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Implementation of multi-vendor DICOM standard image transfer in hospital wide ATM network
Computer Methods and Programs in Biomedicine 57 (1998) 85 – 89
Implementation of multi-vendor DICOM standard image transfer in hospital wide ATM network Michio Kimura a,*, Shigeki Tani a, Shirchin Baatar a, Yasutsugu Naito a, Takashi Kanno a, Takaya Sakusabe b, Mitsuhiro Aizawa c a
Hamamatsu Uni6ersity Hospital, Department of Medical Informatics, 3600 Handa, Hamamatsu 43131, Japan Image and Measurement, Hamamatsu Uni6ersity Hospital, Department of Medical Informatics, 3600 Handa, Hamamatsu 43131, Japan c Toshiba Medical Engineering Corporation, Hamamatsu Uni6ersity Hospital, Department of Medical Informatics, 3600 Handa, Hamamatsu 43131, Japan b
Accepted 3 February 1998
Abstract At Hamamatsu University Hospital, an ATM +FDDI network was installed in January 1995, when the hospital information system was upgraded. With its unique ‘wheel’ shape configuration, FDDI automatically backs up in case of an ATM switch failure. The authors implemented a DICOM image database server and DICOM viewer in the Hamamatsu University Hospital ATM +FDDI network. The DICOM standard worked well between different vendor products. In sending 512 ×512, 2 byte CT images, 40% of the transfer time was spent for the network data transfer, which is 70% of the theoretical value of 10 Mb peripheral transfer rate. Meanwhile, ATM load factor increased less than 0.5%. As we have a very fast data transfer network, we must check display speed, hard disc access time, PC bus speed, and display software, in order to enjoy the high speed network transfer fully. The sequence of image transmission within a study is not stated in the DICOM document and is depending on the server. Therefore, there should be an agreement between server and clients, still more than DICOM, in order to make better PACS. © 1998 Elsevier Science Ireland Ltd. All rights reserved. Keywords: DICOM; MIPS; PACS; ATM; Hospital information system
1. Introduction
* Corresponding author. Tel.: + 81 53 4352770; fax: + 81 53 4352769; e-mail. [email protected]
No doubt DICOM image transfer standard has accelerated implementation of picture archive and communication systems (PACS) [1]. In Japan, the
0169-2607/98/$19.00 © 1998 Elsevier Science Ireland Ltd. All rights reserved. PII S0169-2607(98)00057-1
86
M. Kimura et al. / Computer Methods and Programs in Biomedicine 57 (1998) 85–89
Fig. 1. Hamamatsu university hospital network.
Japan industries association for radiation apparatus (JIRA) is a counterpart of the ACR-NEMA committee. They have published MIPS standard, as a Japanese version of DICOM [2]. The new network technology, which gives us data transfer fast enough for large image data, is the asynchronous transfer mode (ATM) network. There are already some reports of implementation in hospital PACS [3], and regional healthcare network [4]. It was important to clarify how the ATM network could be used for large image data transfer with millions of small textual hospital information system messages. It was also important to prove that DICOM standard could be used even between different vendor products, and to illustrate what is still needed to make a PACS friendly for users.
2. Description of system installation
2.1. Hamamatsu Uni6ersity Hospital ATM + FDDI network In January 1995, Hamamatsu University Hospital installed a new hospital-wide data network, in connection with a total grade-up of the hospital information system (Fig. 1) [5]. As shown in the figure, it is basically a star-type ATM network with ATM switch at the center. This ATM switching mode is the usual data transfer method used in this network. At the same time, however, 13 routers connected to the ATM star LAN also have FDDI interface. These routers are also connected to the FDDI loop LAN. By this ‘Wheel’ shaped network configuration, the router can detect a failure of the ATM switch or star LAN and detour the data flow to the FDDI loop.
M. Kimura et al. / Computer Methods and Programs in Biomedicine 57 (1998) 85–89
87
Fig. 2. DICOM image viewer.
Some ATM star links are connected to the main frame computer, which contains the large data base of HIS and the hospital billing system. Others are connected to each HIS client, more than 400 in the hospital. At the time of installation this was the first case of a daily used information system by an ATM star network. It showed that these technologies had matured enough to be used for a real world information system. However, the current data transfer speed to/ from the terminals is limited to 10 Mb, and a future face lift is within the consideration of this network design. Peripheral connection cables used are category five non-shield twisted pairs (100 Base-TX). Thus, simply by upgrading the hubs and routers to 100 Mb transfer speed conformant, which are now still expensive but soon to become inexpensive, data transfer rate will be up to 100 Mb, terminal to terminal, without paying the
then-still high cost of cable installation within the hospital building.
2.2. DICOM image data base ser6er and client The DICOM standard [1] conformant image data base, which acts as a query/retrieve service class provider, is made by Image and Measurement, based on CTN software provided for RSNA 95 demonstration [6]. Hardware used is SPACStation 20/50, connected to a 10 Mb hub at ‘4F: Computer room’ as shown in Fig. 1. The DICOM standard conformant image viewer shown in Fig. 2 is a query/retrieve service class user. The software is made by Toshiba Medical Engineering, and the hardware, an FMV560, is a PC made by Fujitsu with Pentium 60MH, PCI bus. These viewers are located one for each ward, one for each department like radiology, pharmacy, HIS management, etc. The total num-
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M. Kimura et al. / Computer Methods and Programs in Biomedicine 57 (1998) 85–89
Fig. 3. CT images sent according to image UID.
ber is 18. The transmission measurement is taken with a client PC located by and connected to a 3F router.
3. Measurement A CT image of 512× 512, 2 bytes (0.5 MB), without compression, was used for this measurement. Total time from request by PC to display finish was 3.6 s, of which 1.5 s for display start – finish and 0.7 s for hard disc writing at PC. Thus, transmission by this network took 1.4 s which is 70% of the theoretical value of the branch LAN speed of 10 Mb. All through this measurement, the load factor of the ATM switch increased less than 0.5%.
4. Discussion This experiment has shown two aspects. First of all, by DICOM data format and protocol different
vendor products could be connected and work in harmony. In Japan, up to now, DICOM standard is mainly used between image modalities and PACS image archives, which are usually made by different vendors. PACS image archive and viewer clients, however, are mostly made by the same vendor. Secondly, regarding high speed network data transfer, 39% of the time has been spent on the network. This shows that even if the network were upgraded to 100 Mb terminal to terminal, we will have 2.4 s for the same transfer (1.5+ 0.7+ 1.4/10). We have to upgrade the display speed, hard disc access time, PC bus speed, and display software, in order to enjoy the high speed network transfer fully. Ever since the PACS was born in the 1980’s, we have been asking for better data transfer. Now it is almost in our hands, and it is time for us to check every elapsed time other than the network data transfer. To display requested images in a timely fashion, hardware upgrades are not enough. In Fig. 3, CT images are displayed seemingly not in order, but are displayed in order of image unique identifier (UID).
M. Kimura et al. / Computer Methods and Programs in Biomedicine 57 (1998) 85–89
In this study, three series of scans were performed: (1) Plain scan; (2) soon after contrast enhancement; and (3) enough after contrast. According to DICOM standard document, it is up to image modality to what sequence image UID’s were issued. It could be according to slice position, or scan time, or whatever, provided that they are unique. Image viewer software has to prepare for any kinds of image display requests, such as viewing all from the beginning, viewing only post contrast images, etc. Some image viewers may want to receive all images and make an inventory for them, then they start displaying the requested images, to serve the viewer user. This method, however, takes too much time for the users to be allowed to see a certain slice, especially in case of recently introduced high-speed CT’s and MRI’s, which may produce hundreds of images for a study. Some agreement about the sequence of image transmission between archive and client is needed to avoid the delay. However, this information is not in conformance with the statement required for DICOM implementation. Usually, between the same vendor archive and viewer, this
.
89
agreement is implicit within the vendor. Our multi-vendor implementation clarified this problem. We are not saying that DICOM conformance check is not enough, but something more than DICOM is needed to make a better PACS.
References [1] NEMA standard publication, Digital imaging and communication in medicine (DICOM), National electrical manufacturers association, 2101 L St., N.W., Washington D.C., 20037, 1993. [2] JIRA publication, MIPS-94 standard, Japan industries association for radiation apparatus, 2-18-12 Yushima, Bunkyo, Tokyo, 113, Japan, 1995. (in Japanese) [3] H.K. Huang, et al., Asynchronous transfer mode technology for radiologic image communication, Am. J. Roentogenol. 64 (1995) 1533 – 1536. [4] A.J. Duerinckx, et al., Assessment of asynchronous transfer mode (ATM) networks for regional teleradiology, PACS design and evaluation, SPIE 2711 (1996) 61 – 70. [5] M. Kimura, S. Tani, New hospital information system at Hamamatsu university hospital, Innervision (in Japanese) 10 (7) (1995) 120 – 125. [6] S.M. Moore, Observations on DICOM demonstration at the RSNA annual meeting, PACS design and evaluation, SPIE 2711 (1996) 89 – 97.
Implementation of multi-vendor DICOM standard image transfer in hospital wide ATM network Michio Kimura a,*, Shigeki Tani a, Shirchin Baatar a, Yasutsugu Naito a, Takashi Kanno a, Takaya Sakusabe b, Mitsuhiro Aizawa c a
Hamamatsu Uni6ersity Hospital, Department of Medical Informatics, 3600 Handa, Hamamatsu 43131, Japan Image and Measurement, Hamamatsu Uni6ersity Hospital, Department of Medical Informatics, 3600 Handa, Hamamatsu 43131, Japan c Toshiba Medical Engineering Corporation, Hamamatsu Uni6ersity Hospital, Department of Medical Informatics, 3600 Handa, Hamamatsu 43131, Japan b
Accepted 3 February 1998
Abstract At Hamamatsu University Hospital, an ATM +FDDI network was installed in January 1995, when the hospital information system was upgraded. With its unique ‘wheel’ shape configuration, FDDI automatically backs up in case of an ATM switch failure. The authors implemented a DICOM image database server and DICOM viewer in the Hamamatsu University Hospital ATM +FDDI network. The DICOM standard worked well between different vendor products. In sending 512 ×512, 2 byte CT images, 40% of the transfer time was spent for the network data transfer, which is 70% of the theoretical value of 10 Mb peripheral transfer rate. Meanwhile, ATM load factor increased less than 0.5%. As we have a very fast data transfer network, we must check display speed, hard disc access time, PC bus speed, and display software, in order to enjoy the high speed network transfer fully. The sequence of image transmission within a study is not stated in the DICOM document and is depending on the server. Therefore, there should be an agreement between server and clients, still more than DICOM, in order to make better PACS. © 1998 Elsevier Science Ireland Ltd. All rights reserved. Keywords: DICOM; MIPS; PACS; ATM; Hospital information system
1. Introduction
* Corresponding author. Tel.: + 81 53 4352770; fax: + 81 53 4352769; e-mail. [email protected]
No doubt DICOM image transfer standard has accelerated implementation of picture archive and communication systems (PACS) [1]. In Japan, the
0169-2607/98/$19.00 © 1998 Elsevier Science Ireland Ltd. All rights reserved. PII S0169-2607(98)00057-1
86
M. Kimura et al. / Computer Methods and Programs in Biomedicine 57 (1998) 85–89
Fig. 1. Hamamatsu university hospital network.
Japan industries association for radiation apparatus (JIRA) is a counterpart of the ACR-NEMA committee. They have published MIPS standard, as a Japanese version of DICOM [2]. The new network technology, which gives us data transfer fast enough for large image data, is the asynchronous transfer mode (ATM) network. There are already some reports of implementation in hospital PACS [3], and regional healthcare network [4]. It was important to clarify how the ATM network could be used for large image data transfer with millions of small textual hospital information system messages. It was also important to prove that DICOM standard could be used even between different vendor products, and to illustrate what is still needed to make a PACS friendly for users.
2. Description of system installation
2.1. Hamamatsu Uni6ersity Hospital ATM + FDDI network In January 1995, Hamamatsu University Hospital installed a new hospital-wide data network, in connection with a total grade-up of the hospital information system (Fig. 1) [5]. As shown in the figure, it is basically a star-type ATM network with ATM switch at the center. This ATM switching mode is the usual data transfer method used in this network. At the same time, however, 13 routers connected to the ATM star LAN also have FDDI interface. These routers are also connected to the FDDI loop LAN. By this ‘Wheel’ shaped network configuration, the router can detect a failure of the ATM switch or star LAN and detour the data flow to the FDDI loop.
M. Kimura et al. / Computer Methods and Programs in Biomedicine 57 (1998) 85–89
87
Fig. 2. DICOM image viewer.
Some ATM star links are connected to the main frame computer, which contains the large data base of HIS and the hospital billing system. Others are connected to each HIS client, more than 400 in the hospital. At the time of installation this was the first case of a daily used information system by an ATM star network. It showed that these technologies had matured enough to be used for a real world information system. However, the current data transfer speed to/ from the terminals is limited to 10 Mb, and a future face lift is within the consideration of this network design. Peripheral connection cables used are category five non-shield twisted pairs (100 Base-TX). Thus, simply by upgrading the hubs and routers to 100 Mb transfer speed conformant, which are now still expensive but soon to become inexpensive, data transfer rate will be up to 100 Mb, terminal to terminal, without paying the
then-still high cost of cable installation within the hospital building.
2.2. DICOM image data base ser6er and client The DICOM standard [1] conformant image data base, which acts as a query/retrieve service class provider, is made by Image and Measurement, based on CTN software provided for RSNA 95 demonstration [6]. Hardware used is SPACStation 20/50, connected to a 10 Mb hub at ‘4F: Computer room’ as shown in Fig. 1. The DICOM standard conformant image viewer shown in Fig. 2 is a query/retrieve service class user. The software is made by Toshiba Medical Engineering, and the hardware, an FMV560, is a PC made by Fujitsu with Pentium 60MH, PCI bus. These viewers are located one for each ward, one for each department like radiology, pharmacy, HIS management, etc. The total num-
88
M. Kimura et al. / Computer Methods and Programs in Biomedicine 57 (1998) 85–89
Fig. 3. CT images sent according to image UID.
ber is 18. The transmission measurement is taken with a client PC located by and connected to a 3F router.
3. Measurement A CT image of 512× 512, 2 bytes (0.5 MB), without compression, was used for this measurement. Total time from request by PC to display finish was 3.6 s, of which 1.5 s for display start – finish and 0.7 s for hard disc writing at PC. Thus, transmission by this network took 1.4 s which is 70% of the theoretical value of the branch LAN speed of 10 Mb. All through this measurement, the load factor of the ATM switch increased less than 0.5%.
4. Discussion This experiment has shown two aspects. First of all, by DICOM data format and protocol different
vendor products could be connected and work in harmony. In Japan, up to now, DICOM standard is mainly used between image modalities and PACS image archives, which are usually made by different vendors. PACS image archive and viewer clients, however, are mostly made by the same vendor. Secondly, regarding high speed network data transfer, 39% of the time has been spent on the network. This shows that even if the network were upgraded to 100 Mb terminal to terminal, we will have 2.4 s for the same transfer (1.5+ 0.7+ 1.4/10). We have to upgrade the display speed, hard disc access time, PC bus speed, and display software, in order to enjoy the high speed network transfer fully. Ever since the PACS was born in the 1980’s, we have been asking for better data transfer. Now it is almost in our hands, and it is time for us to check every elapsed time other than the network data transfer. To display requested images in a timely fashion, hardware upgrades are not enough. In Fig. 3, CT images are displayed seemingly not in order, but are displayed in order of image unique identifier (UID).
M. Kimura et al. / Computer Methods and Programs in Biomedicine 57 (1998) 85–89
In this study, three series of scans were performed: (1) Plain scan; (2) soon after contrast enhancement; and (3) enough after contrast. According to DICOM standard document, it is up to image modality to what sequence image UID’s were issued. It could be according to slice position, or scan time, or whatever, provided that they are unique. Image viewer software has to prepare for any kinds of image display requests, such as viewing all from the beginning, viewing only post contrast images, etc. Some image viewers may want to receive all images and make an inventory for them, then they start displaying the requested images, to serve the viewer user. This method, however, takes too much time for the users to be allowed to see a certain slice, especially in case of recently introduced high-speed CT’s and MRI’s, which may produce hundreds of images for a study. Some agreement about the sequence of image transmission between archive and client is needed to avoid the delay. However, this information is not in conformance with the statement required for DICOM implementation. Usually, between the same vendor archive and viewer, this
.
89
agreement is implicit within the vendor. Our multi-vendor implementation clarified this problem. We are not saying that DICOM conformance check is not enough, but something more than DICOM is needed to make a better PACS.
References [1] NEMA standard publication, Digital imaging and communication in medicine (DICOM), National electrical manufacturers association, 2101 L St., N.W., Washington D.C., 20037, 1993. [2] JIRA publication, MIPS-94 standard, Japan industries association for radiation apparatus, 2-18-12 Yushima, Bunkyo, Tokyo, 113, Japan, 1995. (in Japanese) [3] H.K. Huang, et al., Asynchronous transfer mode technology for radiologic image communication, Am. J. Roentogenol. 64 (1995) 1533 – 1536. [4] A.J. Duerinckx, et al., Assessment of asynchronous transfer mode (ATM) networks for regional teleradiology, PACS design and evaluation, SPIE 2711 (1996) 61 – 70. [5] M. Kimura, S. Tani, New hospital information system at Hamamatsu university hospital, Innervision (in Japanese) 10 (7) (1995) 120 – 125. [6] S.M. Moore, Observations on DICOM demonstration at the RSNA annual meeting, PACS design and evaluation, SPIE 2711 (1996) 89 – 97.