医学成像与通信协议DICOM影像在各种显示介质上的一致性学术报告.ppt

Click to edit Master title style,*,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,The Grayscale Image Presentation Problem:,The appearance of grayscale images displayed on different types of softcopy display devices or printed on different types of hardcopy output devices has often been inconsistent.,Optimal image viewing parameters(e.g.window/level)selected on one device appear different when displayed on a different device,Device capabilities/characteristics vary-the same number of gray levels cannot be rendered or perceived on different devices,Displayed images look different from printed images,other,The Grayscale Consistency Problem:,Problems of Inconsistency,mass visible,mass invisible,VOI chosen on one display device,Rendered on another with different display,Mass expected to be seen is no longer seen,Slide Provided by David Clunie,Quintiles Intelligent Imaging,Problems of Inconsistency,Digital Modality,Laser Printer,Printed images dont looklike displayed images,Slide Provided by David Clunie,Quintiles Intelligent Imaging,Causes of Inconsistency,Gamut of device,Minimum/maximum luminance/density,Characteristic curve,Mapping digital input to luminance/density,Shape,Linearity,Ambient light or illumination,Causes of Inconsistency,1.0,.66,Display devicesvary in the maximumluminance they canproduce,Display CRT vs.film on a light box is an extreme example,Slide Provided by David Clunie,Quintiles Intelligent Imaging,Towards a Standard Display,Cant use absolute luminance since display capabilities different,Cant use relative luminance since shape of characteristic curves vary,Solution:exploit known characteristics of the contrast sensitivity of human visual system-contrast perception is different at different levels of luminance,Human Visual System,Model contrast sensitivity,assume a target similar to image features,confirm model with measurements,Bartens model,Grayscale Standard Display Function:,Input:Just Noticeable Differences(JNDs),Output:absolute luminance,Printer Calibration Tools(Densitometer),Display Calibration Tools(Photometer),Slide Provided by Jerry Gaskill,Image Smiths Inc.,Perceptual Linearization,.01,.1,1,10,100,1000,0,200,400,600,800,1000,Grayscale Standard Display Function,JND Index,Same number of Just Noticeable Difference=Same perceived contrast,Despite different change,in absolute luminance,Slide Provided by David Clunie,Quintiles Intelligent Imaging,Monitor Characteristic Curve,Monitor Characteristic Curve,0.01,0.1,10,100,0,50,100,150,200,250,300,Digital Driving Level,Ambient LightSlide Provided by David Clunie,Quintiles Intelligent Imaging,Standard Display Function,.01,.1,1,10,100,1000,0,200,400,600,800,1000,Grayscale Standard Display Function,JND Index,Monitors Capability,Jmax=P-Value of 2,n,-1,Jmin=P-Value of 0,Minimum Luminance,+Ambient Light,Maximum Luminance,+Ambient Light,Slide Provided by David Clunie,Quintiles Intelligent Imaging,Standardizing a Display,0.1,1,10,100,0,50,100,150,200,250,DDL or P-Values,Standard,Characteristic Curve,Slide Provided by David Clunie,Quintiles Intelligent Imaging,Standardizing a Display,Mapping P-Values to Input of Characteristic Curve(DDLs),0,50,100,150,200,250,300,0,50,100,150,200,250,300,P-Values,DDL,Slide Provided by David Clunie,Quintiles Intelligent Imaging,To Achieve Consistent Presentation of Images,the DICOM Standard Defines:,Basic Print Management with Presentation Look Up Table,for controlling the consistent appearance of preformatted images on printed output,Grayscale Softcopy Presentation State,for controlling the consistent appearance of images on softcopy display,Basic Print Management Meta SOP Class,Print(SCU),Print (SCP),Association Negotiation-“Contract Agreement”,Agreed set of SOP Classes and Transfer Syntaxes,(Basic Print Meta SOP Class),Film Sheet,Basic Print Meta SOP Class consist of four SOP Classes,(Film Session,Film Box,Image Box,and Printer),N-Create(create film sheet,format printer),N-Set(place images on film sheet),N-Action(request to print the film sheet),N-Event-Report(status of the printer),Slide Provided by Don Van Syckle,Merge Technologies Inc.,Example:A Radiologist“Flips”,Chest XRAY Image on Softcopy Display,Suspected,area,Example Continued:Radiologist Magnifies,Chest XRAY Image,Pans to Upper Right Hand Quadrant and Adds an Annotation,Referring Physician:,Radiologist:,Suspected,area,Example Continued:Referring Physician Views the Original Image,Radiologist Should Store the Viewing Parameters Using GSPS!,Composite object containing the image display settings parameters,Composite object links to one or more images(Series,filters);stored using same Study Instance UID(same Storage SOP Class!),Uses regular Storage services (C-STORE);uses Query/Retrieve services,GSPS SOP Instances are immutable:changes require a new SOP Instance UID,Note:generation and specific application of GSPS is outside the scope of DICOM,but not outside the scope of IHE(e.g.Virtual Image Set Split),Grayscale Softcopy Presentation State:,IE,Module,Usage,Patient,Patient,M,Study,General Study,M,Patient Study,U,Series,General Series,M,Presentation Series,M,Equipment,General Equipment,M,Presentation,Presentation State,M,Modality LUT,C-Required if to be applied,Mask,C-Required if multi-frame and to be applied,VOI LUT,C-Required if to be applied,Softcopy Presentation LUT,M,Graphic Annotation,C-Required if to be applied,Spatial Transformation,C-Required if rotation,flipping or magnification are to be applied,Displayed Area,M,Display Shutter,C-Required if to be applied and the Bitmap Display Shutter Module is not,present,Bitmap Display Shutter,C-Required if to be applied and the Display Shutter Module is not present,Overlay Plane,C-Required if to be applied or the BM,Displ.Shutter Module is present,Overlay/Curve Activation,C-Required if image contains curve or overlay which is to be displayed,Graphic Layer,C-Required if Graphic Annotation or Overlays or Curves are to be applied,SOP Common,M,GSPS Module Table:,DICOM Grayscale Image Transformation Model,e,T,r,a,n,s,f,o,r,m,a,t,i,o,n,V,O,I,L,U,T,(,S,u,b,t,r,a,c,t,i,o,n,),M,a,s,k,M,o,d,a,l,i,t,y,L,U,T,T,r,a,n,s,f,o,r,m,a,t,i,o,n,A,n,n,o,t,a,t,i,o,n,I,m,a,g,e,T,r,a,n,s,f,o,r,m,a,t,i,o,n,S,h,u,t,t,e,r,S,p,a,t,i,a,l,T,r,a,n,s,f,o,r,m,a,t,i,o,n,A,n,n,o,t,a,t,i,o,n,D,i,s,p,.,A,r,e,a,Presentation,LUT,Presentation,LUT,Transformation,Window/Level,or VOI LUT,Rescale Slope/Intercept,or Modality LUT,Original,Image,Display,P-Values,Grayscale Transformations,Shutter,Annotation and Spatial Transformations,What about color?,Consistency is harder to achieve,Not just colorimetry(i.e.not just CIELAB),Gamut of devices much more variable,Greater influence of psychovisual effects,Extensive standards efforts e.g.ICC,DICOM is defining color presentation in a manner very similar to grayscale,but utilizing the ICC profiles instead of the GSDF,see Supplement 100.,Many display and print devices already have ICC profiles,but few medical imaging devices support color presentation state.,Consistent Presentation is Provided by,Use of DICOM GSDF for calibration of monitors,Use of Presentation LUT for Grayscale Print,Creation of GSPS SOP Instances to capture the presentation of softcopy images.,Use of GSPS SOP Instances when displaying images from archives,(Devices that claim conformance to IHE Consistent Presentation of Imagesprovide these functions.),