The present invention pertains generally to Computer-Aided Detection (CAD) of features on medical imagery, and more particularly to systems, system components, and methods for use in CAD mammography.
CAD mammography systems have existed now for more than a decade. Such systems digitize traditional film mammograms, and then use computer algorithms to locate suspicious regions in one view, several views, or a time-series of mammograms. Additionally, some imaging systems now directly produce digital mammogram data and thus can be integrated with embedded CAD algorithms without digitization of film output.
A radiologist uses a CAD system by first viewing a set of mammogram films (or digital equivalent), and then checking the CAD results for the same set of films on a computer monitor. The computer monitor in a film-based system shows lower-resolution images of the films, with marks superimposed to show suspicious regions located by the CAD algorithms. If the radiologist has noted nothing suspicious in the films, but the CAD system identifies a suspicious region, the radiologist may re-evaluate the identified region on the films. Obviously, the more effective the CAD algorithms are at identifying real trouble regions without falsely identifying normal tissue, the more weight the radiologist will give to the CAD results. Also important, however, is the ease of use of the system, both for radiology technicians and for radiologists, so that the system provides a real benefit without unduly increasing workload.
Many radiologists view a large number of cases at a single sitting on a motorized film “multi-viewer,” which can be loaded with films for tens, or sometimes even hundreds, of cases. The radiologist manipulates controls on the multi-viewer to advance films and thus efficiently process a batch of cases.
Commercial CAD systems generally locate a computer monitor near a film viewer, where the radiologist can view both comfortably. Commercial CAD systems locate and display CAD results for a set of films in several ways.
Some CAD systems locate a keyboard on the multi-viewer to allow a radiologist to retrieve CAD results by entering a patient name or other identifier, where a technician has previously entered that information in the system.
Some CAD systems require that a unique barcode sticker be affixed to the films. Some systems simply use a barcode sticker peeled from a roll of unique stickers and affixed to the films prior to scanning, and read the barcode during film scanning. Other systems generate and print out a barcode when a case is scanned, and the technician affixes the barcode after scanning but before the films are transferred to a multi-viewer. After scanning and after the barcode is affixed, the radiologist uses a barcode wand or gun to read the sticker and cause the CAD system to display CAD results for that case.
Finally, some CAD systems are directly integrated with a multi-viewer, so that a radiologist can advance to the next film and advance to the next set of CAD results simultaneously. The latter systems require that a technician load cases to a scanner with cardboard separators interspersed between the cases. The scanner scans a set of films, and then scans the cardboard separator and reads a barcode affixed to the cardboard. When the technician subsequently hangs films on a multi-viewer, he slides the cardboard separators through a barcode-reader slot on the side of the machine, which then loads the corresponding CAD results in the same order.
Another integrated CAD system is described in U.S. Pat. No. 5,748,173. This integrated system uses a camera, bar code reader, or magnetic decoder to read identification information for a film loaded on a viewer, once that film is presented to an operator. The identification information is used to locate CAD images and results associated with the presented film. The located CAD images and results are retrieved from a database and displayed on a computer monitor.
The detailed description of the embodiments is best understood when read in view of the attached Figures, wherein:
CAD System Overview
The present disclosure describes a CAD system, system components, and methods for operation. Referring to
Film scanner 210 provides a capability for high-resolution scanning of medical imaging films. Film scanner 210 may be, for instance a CAD Pro scanner available from Vidar Systems Corporation.
Touch screen display 220 provides an interactive interface for a technician. The technician manipulates a few simple buttons displayed on display 220 to start and stop the system, but has no more-detailed access to the system. Any commercial LCD touch screen display can be used for this task, for instance an ET1247L display available from Elo Touchsystems, Inc.
Color laser printer 230 is used to create case printouts, as will be described below. Although other types of printers (inkjet, black-and-white laser, etc.) can be substituted, a color laser printer is preferred to reduce cost/sheet and increase reliability, particularly for high-volume applications. Color is preferred in order to permanently and visibly record any marks found by the CAD algorithms. Any commercial color laser printer can be selected, for instance a C720 or C510 printer available from Lexmark International, Inc.
Server1250 contains dual Central Processing Units (CPUs), CPU A 252 and CPU B 254, which are, e.g., Intel® Xeon® processors available from Intel Corporation, and a magnetic hard drive 256 to store case images and results. CPU A runs software to integrate and control overall system function, as will be described throughout this specification. Accordingly, CPU A: controls film scanner 210 through, e.g., a SCSI (Small Computer System Interface) or USB (Universal Serial Bus) port; interfaces with a technician through a touch screen display 220 connected to Server1 through a Video output and a serial or USB port; interfaces with color laser printer 230 over, e.g., an Ethernet connection; interfaces with viewing stations over an Ethernet connection; and interfaces with Server2 over an Ethernet connection. In some embodiments, each server is configured with only two Ethernet ports, and thus color laser printer 230 connects to the second Ethernet port on Server2, and CPU A spools print jobs to color laser printer 230 through its Ethernet connection to Server2. Alternately, any or all of the Ethernet devices in station 200 could connect directly to a LAN instead of to each other. Dedicated connections are preferred, however, as this allows the CAD system to function whether an external LAN is available or not. Server1 preferably has other ports, such as keyboard and mouse ports, that remain unconnected during normal system operation but are available for use during system configuration and/or maintenance. A modem port is also provided, and a modem optionally can be installed on CAD station 200, e.g., as a backup or alternative to an external LAN connection. Maintenance can also preferably be performed remotely through an Ethernet port.
CPU B is used for CAD processing, i.e., it processes cases assigned to it by CPU A and then notifies CPU A when results are available.
Server2260 is optional, but increases system performance by providing third and fourth CPUs (CPU C 262 and CPU D 264) to process cases concurrently with CPU B. Like with CPU B, CPUs C and D are assigned cases by CPU A and return results to CPU A. Server2 may contain identical hardware to Server1, which provides redundancy and simplifies maintenance. Minor variations, such as no hard disk or a different size hard disk, may be incorporated as well. When a hard disk is part of Server2, Server2 can also export the disk or a partition of the disk (using, e.g., NFS (Networked File System) or CIFS (Common Integrated File System) software) to Server1 for additional case storage. As yet another alternative or supplement, Server2 and/or Server1 can mount a remote disk available to CAD station 200 over its external Ethernet connection.
UPS 240 supplies battery power to film scanner 210, touch screen 220, Server1, and Server2 in the event of power interruption. UPS 240 notifies Server1 through a USB connection when power is interrupted, and Server1 notifies Server2. Server1 finishes scanning any case that is currently being scanned by film scanner 210, waits for CPUs B, C, and D to complete any cases currently being processed or requests that the cases be suspended, displays a message on the touch screen stating that main power has been lost, and then initiates an orderly shutdown if the power interruption has not been resolved. This allows the system to reach an orderly stopping point that will not leave a technician confused as to what has and has not been processed, and should not result in a missing case.
Viewing station 300 provides the remaining functionality for CAD system 100. A typical viewing station 300 is illustrated in
The embedded computer can be a custom standalone unit, as will be described in one embodiment. In other embodiments, the display and embedded computer can be integrated into the display case. For instance, an Apple iMac G5 can be adapted to provide the viewing station functions, as will be described in more detail below.
With the preceding general system overview as background, a more detailed description of various features and components of CAD system 100 will now be undertaken. The CAD station general design, view station general design, and the case scanning/processing function, case loading function, and case viewing function will each be described in turn.
CAD Station Hardware
Lower enclosure 202 houses UPS 240, servers 250 and 260, and in some embodiments a modem (not shown). The top of enclosure 202 forms a shelf 203, upon which color laser printer 230 rests. This design places the heavy UPS at the bottom of the cart, and places the printer low on the cart, thus lowering the center of gravity of the cart and increasing stability. Further, since radiology technicians will seldom if ever need access to the servers, UPS, and fan tray, these components are located out of the way so that easy access can be provided to the components that the technician will access.
Another benefit of this design is that the mechanical noise generated by the system cooling fans is attenuated at walking level. Air enters the lower enclosure through slots in the bottom of the enclosure along the front and one side of the enclosure floor (see
The lower enclosure also provides rack space, so that rack-mounted servers and a rack-mounted UPS can be used (see
Lower enclosure 202 also provides a secure shelf for laser printer 230. The sides of the lower enclosure extend up along the sides of the printer shelf 203 to prevent the laser printer form shifting off the sides of the cart. The front and rear of the shelf are left open to allow access to paper trays and other replenishable-printer-supply doors.
Shelf 206 provides a support for film scanner 210. The footprint of shelf 206 approximates the footprint of the film scanner, so that a technician has easy access to the film loading slot 212 and the film discharge slot 214 of scanner 210. Additionally, the close proximity of film discharge slot 214 to printout discharge slot 232 of printer 230 makes it easy for a technician to gather scanned films and CAD printouts for transfer to a viewing station.
Mounting bracket 208 attaches to shelf 206. Preferably, the film scanner discharge slot 214 slides between the two sides of mounting bracket 208, thus positioning and mechanically constraining the scanner on the cart. Touchscreen display 220 mounts to the front of bracket 208, thus placing the display in an easily viewable position.
Viewing Station Hardware
The viewing station is designed for mounting on or near an existing film viewer, although the components could be integrated into a new film viewer and provided as a package.
Referring to
Also visible on the tabletop in
Embedded computer 310 is not shown in
The embedded computer could be replaced in some embodiments with a more traditional desktop or tower unit, although this would generally increase bulk, power consumption, and noise, and would make the system more susceptible to theft and damage.
Another preferred viewing station embodiment is illustrated in
The various connections to the embedded computer are shown in a connector region 380 along one side of the back of case 325. Wires for the mouse, LAN, barcode reader, and film viewer interface are routed along a hollow enclosure 355 on the top of mounting arm 350 to corresponding connectors in connector region 380. Optionally, one or more of these connections can be replaced with a wireless interface, e.g., an IEEE 802.11g or Bluetooth interface.
Other structural features of the viewing station are also depicted in
CAD Station User Operation
CAD station 200 preferably presents a simple user interface to a technician responsible for loading cases into the CAD system.
Referring first to
The second informational display informs the technician of CAD progress on the newly-scanned cases. In the example of
Returning to
After a four-film set has been successfully scanned, if the scanner detects additional films in its loading tray, Server1 loops back to create a new case and repeat the steps to enter digitized films for that case. Meanwhile, a “New Case Ready for CAD” event causes a process to determine one of CPUs B, C, or D to receive the first set of digitized films for CAD processing. The case is transferred to the appropriate CPU, and Server1 updates the “Cases Processing” region of the touch screen display periodically to indicate the progress of the CAD processing.
When the “Stop” button is pressed by a technician, the system aborts scanning of the current case, but continues CAD processing on any cases already entered into the system.
When CAD results for a case are available, Server1 saves the results to the case database. A results page is then generated and printed on the color laser printer. The ordering of the results pages on the printer is the same order as the films sets fed into the film scanner. This allows the technician to take the two stacks (films and printouts) to a viewing station for loading, or easily distribute films and results pages to case files.
Below the barcode are left and right headers. The left header indicates whether the results page was generated with “Marks On” or “Marks Off.” For instance, in
The right header indicates the CAD software version used to process the film set, the clinic name, date and time of processing, and case number.
The printout is preferably of suitable quality that it can be placed in the file to verify that CAD was used on the film set and the results obtained. In addition to header and results, the printout shows printed versions of the four film scans, each having a corresponding label data extracted from that film placed directly below it. The label is extracted from each image during CAD processing. A technician or radiologist can verify from this data that the films were properly loaded and that each belongs to the same patient.
Returning briefly to
Some embodiments are designed such that when the case storage database reaches a certain size, new cases begin to replace the oldest cases in the database. The oldest cases could simply be deleted, or moved to an off-system archive database. Also, when two or more CAD stations operate in the same clinic, the requested case may be valid but not stored on this CAD station. In all of these cases, the CAD station would respond to the viewing station that the requested case is not in the system.
Viewing Station Load Cases Mode
The viewing station has two basic modes of user operation, a “Load Cases” mode and a “View Cases” mode. The Load Cases mode will be explained first.
A row of buttons across the bottom of the display can be selected with a mouse to cause most of the other events in
A user can step through the panels using scroll events, generate either by grabbing the slider bar with the mouse and sliding it, or by manipulating the mouse scroll wheel. As the panels are scrolled, the middle of the three visible panels becomes the active panel which is controlled using many of the buttons at the screen bottom.
In Load Cases mode, barcode scanner 330 is activated. One method of coordinating CAD results loading with loading of a film multi-viewer is to load the film set on a panel of the multi-viewer, and then run the corresponding CAD results sheet for that film set under the barcode laser scanner to cause a
When the case has been loaded, the small panel display for the current panel (with a brighter border to indicate that it is the active panel) is updated with a date and case number, a patient label from a non-blank film, and a thumbnail for each of the four films stored in the case file. Finally, the current panel is incremented and scrolled to prepare the system for a next barcode read event. In some embodiments, when the current panel is incremented a message can also be sent to the controller of a coupled film multi-viewer, allowing the film multi-viewer to advance to a next panel as well.
A technician can use the buttons at the bottom of the display to further control loading options. The “Clear All Panels” button creates an event that first queries the user for confirmation, and upon confirmation removes all currently loaded cases, restoring the system display to that shown in
The next two buttons change the film order to correspond with radiologist preferences, and affect all loaded cases. The “Swap MLO & CC” button reverses the current ordering of CC and MLO views in the panel display (and radiologist display), as shown in
The “Print Case” and “Print Report” buttons cause events that send a request to print case information to the CAD server that holds the full case data.
Finally, the “View Cases” button switches the viewing station out of Load Cases mode and into View Cases mode, with the current panel as the displayed panel in View Case mode.
Other control arrangements exist in other embodiments. For instance, instead of the swap display buttons, a single options button can activate a pop-up control panel with various display options. In one embodiment, the pop-up control panel also allows the user to set the number of panels.
Viewing Station View Mode
The radiologist can choose to show or hide the labels extracted from the four films, which identify the patient. To toggle, e.g., between the views of
The radiologist navigates through the loaded panels using mouse click and/or mouse wheel events. A mouse click event that is not on one of the clickable buttons or a mouse wheel rotate down event cause the same response. If marks are hidden, like in
If marks are already displayed on the current panel, a mouse click or mouse wheel rotate down event advances the display to the next occupied panel and displays the images without marks. A mouse wheel rotate up event advances the display backwards to the previous occupied panel. This ability allows the radiologist to easily navigate through the loaded panels using single clicks without having to aim and click the mouse on a button each time.
Mouse manipulation can also be defined to cause other display behavior. For instance, the viewing station can be set to a mode (not shown) that zooms in on an area of a digitized film image when that area is pointed to and clicked or “boxed” by a radiologist.
The radiologist can also toggle between showing and hiding marks using the “Show Marks” button (
The Quick View button allows a radiologist to quickly navigate to a particular loaded case, or load an unloaded case, using a CAD results printout with a barcode. When the “Quick View” button is selected, the barcode scanner is activated (it is normally deactivated in View Mode to reduce stray light) until a single barcode is passed under the barcode scanner. The viewing station then locates the corresponding panel, or requests the case from the CAD station if it is not loaded, and then places that case on the display.
The radiologist can also access the Load Panels functionality using the Load Panels button. Finally,
Other modes of panel navigation are possible. For instance, if the film multi-viewer has a serial or other electronic output indicating when panels are advanced, that output can be connected to the viewing station to step the CAD view at the same time. Another possibility would be to have the CAD viewing station instruct the film multi-viewer to step when the viewing station steps. A separate button (not shown) will appear on the display when the CAD viewing station has an established communication link with a film multi-viewer. When the film multi-viewer and CAD viewing station are not slaved to each other, the button text reads “Attach Viewer.” When the film multi-viewer and CAD viewing station are synchronized, the button text reads “Detach Viewer.”
As shown in
When the film multi-viewer and CAD viewing station are synchronized, panel navigation messages are communicated between the CAD viewing station embedded computer and a controller in the film multi-viewer. When an operator selects a new panel on the film multi-viewer, the multi-viewer controller sends a notification message to the embedded computer, creating a viewer message received event as shown in
Although described and shown for the viewing station view mode, synchronization between the CAD viewing station and film multi-viewer can be activated in similar fashion in the load cases mode.
Although some embodiments of representative CAD systems, components, and methods have been described, many other additional or alternative features are possible. For instance, although the CAD station described requires four properly ordered films for each case, alternative embodiments can detect and correct film order/orientation. When labels are extracted by the CAD algorithms, the labels can be cross-checked to automatically verify that they belong to the same patient. Optical character recognition can also be used to retrieve identifying information directly from the film labels. Although the described process is “stickerless,” an alternate embodiment could generate one or more stickers to be applied directly to a film. Preferred embodiments use a laser barcode scanner mounted to the back of a CAD display, but other possibilities exist. Other types of barcode scanners, such as charge-coupled-device scanners, can be used. The scanner itself can be mounted in other embodiments within the display case, mounted to the bottom, front, or side of the display case, or possibly even on some part of the display arm.
The preceding embodiments are exemplary. Although the specification may refer to “an,” “one,” “another,” or “some” embodiment(s) in several locations this does not necessarily mean that each such reference is to the same embodiment(s), or that the feature only applies to a single embodiment.
This case claims priority to and incorporates by reference copending U.S. Provisional Patent Application 60/525,228, filed Nov. 24, 2003.
Number | Date | Country | |
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60525228 | Nov 2003 | US |