        Private_0009_1095: 0 
        Private_0009_1096: [1x49 char] 
        Private_0009_1097: [1x51 char] 
        Private_0009_1098: [1x49 char] 
        Private_0009_1099: '' 
        Private_0009_109a: 0 
        Private_0009_109b: 0 
        Private_0009_109c: '' 
        Private_0009_109d: 0 
        Private_0009_109e: 0 
        Private_0009_109f: 0 
        Private_0009_10a0: 0 
        Private_0009_10a1: 0 
        Private_0009_10a2: 0 
        Private_0009_10a3: 0 
        Private_0009_10a6: 26 
        Private_0009_10a7: 0 
        Private_0009_10ab: 0 
        Private_0009_10ac: 0 
        Private_0009_10ad: '' 
        Private_0009_10ae: '' 
        Private_0009_10b2: 2 
        Private_0009_10b3: 20 
        Private_0009_10b4: 70 
        Private_0009_10b5: 0 
        Private_0009_10b6: 0 
        Private_0009_10b7: 0 
        Private_0009_10b8: 0 
        Private_0009_10b9: 0 
        Private_0009_10ba: 1 
        Private_0009_10bb: 6 
        Private_0009_10bc: 0 
        Private_0009_10bd: 0 
        Private_0009_10be: 0 
        Private_0009_10bf: 0 
        Private_0009_10c0: 0 
        Private_0009_10c1: 0 
        Private_0009_10c2: 0 
        Private_0009_10c3: 0 
        Private_0009_10c4: 6 
        Private_0009_10c5: 0 
        Private_0009_10c6: 0 
        Private_0009_10c7: 0 
        Private_0009_10cb: 0.8601 
        Private_0009_10cc: 0.1256 
        Private_0009_10cd: 0.8240 
        Private_0009_10ce: -0.0254 
        Private_0009_10cf: 0.5000 
        Private_0009_10d0: -0.0483 
        Private_0009_10d5: 0 
        Private_0009_10d6: 70.5000 
        Private_0009_10d7: -79.9000 
        Private_0009_10d8: 1 
        Private_0009_10db: 3 
        Private_0009_10dc: 2 
        Private_0009_10df: 47 
        Private_0009_10e2: 10 
        Private_0009_10e4: '3D_AC' 
        Private_0009_10e5: 0 
        Private_0009_10e6: 0 
        Private_0009_10e7: 0 
        Private_0009_10e9: 0 
        Private_0009_10ea: 0 
        Private_0009_10eb: 0 
        Private_0009_10ec: 0 
        Private_0009_111e: [1x49 char] 
        Private_0009_1146: [1x49 char] 
        PatientGroupLength: 96 
          PatientName: [1x1 struct] 
          PatientID: 'SOLID_TEST' 
         PatientBirthDate: '' 
          PatientSex: '' 
          PatientAge: '' 
          PatientSize: 0 
         PatientWeight: 0 
          EthnicGroup: '' 
       AdditionalPatientHistory: '' 
       Private_0017_GroupLength: 46 
      Private_0017_10xx_Creator: 'GEMS_PETD_01' 
        Private_0017_1004: '20130207140047.00' 
       AcquisitionGroupLength: 230 
         SliceThickness: 3.2700 
     AcquisitionTerminationCondition: 'TIME' 
      AcquisitionStartCondition: 'MANU' 
     AcquisitionStartConditionData: 0 
    AcquisitionTerminationConditionData: 0 
         SoftwareVersion: '41.04' 
          ProtocolName: 'WB 3D' 
          TriggerTime: 0 
          FrameTime: 0 
        IntervalsAcquired: 0 
        IntervalsRejected: 0 
       ReconstructionDiameter: 700 
        GantryDetectorTilt: 0 
         FieldOfViewShape: 'CYLINDRICAL RING' 
       FieldOfViewDimensions: [2x1 double] 
         CollimatorType: 'NONE' 
        ActualFrameDuration: 180000 
         PatientPosition: 'HFS' 
       Private_0019_GroupLength: 42 
      Private_0019_10xx_Creator: 'GEMS_PETD_01' 
        Private_0019_1004: '20130207140602' 
       RelationshipGroupLength: 322 
         StudyInstanceUID: [1x51 char] 
        SeriesInstanceUID: [1x49 char] 
           StudyID: '6893' 
          SeriesNumber: 401 
         InstanceNumber: 22 
        ImagePositionPatient: [3x1 double] 
       ImageOrientationPatient: [6x1 double] 
        FrameOfReferenceUID: [1x59 char] 
      PositionReferenceIndicator: 'SN' 
         SliceLocation: 1.8500 
      ImagePresentationGroupLength: 218 
         SamplesPerPixel: 1 
      PhotometricInterpretation: 'MONOCHROME2' 
            Rows: 128 
           Columns: 128 
          PixelSpacing: [2x1 double] 
         CorrectedImage: [1x40 char] 
         BitsAllocated: 16 
          BitsStored: 16 
           HighBit: 15 
        PixelRepresentation: 1 
       SmallestImagePixelValue: 0 
       LargestImagePixelValue: 32767 
         RescaleIntercept: 0 
          RescaleSlope: 0.3555 
       LossyImageCompression: '00' 
        Unknown_0040_0000: 158 
      AcquisitionContextSequence: [1x1 struct] 
     NuclearAcquisitionGroupLength: 808 
      EnergyWindowRangeSequence: [1x1 struct] 
RadiopharmaceuticalInformationSequence: [1x1 struct] 
         NumberOfSlices: 47 
        TypeOfDetectorMotion: 'NONE' 
     PatientOrientationCodeSequence: [1x1 struct] 
PatientOrientationModifierCodeSequence: [1x1 struct] 
PatientGantryRelationshipCodeSequence: [1x1 struct] 
          SeriesType: 'STATIC\IMAGE' 
           Units: 'BQML' 
          CountsSource: 'EMISSION' 
       RandomsCorrectionMethod: 'SING' 
      AttenuationCorrectionMethod: 'measured,, 0.096000 cm-1,' 
         DecayCorrection: 'START' 
        ReconstructionMethod: '3D IR' 
      DetectorLinesOfResponseUsed: '0' 
       ScatterCorrectionMethod: 'Model Based' 
          AxialMash: [2x1 double] 
         TransverseMash: 2 
       CoincidenceWindowWidth: 0 
        FrameReferenceTime: 0 
     PrimaryPromptsCountsAccumulated: 0 
      SecondaryCountsAccumulated: 0 
       SliceSensitivityFactor: 1 
          DecayFactor: 1.0095 
       DoseCalibrationFactor: 1139 
       ScatterFractionFactor: 0.3174 
         DeadTimeFactor: 1.1243 
          ImageIndex: 26 
        PixelDataGroupLength: 32780 

回答

1

我的乳房專用工作,沒有PET的經驗,所以要我說的話用少許鹽。

最大象素值是32767,其是2的15減1的功率是對重新調整斜率不是重要性?

RescaleSlope: 0.3555 

據推測,這可以改變針對每個切片的像素值應該由這個值(截距應當太加入但這是零)相乘。

+0

感謝medPhys-PL,這正是問題。我曾假定每個切片/研究的重新定標值都是固定的,並且僅取決於我們將數據轉換爲半定量值的校準。我很高興這很容易......我花了很長時間看着它,我錯過了明顯的。 – PercyP

1

在對各大廠商的掃描儀(西門子,GE,飛利浦)與通用電氣PET攝像頭工作時,我只遇到了片逐片RescaleSlope值。但是,檢查RescaleSlope和RescaleIntercept總是一個好主意。 QIBA FDG-PET工作組提供了一系列建議,並且還直接從DICOM數據中爲SUV計算僞碼。