Interfacing Fuji CR in a DICOM Network Environment

Transcription

1 Interfacing Fuji CR in a DICOM Network Environment Wayne T. DeJarnette, Ph.D., Valmore Albrecht, RT, Alan Orth, RT, Jon Sayer, M.S. DeJarnette Research Systems, Inc. 401 Washington Avenue Towson, MD Abstract CR technology, especially that manufactured by Fuji Medical Systems, Inc., is now well established and accepted in clinical environments. It has become clinically desirable to use CR digital image acquisition as a primary image input into PACS and teleradiology systems. The techniques and technology useful in interfacing Fuji CR to PACS and teleradiology systems will be discussed. Interfacing of Fuji laser imagers to PACS will also be discussed. Introduction Figure 1 shows a typical CR configuration as delivered by Fuji Medical Systems, Inc. Many such systems have been installed worldwide. The configuration consists of a Fuji CR, a Fuji Workstation (HI-C654) and a Fuji Laser Imager. The CR is used to digitize the CR phosphor plate. The raw image data is then processed for printing and sent to the Fuji Laser Imager. The raw image data is also transmitted to the Fuji Workstation for viewing, reprocessing and potentially reprinting. Most installed Fuji CRs are in non-pacs environments and as a consequence, the acquired images are distributed by means of film only. Interfacing of the Fuji CR systems to non-proprietary PACS was not a design requirement for these early systems. The only provision made for interfacing beyond this local system is of a proprietary nature. The question then arises as to how does one interface a Fuji CR system to a non-proprietary DICOM based PACS or teleradiology system, in a clinically useful fashion. Fuji LP Proprietary Fuji DMS Proprietary Fuji Proprietary Protocol Fuji Printer Fuji HIC-654 Figure 1 In order to answer this question, one must consider the workflow model which is used in acquiring CR images. A technologist will take one or more x-ray plates for a given patient. The plates must then be identified, by some means, of belonging to that patient, and then digitized by the CR plate reader. The digitized x-ray image can then have QC (quality control) performed on it or not, depending on radiology departmental policies and preferences. In a PACS or teleradiology environment, one would then like to distribute the acquired images for softcopy review and in some instances printing. The standard Fuji CR configuration as represented in figure 1, only addresses some of this workflow model. The standard configuration with HI-C654 Workstation does an excellent job of providing QC capability for the system. Unfortunately, the proprietary nature of its external digital interfaces makes the device less useful in a DICOM network environment, for distributing those images. The standard configuration also is sub-optimal in terms of associating patients with images. Until recently, the only process was a totally manual process. To make best use of a Fuji CR in a DICOM network environment, one must address these two issues. The Fuji Laser Imager in the configuration can only print images from the CR and not other modalities. When viewed in

2 the light of a DICOM network environment, this is an obvious waste of resource. It is not a requirement that this issue be addressed in making use of a Fuji CR in a DICOM PACS, however, there are improvements which can be made in such an environment. In the remainder of this paper, I will address each of these issues: - getting Fuji CR images into a DICOM network (Image Interface) - correlation of Fuji CR produced images with patient information (Demographic Interface) - making use of an existing Fuji Laser Imager in a DICOM network environment. (Network Printing) I will also provide a set of guidelines and a decision matrix which will help purchasers of CR interfacing technology assess their needs. Image Interface There are two types of digital image interfaces available in the standard Fuji CR configuration. One is a proprietary parallel interface, known as DMS, and the other is a proprietary ethernet interface available on the HI-C654. The DMS interface hardware is capable of supporting a number of application specific proprietary protocols, such as printing and the delivery of raw data images to an external device. Fuji has licensed this technology, in the past few years, to a small number of companies. Until recently, the only product which could be used, by someone other than Fuji, to interface to the Fuji CR system DMS port, was a Fuji DASM. Fuji would provide these DASM units to end users and other manufacturers in order to accomplish image interfaces. The author knows of no instance of Fuji making available it s proprietary ethernet interface to any other party. The Fuji DASM is not a high value added product. The DASM allows one to acquire raw image data from either the CR itself or the HI-C654. It is not possible to acquire Fuji processed images, suitable for printing, via this interface. The DASM simply converts from Fuji s proprietary DMS and associated protocols to a SCSI interface, which can be treated like a disk drive. The DASM is currently used by all vendors, other than Fuji and DeJarnette, to interface to the DMS port. Fuji products make use of Fuji proprietary interface boards in their products like the HIC. DeJarnette showed it s DIB (DeJarnette Interface Board) at RSNA 1997 and will release this board as a component of the company s new line of Fuji CR QC Workstations in early Any system level product, which is meant to provide DICOM image network connectivity, must also address the issue of whether and how to provide image processing of the raw image data. Again, Fuji has licensed a small number of companies to make use of Fuji s image processing algorithms. These algorithms and the generally used (Fuji recommended) processing parameters have been optimized for printing on Fuji film. They are not necessarily optimal for other manufacturer s film or softcopy display stations of any manufacturer (including Fuji). It is the authors experience however, that this processing and the recommended processing parameters give very good results on other manufacturer s film and on most softcopy display stations. Future clinical experience will most probably result in more optimal processing parameters being found for use on softcopy display stations. Early PACS implementors, like Dr. Eliot Siegel at the Baltimore VA, have discovered that it is possible to read raw data (unprocessed) images produced by the Fuji CR. This is accomplished by window and level adjustments on a softcopy display station. Such reading is however thought to be more time consuming and less desirable than reading an image, which has been processed using the Fuji algorithms. Reading of raw data images also requires some adjustment and training on the part of the radiologist. Today there are a number of DICOM image network interfaces available on the market. Asking the following questions can differentiate these products: - Is QC display capability provided? - If QC capability is available, is a high brightness monitor available? - If QC capability is available, what is the monitor size and resolution? - If QC capability is available, what image manipulation and processing controls are available? - Is a Fuji DASM required? (note some manufacturers place the DASM inside their product) - Are DICOM Print and DICOM Query/Retrieve supported as well as DICOM Storage? - Does the product produce processed images? 2

3 - Does the product support Fuji s HQ? - Is advanced processing available? (DRC, TAS) - Are both processed and raw data images available from the product? - Is it possible to simultaneously acquire, process and transmit images? - Does the interface device support transmission to multiple network destinations? How many? - Are other common PACS network protocols supported? (such as PACSnet which is used preferentially by both the Siemens and the GE PACS product offerings) - How many Fuji CR readers can be interfaced to the network by a single interface device? - What is the interface device throughput? (How many images an hour can be acquired, processed and transmitted over the network?) - What does it cost? By asking these questions one can determine whether the image interface device is suitable for your application. It should be noted that these interface devices are divided into two major classes, those, which provide QC capability, and those, which function as black boxes. Generally the black box or pass box interfaces are less costly than the QC Workstation variety. The black box interface is only suitable if you have no requirement for technologist QC or if you have suitable QC capability on a network display station. It is the author s experience that doing QC on a general purpose network display station is sub-optimal and that the dedicated QC Workstation is better suited to the QC task and more cost effective in the end. A second consideration will further delineate product offerings: are processed images available for network transmission from the device. If an interface product does not supply Fuji processed images, you will have to process these images somewhere else in your PACS or teleradiology system before reading them or printing them. Generally this would be done on another workstation. Demographic Interface The Fuji CR requires that it be supplied with certain demographic information. This information is used to associate the patient with the exposed phosphor plate. In the standard Fuji CR configuration, it is required that this information be entered either by means of manual entry, barcode scanning or magnetic card scanning. Only limited demographic data is available for use in this standard configuration. Patient name, patient sex, patient birthdate, patient number and acquisition date are the only data of interest to the CR reader. This is sufficient information if you are only printing the image. This is far from sufficient if one is making use of the produced image in a PACS environment. Early PACS implementors who have used Fuji CR devices in their systems have found that workflow is greatly improved if a HIS or RIS is available and interfaced to the CR reader. Through the use of such an interface it is possible to have the patient information which is input to the HIS or RIS made available to the CR reader. This eliminates the step of having the radiology technologist generate a barcode or magnetic card. Apart from the time saved in not performing this function, the incidence of inconsistent patient information between the HIS/RIS and the PACS is greatly reduced. Such inconsistency was found to be a significant problem in early PACS implementations. Today Fuji supplies the FCR Information Manager to interface its readers to HIS and RIS systems. It should be noted that the FCR Information Manager requires the existence of a DICOM Worklist Management Gateway to the HIS or RIS in order to provide this functionality. One such gateway will support many Fuji CRs as well as other modalities in the radiology department. DICOM Worklist Management Gateways are available today from two sources, DeJarnette and Mitra. State of the Art Interfacing Figures 2 and 3 illustrate the state of the art configurations, at the end of 1997, for interfacing Fuji CR to DICOM PACS and teleradiology systems. Figure 2 illustrates a Fuji CR with IDT (AC3 like) interfaced to a HIS/RIS system and a PACS. This figure illustrates the use of a black box interface with no QC capability. The HIS/RIS makes available a worklist to the FCR Information Manager, by means of a DICOM Worklist Management Gateway (not shown embedded in HIS/RIS). The technologist, after exposing the CR plate, places the plate in the reader and selects the appropriate patient registration from the worklist displayed by the FCR Information Manager. The patient demographic information is downloaded to the CR automatically and the plate is then read. 3

4 Demographic Data HIS/RIS Optional Fuji Printer Fuji LP Proprietary FCR Information Manager DICOM DICOM Imaging Gateway PACS Figure 2 Upon completion of the digitization, the DICOM Imaging Gateway receives the image and limited demographics from the CR reader. The DICOM Imaging Gateway then queries either the FCR Information Manager or the Worklist Management Gateway to obtain all of the demographic information available for the selected patient registration. This last step is required because only five demographic fields can be passed through the CR reader. The DICOM Imaging Gateway must perform this step (demographic re-population) if a conformant DICOM CR object is to be constructed for network transmission. Only a few of the DICOM Imaging Gateways on the market perform this demographic re-population. The DICOM Imaging Gateway is also responsible for performing all Fuji image processing. Again it should be noted that not all gateways make available the processed image. Finally, the image and demographics are automatically transmitted across the DICOM network for storage, display and/or printing. Figure 3 illustrates a Fuji CR with IDT (AC3 like) interfaced to a HIS/RIS system and a PACS. This figure illustrates the use of a QC Workstation type of interface. The operation of this system is very similar to that of the pass box configuration in figure 2. The HIS/RIS makes available a worklist to the FCR Information Manager, by means of a DICOM Worklist Management Gateway (not shown embedded in HIS/RIS). The technologist, after exposing the CR plate, places the plate in the reader and selects the appropriate patient registration from the worklist displayed by the FCR Information Manager. The patient demographic information is downloaded to the CR automatically and the plate is then read. Demographic Data HIS/RIS Optional Fuji Printer Fuji LP Proprietary FCR Information Manager QC Workstation DICOM PACS Figure 3 Upon completion of the digitization, the DICOM QC Workstation receives the image and limited demographics from the CR reader. The DICOM QC Workstation then queries either the FCR Information Manager or the Worklist Management Gateway to obtain all of the demographic information available for the selected patient registration. Like the pass box this step is required to produce a conformant DICOM CR for network transmission. This last step is also only performed 4

5 by some of the DICOM QC Workstations on the market. The DICOM QC Workstation is then used to display the acquired image and examine it for proper orientation, exposure and proper patient registration. A technologist can make a decision at this point if a retake is required or if the existing raw data image needs to be reprocessed. Once an acceptable image is produced, the image is transmitted on the DICOM network for storage, display and/or printing. Again it should be noted that not all manufacturers support DICOM printing. Although it is possible to mix and match FCR Information Managers from Fuji with DICOM Imaging Gateways or DICOM QC Workstations from other manufacturers, some care must be exercised. Not all combinations will provide equal performance or functionality. Advanced Interfacing An obvious problem with the current state of the art is the number of boxes required for the interfacing task. In order to interface a Fuji CR to a DICOM network in an optimal fashion, the 1997 state of the art typically requires 4 boxes (DASM not shown in figures, FCR Information Manager, DICOM Worklist Management Gateway and either a DICOM Imaging Gateway or a DICOM QC Workstation). It is sometimes possible to make the FCR Information Manager and the DICOM Worklist Management Gateway co-resident. It is also generally possible to share the DICOM Worklist Management Gateway among multiple CRs and/or other modalities. Nonetheless, it would be desirable to consolidate some of these boxes. HIS/RIS Demographic Data Optional Fuji Printer Fuji LP Proprietary Advanced DICOM Imaging Gateway DICOM PACS Figure 4 Demographic Data HIS/RIS Optional Fuji Printer Fuji LP Advanced QC Workstation DICOM Figure 5 PACS Figures 4 and 5 illustrate an advanced technology for interfacing Fuji CR to DICOM networked PACS and teleradiology systems. These figures illustrate pass box and QC Workstation configurations in which three boxes have been consolidated into one. These products, from DeJarnette Research Systems, are currently undergoing beta installation. 5

6 The pass box configuration illustrated in figure 4 accomplishes the same functions as the multi-box solution illustrated in figure 2. Apart from a reduction in number of boxes and the concomitant clinical space savings, a better-integrated solution results because one manufacturer is responsible for both the demographic interface and the imaging interface. Similarly the QC Workstation configuration illustrated in figure 5 produces the same benefits in the QC application. The development of these advanced Fuji CR interfacing products relied heavily on the company s experience gained in it s earlier QC Workstation product (Imageshare 2000/CR) and the company s development and manufacture of FCR Information Managers for Fuji. These advanced interfacing products have greatly improved performance (4 to 5 times faster, ~800 images per hour throughput), increased functionality and a higher level of integration. The use of direct DMS connection (no DASM) in these products results in a system with greater capability and performance. Network Printing Upon installing a DICOM network in an environment with a Fuji CR, it is frequently desired to move the Fuji Laser Imager to a point where it can be shared across the network. Today this is a costly reconfiguration. A DICOM Print Spooler or DICOM Print Workstation is required in combination with a Fuji Multi-formatter. Figure 6 illustrates such a configuration with a DICOM Print Spooler (black box). Figure 7 illustrates such a configuration with a DICOM Print Workstation. The difference between these configurations is the functionality supplied. The Print Workstation, in addition to its ability to spool print jobs, can also be used to format or reformat print jobs by means of a graphical user interface. The Print Workstation configuration allows for an operational paradigm in which a technologist is responsible for formatting and printing all films in a department. A small number of manufacturers (including DeJarnette) today supply DICOM Print Spoolers and/or DICOM Print Workstations that will function in such a configuration. DICOM NETWORK DICOM Print Non-Fuji Printers Proprietary DICOM Print Spooler Fuji Printer Fuji Multi-Formatter DICOM NETWORK Figure 6 DICOM Print Non-Fuji Printers Proprietary Fuji Printer DICOM Print Workstation Fuji Multi-Formatter Figure 7 It should be noted in both figures 6 and 7 that it is possible to interface either the Print Spooler or the Print Workstation to an imager of non-fuji manufacture without a multi-formatter. This is a result of Fuji s use of a DMS port with proprietary printing protocol for their imagers. Other manufacturers have standardized on a 3M 831/952 style interface for imagers. The Fuji Multi-formatter supplies a standard 3M 831/952 interface, which converts to the Fuji proprietary interface for the imager. It should also be noted that Fuji has a different paradigm for the operation of their imagers. Most imager 6

7 manufacturers provide no processing besides scaling and transfer function modification via LUTs in their imagers. Fuji s imagers, because they were developed for CR applications, provide some image processing suitable for printing of CR images. Not all required processing is done in the imager, the CR does some of this processing. As a result, if one is to print CR images to a Fuji imager, one must provide for the processing done by the CR reader. Ideally one would like to do away with the multi-formatter in these configurations. Figures 8 and 9 illustrate such configurations for a Print Spooler and a Print Workstation respectively. The author is not aware of such products being in clinical use today. However, a small number of companies have the technology and could bring to market such devices. DICOM NETWORK DICOM Print Non-Fuji Printers DICOM Print Spooler Figure 8 Fuji Printer DICOM NETWORK DICOM Print Non-Fuji Printers DICOM Print Workstation Fuji Printer Figure 9 Summary I have illustrated a number of ways one can make use of a standard CR configuration from Fuji, in a DICOM network environment. These techniques will work for all Fuji CRs other than the original AC1. An AC1 must be upgraded to an AC1+ to employ the techniques describe. All that is required of the institution wishing to make use of a Fuji CR in a DICOM network environment, is to decide upon a workflow model. Once this choice is made, it will become clear what functional specifications must be met by the equipment to be purchased. The answers to three questions will allow one to quickly thin the field of interfacing products which you might consider. Does a HIS or RIS exist in your institution and will you make use of it? If so, demographic interfacing to the Fuji CR is required. Do you wish to have image QC performed at the reader, or will this be done at a general-purpose workstation? If this is to be done at a general-purpose workstation (PACS Display Station), such a workstation must have sufficient functionality to perform CR QC. This will limit one in the choice of general-purpose PACS Display Stations. Finally, do you require Fuji processed images on your network? If processed images are not available from the CR interface, either pass box or QC Workstation, then you will have to make sure other components in your system can perform this processing. Generally, one would expect that this function could be performed on a DICOM PACS Display Station. Such functionality is not generally available in a PACS Display Station. Your choice of PACS Display Station 7

8 will be severely restricted if the CR interface does not supply processed images. The answers to these questions will thin the field of products for your consideration. Among the remaining products, you should then consider performance, cost and other factors. 8