The present invention pertains to the image display arts. It finds particular application in conjunction with the display and review of CT medical diagnostic images on video monitors and will be described with particular reference thereto. However, it is to be appreciated that the invention is also applicable to the display and review of medical diagnostic images derived or generated from magnetic resonance, nuclear, and other imaging modalities, to quality assurance and other 3-dimensional, non-medical images, and the like. The invention is also applicable to hard copy displays, film image displays, and other display formats.
Heretofore, CT scanners have irradiated regions of a subject from various angles and detected the intensity of radiation passing therethrough. For 3-dimensional imaging, the patient was moved along a longitudinal axis of the CT scanner either continuously for spiral scanning or incrementally, to generate a multiplicity of slices. The image data were reconstructed and extrapolated or interpolated as necessary, to generate CT numbers corresponding to each of a 3-dimensional array of voxels. For simplicity of illustration, each of the CT numbers can be conceptualized as being addressable by its coordinate location along three orthogonal axes, e.g. x, y, and z-axes of the examined volume.
Typically, the image volume data set is stored in a memory device for communication and/or retrieval at a later date. This enables a convenient review of the patient images by radiologists or clinicians on a workstation or similar PC type system. Various planar representations of the image volume data set are now commonly available to radiologists using the workstation. Most commonly, the examined volume is a 6-sided prism or polyhedron with square or rectangular faces. The radiologist uses a pointing device such as a mouse to select a view depicting any one of the six faces of the prism or any one of the slices through an interior of the prism along any of the (x, y), (x, z) or (y, z) planes. Some display formats also permit oblique or curved planes to be selected. Display formats are also available which permit two or three sides of the prism to be displayed concurrently on a 2-dimensional (i, j) image plane with appropriate visual cues to give the impression of a perspective view in three dimensions.
When radiologists review a patient image volume data set, the traditional approach is to review the images in a sequential manner, e.g. review axial slices cranial to caudal, one image slice at a time in a fixed order on a page montage of images. However, an increased number of radiologists are reviewing patient cases on workstations and viewing stations rather than viewing the traditional image films. At these workstations, the radiologists typically cause a selected surface, such as a transverse (x, y) plane on the face (z=0) of the examined volume to be displayed. The radiologists could then cause a selected number of transverse planar slices to be ?peeled? away or deleted by indexing along the z-axis (z=1, 2, . . . Zmax) to view the interior transverse planes. The radiologists could then position the cursor on the (x, y) or transverse plane to select a coronal or (x, z) plane. The selected coronal plane would then be displayed. The operator would then position the cursor on the displayed coronal plane and select a sagittal or (y, z) plane. Current medical image workstations commonly permit the transverse, coronal, or sagittal sections or views to be displayed concurrently in different view ports on the same screen.
Clearly, reviewing the patient image data set case on a computer workstation affords a great deal of flexibility in the review process. Viewing techniques for large image volumes currently available in medical imagers such as MD-CT devices with high temporal-spatial resolution may include cine, montage paging, slabs with variable thickness, and oblique multi-planar reformatting (MPR). Such search methods may have sequential or non-sequential navigation or may include gestaltian methodologies. These workstations have the ability to provide radiologists with large amounts of information in a small amount of time. Particularly, the user may cine through the image data in a ?back and forth? fashion along arbitrary paths, skip around the image volume, switching between sequential and problem solving search paradigms, review supplementary aspects of the volume in various selected MPR planes, review a suspicious area at a higher resolution and other areas at a lower resolution, or suspend the patient case review and return thereto at a later date or time.
One disadvantage of the prior art display systems described above, however, is that it is difficult for radiologists to keep track of which aspect(s) of the patient image volume have been reviewed carefully and which portions have not. Although the radiologists have full control over how images are displayed on the screen, without proceeding through the case study sequentially, it is difficult to record or categorize portions of the image volume previously studied.
One solution is the use of redundant reading. However, this costs time and is therefore wasteful. Further, the redundant reading technique does not guarantee that all relevant portions of the image volume are read. Also, in another solution, radiologists might maintain a mental checklist of those solid organs which have been reviewed and those which have not. As an example, in the abdomen, the review sequence might include a review of the liver first, followed by kidneys, spleen, and so forth. However, this strategy is not particularly effective in the chest, for instance, as there may be one or more large areas of the lung parachyma that need to be reviewed and the sub-volumes are less delineated by discreet anatomical objects. In this case, the radiologist can simply become ?lost? within an organ image.
The present invention contemplates new and improved apparatus and graphical methods for tracking image volume review which permit the review of patient studies on workstations without the risk of inadvertent omission of a review of critical portions of the patient image volume. The device and methods disclosed herein provide graphical feedback during the review process and in correlation with the anatomical image volume as to which aspects of the image volume have been reviewed. This enables the radiologists to search through the data set as desired and substantially unscripted because the improved apparatus and methods disclosed herein provide feedback to the radiologists to ensure that all aspects of the image volume are evenly reviewed or studied without redundant reading.
The subject invention provides graphical feedback identifying those aspects of the image volume which have been reviewed, the detailed focus of that review including information relating to an amount of time which has been spent on each portion of the volume, and which aspects have been skipped or under-reviewed. This information is presented in a separate display viewport using a ?completion cube? or ?completion sphere? graphical format. As the radiologist displays images at the workstation, the completion cube is updated in the separate display viewport to indicate those aspects of the data set which have been reviewed and at what level of detail. A transform is provided to uniquely map the image volume to the completion cube. As portions of the image volume are displayed for review by a radiologist, the projections to the cube are automatically shaded or colorized as a function of the level of detail and/or time the image was displayed in accordance with a shading function. Mappings for various image reviews are described, for example axial, axial followed by coronal, oblique MPR, volume projections, and cine. The shading function can also be combined with image data on a projection or on an axial/sagittal/coronal base. The shaded cube is displayed simultaneously with the display of the patient image volume during the study. Data forming the cube can be achieved to memorialize the study or for retrieval at a later date.
In accordance with one aspect of the invention, a method of clinical review of images of patients includes providing an image volume data set of an anatomical structure. A plurality of selectable portions of the image volume data set are displayed on a human readable display device. Data identifying each of the plurality of selectable portions displayed on the human readable display is stored as a record of those portions of the anatomical structure studied by the radiologist. Preferably, the data identifying each of the plurality of selectable portions displayed on the human readable display device includes information relating to aspects of the data set which have been reviewed and data indicating the level of detail of review.
In accordance with a further aspect of the invention, a method of clinical review of images of patients includes generating an image volume data set of the patient on a scanner device and storing the image volume data set in a memory of the scanner device. A first portion of the image volume data set is selected using input means of the associated scanner device. The first portion of the image volume data set is displayed as a first image of the patient on a human readable display of the scanner device. The first portion of the image volume data set displayed is mapped to a first portion of a volume completion data set. The volume completion data set is displayed as a completion cube image with the first portion of the volume completion data set of the completion cube identified according to a predetermined colorization function to visually differentiate the first portion of the volume completion data set from the remaining portion of the volume completion set.
In accordance with yet a further aspect of the invention, a method of clinical review of images of patients includes generating multiple image volume data sets of the patient using gating means in a scanner device triggered according to selected points in multi-phase studies such as liver and cardiac investigations. The image volume data sets are displayed individually on a display device simultaneously with a completion cube identifying portions of the volume image studied by radiologists. As an example, a volume completion cube is displayed corresponding to each image volume data set collected during heart cycles triggered during various phases thereof such as during ventricular contraction. As each phase is investigated, the completion cube is colorized to confirm that the particular phase was investigated or displayed.
One advantage of the present invention is that it provides radiologists with the ability to review image volumes of patients while tracking aspects of the image volume that have been reviewed carefully and which have not.
Another advantage of the invention is that it provides radiologists with the ability to suspend the review of patient image volume data sets as desired or necessary and then resume those reviews at a later time or date without the concern of overlooking portions of the image volume and without the potential waste of duplicated efforts due to redundant review.
Still other advantages and benefits of the invention will become apparent to those skilled in the art upon a reading and understanding of the following detailed description.
The invention may take physical form in certain parts and arrangements of parts, the preferred embodiments of which will be described in detail in the specification and illustrated in the accompanying drawings which form a part hereof, and wherein:
a and 4b are views of a volume image display and a completion cube display presented to a radiologist in accordance with the invention;
a and 5b show examples of the completion cube image presented to a radiologist during a patient image study;
a and 6b show examples of the completion cube displayed following axial/coronal reviews and after an oblique MPR review of the patient image, respectively;
a and 10b illustrate alternative embodiments including a spherical completion cube representation and a projection completion cube representation.
Referring now to the drawings wherein the showings are for the purposes of illustrating the preferred embodiment of the invention only and not for purposes of limiting same, with reference first to
The scanning device 12 is preferably, a CT volumetric diagnostic imaging apparatus 20 is disposed in axial alignment with the patient table such that a patient or subject on the patient support surface 16 can be moved into and through a bore 22 of the volumetric imager. In the illustrated embodiment, the volumetric imager is a CT scanner which includes an x-ray tube mounted for repeated circular travel within a preselected plane. The x-ray tube projects a fan-shaped beam of radiation through a ring 24 of radiation translucent material, through the patient support 16, through a region of interest of the subject, and to a ring or arc of radiation detectors positioned opposite the x-ray tube. As the x-ray tube rotates within the plane, a series of data lines are generated, which data lines are reconstructed into at least a slice image by a reconstruction processor included in a control console 26 of the workstation 12. The control console is typically remotely located in a shielded room adjacent the scan room containing the imaging apparatus 10. More specifically to the preferred embodiment, the patient support 16 moves longitudinally as the x-ray tube is rotating around the subject such that a selected volume of the patient is scanned along a spiral path or a series of slices. The position of the x-ray tube is monitored by a rotational position encoder, and the longitudinal position of the patient support is monitored by a longitudinal position encoder within the table 14. The reconstruction processor reconstructs a volumetric image representation from the generated data lines. The control console 26 typically includes one or more monitors 28 and various standard operator inputs, such as a keyboard, trackball, mouse, or the like.
Turning now to
At step 34, using an associated input device 54 such as a mouse or the like a first portion of the image volume data set 52 is selected. A display processor 56 of the workstation 50 is used in step 36 to display the selected portion of the image volume data set 52. The first portion is displayed on a display device 58 including a first screen portion 60 for displaying a slice or other view of the patient taken from the image volume data set and also including a second screen portion 62 for displaying a completion cube image in accordance with the invention in a manner to be described below. It is to be appreciated that the display device 58 may be the monitor 28 of the workstation 12 adjacent the imaging device 20, or it may be a stand-alone apparatus remote from the imaging system 10.
A mapping processor 64 is used in step 38 to map the selected first portion of the image volume data set to a corresponding first portion of a volume completion data set 66. Preferably, the mapping is non-overlapping transform of a sub-volume on a volume representation of the image data set referred to in this application as a completion cube. Also preferably, the mapping processor 64 utilizes a shading function 66 to be described in greater detail below for purposes of shading or colorizing portions of the volume completion data set corresponding to portions of the image volume data being reviewed by the radiologist.
Lastly with regard to the preferred method 30, in step 40, the volume completion data set 66 is displayed on the second screen portion 62 of the display device 58 with the first portion of the volume completion data set according to the predetermined colorization function 58 to visually differentiate the selected first portion of the volume completion data set 52 from the remaining portion of the volume completion data set.
It is to be appreciated that the preferred method of clinical review of images of patients described above in connection with
In the case of liver scans as another example of the alternative embodiment, a set of three (3) image volume data sets are acquired at each liver phase including a hypatic enhancement, portal enhancement, and non-arterial enhancement phase. A corresponding set of three (3) volume completion data sets are also provided in a corresponding relationship with each acquired image volume data set during the three (3) liver phases. The display mapping and colorization and shading steps described above in connection with the static investigation are repeated as the investigation by the radiologist unfolds.
As a final but not exhaustive list of examples of the alternative embodiment of the use of the subject invention to perform multi-phasic studies, the volume completion cube can be used in investigations made using images with contrast and without contrast as well as images taken sometime in the past against images taken in the future such as to determine the effectiveness of chemotherapy or other treatments.
a and 4b illustrate the images 70, 72 displayed on the first and second screen portions 60, 62 of the display device 58 during a typical patient image volume review by a radiologist. More particularly, as the radiologist displays images 70 such as sections, slabs, projections, etc. of the patient's image volume data set 52 on a display port 60, a supplemental graphical representation of the image volume in the form of a completion cube 72 is updated in a separate viewport 62 of the display device 58 to indicate those aspects of the data set which have been reviewed, how much time has been spent in reviewing each portion, and a level of detail of review thereof. The preferred mode of operation of the invention is to map, using the mapping processor 64 each image in the display viewport 60 with a unique mapping to the volume completion data set 66 which is displayed in the second viewport 62 as a completion cube in accordance with a shading or colorization function 68. It is to be appreciated that the mapping/projection is the intersection of the completion cube with the sub-volume being displayed which may be an axial slice, a slab, volume projections, oblique MPR views, MPRs, or a cine display. The projections on the completion cube are automatically shaded or colorized according to the colorization function 68 to indicate the amount of time the image is displayed or, more appropriately, to indicate the level of focus or the attention paid by radiologists on selected portions of the image volume.
a-5d illustrate a sequence of completion of a shading of the completion cube 72 representing a review of axial images conducted by a radiologist. In the example illustrated in those figures, the review process of the patient case is from superior to inferior. Also, it is to be appreciated that the axial planes or sections intersect the completion cube 72 on sagittal and coronal sides since the axial planes are perpendicular with the sagittal and coronal axes. It is advantageous that all three (3) sides of the completion cube are presented to the radiologist. The views contained within the cube are projected to the faces of the cube to be readily identified.
The empty or unshaded completion cube 72 illustrated in
b shows the completion cube 72 with a first portion 76 thereof shaded representative of the review of a plurality of axial slices of the image volume data set having been reviewed by the radiologist. As further shown in that figure, the axial plane is ?framed? using darkened regions 80 to further assist the radiologist in examining the image volume.
c and 5d illustrate the completion cube 72 in various stages of shading including the first portion 78 discussed above, a second portion 82 and a third portion 84. As can be seen, the second portion of shading 82 of the completion cube 72 is lighter than the first and third portions 78, 84 indicating that a potentially under-reviewed sub-volume of the image volume data set exists. Again, preferably, the shading represents the amount of time or focus that has been spent on any sub-volume in the image volume data set.
a and 6b show the subject completion cube shaded in accordance with the present invention as a result of various selectable clinical evaluations of the patient image volume. More particularly, as illustrated in
b illustrates a completion cube 72 in accordance with the invention wherein the image volume review was conducted using an oblique MPR review process. As shown, a shaded region 100 bisects the completion cube 72 at an oblique angle and divides the cube into a large first portion 102 and a smaller second portion 104.
Turning now to
It is to be appreciated that several shading functions can be defined which represents the amount of time spent reviewing each slice. The curves shown in
With reference lastly to
The invention has been described with reference to the preferred embodiment. Obviously, modifications and alterations will occur to others upon reading and understanding this specification. It is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalence thereof.
Number | Date | Country | Kind |
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60372060 | Apr 2002 | US | national |
Filing Document | Filing Date | Country | Kind |
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PCT/US03/11083 | 4/11/2003 | WO |