ABSTRACT(english) in Medical Imaging Technology

Abstracts of Medical Imaging Technology of 1998.

January(Vol.16, No.1)

title	author	page
Dynamic Intravenous Coronary Angiography Using Synchrotron Radiation and its Clinical Application	Sadanori OHTSUKA, Yasuro SUGISHITA, Tohoru TAKEDA, Yuji ITAI, Kazuyuki HYODO, Masami ANDO	3
Key words : Intravenous coronary angiography, Synchrotron radiation
Abstract : Coronary artery disease is very popular and is a major cause of death, thereby its early diagnosis and proper management is an important clinical issue. The accurate diagnosis of coronary artery disease is made by coronary angiography(CAG). However, because CAG needs the injection of a contrast agent directly into a coronary artery, it is potentially hazardous and requires the patient's distress. So, we have developed a dynamic intravenous coronary angiography(IVCAG) by using synchrotron radiation(SR) as a less invasive and more convenient examination in place of CAG. We produce a wide monochromatic X-ray beam by reflecting SR beam with a silicon crystal and use it for the dynamic imaging. We have performed enough animal experiments in dogs and goat, then we applied it to the patients in May, 1996. We obtained the dynamic IVCAG and ascertained its usefulness in clinics. The dynamic IVCAG is convenient and will contribute as a screening and follow-up method for the coronary artery disease.

title	author	page
Assessing Coronary Angiography Using Synchrotron Radiation（SR）Where do we stand and What might be expected ?	Masayoshi AKISADA, Ken UEDA, Keiji UMETANI	10
Key words : Synchrotron radiation, Semi-selective coronary angiography, Energy subtraction, Above K edge energy radiography, Health economics.
Abstract : Coronary angiography using synchrotron radiation（SR Cor. AG）has seemed to reach the range of clinical availability of interdisciplinary or routine method emerging from sophisticated medical technology such as selective coronary angiography. Initial SR Cor. AG in animal experiments has been performed as follows; 1）energy subtraction angiography using iodine contrast media which was injected transvenously, 2）2-D detector by which serial images could be visualized in real time cine mode. The above experimental scheme has been changed to one shot, above K edge energy radiography using iodine contrast media which is injected into aortic root via catheter. Radiation exposure has been markedly decreased in the latter. Contrast media of Gadolinium is superior to iodine in reducing radiation exposure. SR Cor. AG is compared with selective coronary angiography literarily with respect technological routine and health economics.

January(Vol.16, No.5)

title	author	page
Telemedicine & Teleradiology	Takeo ISHIGAKI, azuhiro SHIMAMOTO, Katsuhiko KATO, Masanori TADOKORO, Tsuneo ISHIGUC	523
Key words:Telemedicine, Teleradiology, Image viewing stetion
Abstract : The current state and points of telemedicine and teleradiology are reported including the results and discussion of experimental teleradiology system at Nagoya University Hospital.

title	author	page
Telemedicine for the Support of Rural Health	Kazuya YOSHII,Hideki ITO, Sojiro MORITA, Isao TAKAHASHI	529
Key words: Telemedicine, Rural-Health, Rural-Health-Services
Abstract : Recent progress of computer and network system make telemedicine possible in daily use for health care. Geographically isolated general physicians occasionally can't decide whether they should send their patients to the hospital to make diagnosis or treatment. In these cases, if they can use the telemedicine to consult with a specialist, they can properly deal with these cases without leaving their clinic. The merits of telemedicine in rural areas has been shown to get rid of general physicians' anxiety, to improve the quality of health care, to ease the burden both of the patients and their family, to get rid of gaps among various areas, to provide the efficient medical service, to establish proper cooperation between rural clinic and hospital, to have post-graduate education, and to deal with the suit. In order to introduce the telemedicine to the area, it is necessary to have consensus of people, not to reduce the hours of usual consultation, not to have much confidence in technology and business, and to contribute the creative system both primary and secondary care physicians.

title	author	page
Telemedicine－Teleradiology in Kyoto	Yasutomi KINOSADA, Akihiro TAKADA, Tomoho MAEDA, Minoru HOSOBA	536
Key words : Telemedicine, Teleradiology, Computer Network, Web Technology, Clinical Evaluation
Abstract : The use of telemedicine has grown tremendously during the past few years. Teleradiology is one major application of telemedicine and expected as a tool to suppress the amount of national medical expenses and to improve radiological services at all sites on the network. Teleradiology is considered not to be in the academic stage but practical from a technical point of view at present in Japan. In this article, we are going to report on the teleradiology in Kyoto and the result of consequent clinical evaluations. We established the new multimedia teleradiology system, which provided the cooperative diagnostics by interchanging radiographic images bilaterally in real time during audio-visual discussion. Furthermore, the new diagnostic workstations were installed into our university hospital and the affiliated hospitals. A teleradiology link was also established between the university hospital and affiliated remote hospitals via ISDN for clinical evaluation of our system. The experiences have shown clearly that our teleradiology system is practicable and useful, and offers great potential to enhance the radiological diagnostic quality.

title	author	page
Telemedicine by Satelite Communication System and Mobile Earth Station	Masaomi TAKIZAWA	544
Key words: Telemedicine, Satellite, Image transmission, Mobile earth station
Abstract : Telemedicine using satellite communication based on mobile station are reported. The satellite communication system is useful way for the mobile stations, ships, mountain area and instead of ground telecommunication network at the developing countries. Telemedicine by the mobile screening system with high speed satel lite communication are not yet been reported. Some experimental system using high speed satellite communication and mobile CT system, an experiment of simulated emergency car with automatic navigation antenna system were described in the report.

＜Papers＞

title	author	page
Laser-Doppler Vibrometer/Velocimeter with the Single Cycle Phase Grating	Youhe LI, Shinichi TAMURA, Baocheng WANG	551
Key words: Grating, Amplitude grating, LDV, Diffraction
Abstract : This paper describes on improvement of measurement by using single cycle phase diffraction grating in LDV(Laser Doppler Velocimetry). First, we briefly explain basic theory and organization of LDV. Then, we go into details about the diffraction equation of the phase grating. The second, we compare this with the amplitude grating that is often used. Especially, application of the single cycle phase grating in the LDV system is examined. The last, it is shown in this paper that the output signal of intensity of the proposed system is twice as much as the conventional system and it is possible to discriminate movement direction of the object, and so on.

title	author	page
A Method for Analyzing Nuclei in the Glomeruli of Human Kidneys	Hong ZHU, Keiji TANIGUCHI, XiaoMang ZHANG, Yutaka NAKANO	559
Key words: Distribution of nucleus-size, Nuclei in glomerulus, Kidney tissues, Mesanginal cells, Overlapped nucleus regions
Abstract : The distribution of nuclei in the glomeruli must be the important information on diagnosis of renal illnesses. However, it is difficult to obtain the correct distribution for overlapped and noise effects of nuclei in them. By solving this problem, procedures for obtaining statistically the corrected distribution of the nucleus-size in the glomerulus images are proposed in this paper. These are as follows: (1) by applying a curve fitting technique for the size-histogram of nucleus regions, the normal distribution of non-overlapped regions is determined; (2) by assistance of statistical knowledge, the corrected distribution of the overlapped ones are estimated. Besides the distribution parameters describing states of renal diseases, i.e., mean value, variance, other parameters like the density and the relative area of the nuclei are also given in this system. The glomerulus images obtained from two groups of normal and abnormal test subjects are analyzed by using this method. As a result of analysis, it is found that the glomeruli in case of renal illnesses have a large amount of the mean value, variance, density and relative area of the nuclei. The phenomenon that renal illness results in larger variance can be observed only in the case that the distribution of overlapped nuclei are estimated.

title	author	page
3D Localizing Method for Ultyasound Endoscope by Outside-body Markers	Chen XIN, Shinichi TAMURA, Jiang KAI, Hiroaki NAITO, Hiroshi OTAWA, Hideo KAWAI, Yoshinobu SATO	569
Key words:Ultrasound image, Position marker,3D localization, Endoscope, Inside-body navigation
Abstract : In order to reduce the X-ray dose in the endoscopic examination and therapy, we are developing an inside-body navigation system which can give and visualize the direct 3D position of the tip and trace of the endoscope instead of the conventional 2D X-ray fluoroscopy. As a basic research for this objective, in this paper, we describe a method of identifying 3D position and direction of ultrasound scanning probe inserted into inside of the body, which gives endoscopic images. We use marker transducers placed on surface of the body, which transmit pulses synchronized to the ultrasound scanner. The method of measuring position ( direction and distance between scanning probe inside of body and transducer outside of boby ) of marker on the scanned image itself obtained with ultrasound endoscope by using adaptive threshold and robust algorithm is described. We also give some results of the experiments.

title	author	page
Detection of Pneumoconiosis Opacities on CT Images and Its Application to Automatic Diagnosis	Yoshihiro HAGIHARA, Hidefumi KOBATAKE, Hisao SHIDA	578
Key words: Automatic Diagnosis, Mathematical morphology, Pneumoconiosis, CT
Abstract : We propose an automatic diagnosis method of pneumoconiosis by extracting rounded opacities from chest CT images. It can meet the requirement better according to the ILO classification system whose categorization is based on the density of pneumoconiosis opacities. Profusion of small rounded and irregular opacities caused by pneumoconiosis is classified on 4 major categories based on the number of opacities per unit lung area. X-ray CT images give sectional images of human body. There are no overlapping between pneumoconiosis opacities, ribs and blood vessels. It is of great advantage from the viewpoint of image processing to realize automatic diagnosis system. This paper presents a fundamental approach of quantitative diagnosis of pneumoconiosis by detecting rounded opacities of pneumoconiosis on CT images. This method is based on mathematical morphology and consists of five processes. They are extraction of lung area, enhancement of rounded opacity candidates and vessels by morphological processing with multi-structuring elements, detection of rounded opacity, detection of vessels, and calculation of statistical values for quantitative diagnosis. Experiments showed that the correct classification rate on 12 categories was 83%. These results show the effectiveness of the proposed method.

January(Vol.16, No.6)

title	author	page
Telemedicine-Present and Future, and Issues	Hidenori SHINODA	603
Key words：Telemedicine, Information based society, IT based healthcare system, Individual focused system
Abstract : Communication technology was devoted to overcome the barrier of distance. Telemedicine was the way of overcoming the barrier of distance in delivering healthcare services. We are now in the information based society. Telemedicine is not only the way of delivering healthcare services to distant locations, but also the way of improving medical systems. In order to achieve this, we have to incorporate information technology (IT) with communication technology and build an individual focused healthcare system. In this system, individuals are well educated with medical knowledge and responsible to their health. Medical professionals are also well supported by healthcare information systems and can provide improved care to their patients on the basis of patients' electronic health records. Here, a model of future healthcare information system will be shown as the future of telemedicine system. And issues that have to be overcome will be discussed.

title	author	page
Medical Image Transmission for Various Telemedicine	Junji TSUTSUI, Kuniichi OZAWA, Tsukasa ASIHARA	610
Key words : Telemedicine, CATV line, ISDN line, B-ISDN line
Abstract : Various telemedicine systems using CATV line(Goshiki-cho, Hyogo pref.), ISDN line(Asahikawa City, Hokkai-do), B-ISDN line(Kyoto City, Kyoto pref.), are reported to show governmental general guidelines.

title	author	page
A Teleradiology System with Realtime and E-mail-based Operating Modes	Takanobu OSAKI, Hideyuki BAN, Hitoshi MATSUO, Akifumi OKABE	615
Key words : Telemedicine, Teleradiology, ISDN, E-mail
Abstract : We have developed a teleradiology system that supports two modes, a realtime mode and an e-mail-based mode. In the realtime mode, medical images and annotations are displayed simultaneously at a local site and a remote site. The display is synchronized by sending control messages generated by doctorﾕs operation. In the e-mail-based mode, the generated messages are sent to the remote site by e-mail along with the doctorﾕs voice narration. Each control message has a time stamp to synchronize it with the narration. The local doctor can thereby view the images and annotations and listen to the remote doctorﾕs diagnosis at a later time. A common user interface and an operating mode switching are supported by using the same control messages for the both operating modes. We have developed a PC-based prototype system and verified that a local doctor can view the images and pointer motions done by a remote doctor while listening to a synchronized voice narration by using the e-mail-based mode. We also verified that the local doctor can switch from the e-mail-based mode to the realtime mode without disturbing a diagnosis.

title	author	page
Development of Teleradiology System for Real Time Consultation	Minoru HOSOBA	622
Key words : Teleradiology, Realtime consultation, Multi-media workstation,Diagnostic Report,ISDN
Abstract : We have developed a Seamless Teleradiology system which supports real time consultation for remote clinics and image diagnosis inside a central hospital. The system has been installed to Kyoto Prefectural University of Medicine and clinically evaluated. The system consists of a multi-media image workstation for PACS and Teleradiology system to achieve real time diagnosis of remote site. The display processes developed as an application software in the workstation are connected by command packet transfered between two or more workstations through LAN or public telephone line(ISDN). When a connection is given, operations on the screen are sent as commands to the connected workstations, so the equivalent operations, such as windowing, magnification/ reduction of image, multi-frame display and file selection can be realized. Packet transfer is performed using the socket interface function of TCP/IP. In this system the video conference application is also used at the same time. To record the results of real time consultation as reports with reference images, the new reporting system has been developed. The reporting program is written in CGI running in the web server. The server can keep reports in HTML format and the browser on the client PC can easily access them. This system can be extended to rural medical cooperating system. In conclusion, image diagnosis inside a hospital, real-time consultation with a remote site and Web server type reporting system are enabled within the same application, which facilitates remote image diagnosis in central hospitals and have achieved favorable evaluation in the clinical field.

title	author	page
The way to Construct the Telemedicine System	Shinichi OKADA, Yuichiro YAMAMOTO, Atsushi OOKOSHI, Shin YAMAMOTO	630
Key words : Telemedicine,Teleradiology，System analisys
Abstract : There are many kinds of Telemedicine system. By its purpose,the Telemedicine sysytem is different in scale and in stile.In this paper we pick up two types of telemedicine system constructed by NEC corp.,that is "Toyonokuni computer assisted diagnostic system"and"Oriono remote diagnostic system". It is important to analize the requirement of the system.We explain the requirements of the system, system configration and the work folw by each system.

title	author	page
Medical Information and Image Database Management System for Telemedicine(MIMAS)	Atsushi KOIKE, Satoshi KATSUNO, Shuichi MATSUMOTO, Kazunori TAKEUCHI	636
Key words : words:Medical information, System, Telemedicine, WWW server, Interested region, Progressive image coding, Progressive display
Abstract : In this paper, we report a development of medical information and images database management system( MIMAS ) using WWW server on Internet to realize the remote medical communication system such as remote diagnosis application between major hospital and clinic, and diagnosis training for medical students or young doctors. And, various medical images and information can be easily shared and exchanged among several doctors and engaging people in medical field. The medical information system can be composed of WWW sever and image database server, and X-ray medical images and medical information can be stored. In addition to these basic functions, this system can provide a new image coding and transmitting scheme, and can only display interested region of image progressively with more fine resolution compared to other region by user.

＜Papers＞

title	author	page
Computer Assisted Breast Cancer Surgery Using 3D Ultrasonic Images	Masahiko NAKAMOTO, Yoshinobu SATO, Yasuhiro TAMAKI, Toshihiko SASAMA, Isao SAKITA, Yoshikazu NAKAJIMA, Shinichi TAMURA and Morito MONDEN	644
Key words :
Abstract : This paper describes an image guidance system for determining the optimal extent of surgical resection in breast-conservative cancer surgery. The accurate tumor localization is crucial for the determination of the extent so as to minimize the risk of a relapse and maximize breast conservation. First,3D tumor models are reconstructed from 3D ultrasonic images acquired just before the operation using an ultrasound probe to which a 3D position sensor is attached. Next, the 3D tumor models are superimposed onto live video images of a patient breast in order to enable the surgeon to perceive the exact 3D shape of the tumor, including complex tumor structures such as intraductal spread which cannot be examined by touch, as if it were visible through the breast skin. Therefore, the surgeon can determine the region for surgical resection in a more objective and accurate manner. The system is shown to be effective for the accurate tumor localization by experiments using phantom and clinical data.

title	author	page
Elimination of False-positive Candidates by Comparing Right and Left Mammograms in an Automated Mass Detection Algorithm	Satoshi KASAI, Hiroshi FUJITA, Takeshi HARA, Yuji HATANAKA and Tokiko ENDO	3
Key words :
Abstract : The purpose of this study is to improve our automated detection algorithm for masses on digital mammograms, in which the elimination of false positives can be performed by comparing right and left breasts in images. Our new scheme consists of the following eleven steps: (1) image digitization, (2) extraction of breast region, (3) image matrix reduction, (4) dynamic-range compression, (5) density gradient calculation, (6) classification and segmentation of breast region, (7) extraction of suspicious area, (8) re-analysis of detected candidates' region, (9) elimination of false positives by co-occurence matrix and gray level difference methods and elimination of liner-shape false-positive, (10) elimination of false positives by comparing right and left mammograms, and (11) annotated image display. In step (4), pixels in high density were transformed to lower ones by a transformed function being defined in each image. In step (10), false-positive candidates were eliminated by calculating some features based on pixel value and density gradient. The sensitivity of our revised detection algorithm was 87％ with 1.05 false positives per image in our database of 884 digitized clinical mammograms, which demonstrates the effectiveness of the proposed method.

title	author	page
Single-Exposure Low-Dose X-ray Imaging with Grid-Less and Grid (GLG) Imaging Plates: a Kalman-Filter Approach	Reza Aghaeizadeh ZOROOFI, Yuji OGATA, Hisashi TAKETANI, Yoshinobu SATO, Shinichi TAMURA, Kazuo INAMOTO, Shinji SHIMOJO	667
Key words : X-ray imaging, Scattering, Kalman-filter, Recursive restoration, Deconvolution
Abstract : The present study was designed to monitor novel ideas in the acquisition and manipulation of data in an X-ray imaging system. A grid was sandwiched between two cascaded imaging plates (IPs). Using a fan-beam X-ray tube and a single exposure scheme, the two IPs, respectively, recorded grid-less and grid (GLG) type information of the object. Referring to the mathematical model of the GLG technique, it was explained that the collected data associated with the grid-less IP was of high (S/N) together with large scattered components whereas that of IP with grid was of low (S/N) and suppressed scattered components. Based on this assumption and using a Gaussian convolution kernel representing the effect of scattering, a technique was proposed to estimate scatter parameters of the GLG plates. Then, a Kalman-filter was developed to restore noisy-blurred images of the GLG techniques using the IPs data and estimated parameters. The results are shown for both the computer simulated and real X-ray phantom data.