I MAGE MANAGEMENT and communication in medicine has made significant progress over the past 5 years in all major fronts: clinical, technological, and administrative. Technological development has been an integral part of medicine, and new imaging modalities have revolutionized diagnostic imaging and made significant impacts on the quality of patient care. These technological innovations, however, are creating an ever increasing amount of data to be presented to physicians and to be managed over a long period of time. The technical difficulties in the distribution and management of these complex diagnostic data are universal enough that there are no national boundaries. On the other hand, health care policy and professional practice of diagnostic imaging are different in different countries. The medical imaging sector of the computer application market is small compared to the rest of the computer industry. It is desirable for the medical community to be fully informed of technological advances so that medicine can take advantage of the technologies available in the large consumer and business markets. How, then, can the diagnostic imaging community implement image management and communication (IMAC) systems using international technology to meet the needs of many different clinical environment? The First International Conference on IMAC, which was organized in Washington, DC in June of 1989, was attended by 500 people representing 15countries. Experts and serious innovators from clinical, technological, and administrative disciplines participated in addressing wide ranging topics in IMAC. It also, for the first time, provided an opportunity to bring many international lMAC experts together for future collaboration. Since the first IMAC meeting, many new cooperative efforts and exchanges of ideas among the international participants have taken place. Especially for the large scale interna-

This paper describes an x‐ray K‐edge subtraction television system for noninvasive angiography utilizing synchrotron radiation. The phantom, including contrast material (iodine), is irradiated by monochromatized dual‐energy x‐ray flux, alternately, using a high speed monochromator. The monochromator consists of a silicon crystal plate vibrating at 15 Hz so that the phantom is irradiated by the x‐ray flux of 150 eV above and below the K‐edge photon energy of iodine, 15 times per second. As an x‐ray detector, TV cameras optically coupled to an x‐ray image intensifier are used and the video signal is processed to display the subtraction image of pairs of successive images in real time. This system was fully implemented and moving phantoms were examined. Both the time interval between the energy change and the exposure time of each image has been shortened to 2 ms.

Cystic lesions occurring in the submental and submandibular resions are frequently percutaneously palpable and present relatively minor difficulty to clinical diagnosis as cysts, but several supplementary methods of exploration such as computed tomography, echography, RI, and sialography, etc. are being used in order to accurately grasp its range, depth, and relationship to the surrounding tissues. However, each of these exploration methods has special characteristics and do not develop the complete information available beyond a single method of exploration. Recently, MRI has been highlighted as a diagnostic tool for obtaining images of high contrast. We have been applying magnetic resonance equipment, the MMI 150 S, manufactured by Mitsubishi Co. to 56 patients with diseases in the oral region since September, 1987. In the present paper, we report our findings on MRI data with some consideration for supplementary methods of diagnosis available in 2 patients with cysts in the submental and submandibular regions as shown in the follwing:In 2 patients with cysts as reported in the present paper, the morphology of the region with pathologic change was evidently depicted with markedly high intensity on T2 weighted images in qualitative terms, suggesting possible liquid content. The hyoid bone adjacent to the cyst was poorly depicted. Useful findings could be obtained for three-dimensional morphology and the positional relationship to the surrounding tissues by each tomographic image such as sagittal tomography, metopic tomography and horizontal tomography.

An X-ray K-edge subtraction television system utilizing synchrotron radiation is investigated. The phantom is irradiated by two monochromatized X-ray beams closely bracketing the K-absorption edge of iodine (33.17 keV) alternately, by means of a vibrating single crystal monochromator combined with a white synchrotron X-ray beam. The subtraction of the successive two images produced by these beams results in images that enhance signals arising from attenuation by iodine and suppresses signals by other materials. The prototype system is fully implemented using two kinds of real time image processing subsystems. The results are compared with those obtained by the conventional (nonreal time) processing system.

At present, several types of CT scanners are used in radiologic diagnostic field. Even if the tube voltage of X-ray is about 120 kV, X-ray energy distribution in every CT scanner may be different because of various X-ray filters used, geometrical conditions of data collection and etc. Therefore these performance is not shown as the same. In order to accurately diagnose lesions from normal images by the use of CT scanners, Japanese Committee for Evaluating Performance of CT Scanners recommended the standardization of how to measure CT scanner's performance and how to use several phantoms for these tests ; noise, contrast scale, spatial resolution (high and low), absorbed dose, size dependency of CT number. These two years and half, many advices and discussions as to performance gave us some points to be corrected and improved. These points containing tests and some results of low contrast resolution were reported. The phantoms of xyron-bar-in-xyron have no X-ray energy dependency of CT value.

Five hundred fifty-one new cases of non-Hodgkin's lymphoma were retrospectively studied with reference to histological classification, age incidence and survival. When examined according to the modified Rappaport classification, nodular lymphoma accounted for 14.9%, while diffuse lymphoma accounted for 82.9%. However, the frequency of nodular lymphoma differed among lymphomas of nodal, Waldeyer's and extranodal origin. Malignant lymphomas composed of large lymphoid cells were found to be common in Japan compared with Western countries, diffuse large lymphoid (DLL) lymphomas accounting for 47.4%, and nodular large lymphoid (NLL) lymphomas for 8.3%. The five-year survival rate according to histological classification was high in malignant lymphoma, diffuse well-differentiated lymphocytic (DWDL, 72%), nodular poorly differentiated lymphocytic (NPDL, 60%), nodular mixed PDL and large lymphoid (Nmix, 45%) and diffuse mixed PDL and large lymphoid (Dmix, 54%) lymphoma, but low in diffuse lymphoblastic (DLB, 10%), diffuse pleomorphic (Dpleo, 25%) and diffuse poorly differentiated lymphocytic (DPDL, 22%) lymphoma. The relationship between five-year survival and stage seemed to be close, although the last three types listed above were often found in advanced stages. The frequency of leukemic change was high in DLB (40%), DPDL (25%) and NPDL (20%) lymphoma. Radiation therapy proved effective in stages I and II cases, especially in Waldeyer's lymphoma. Chemotherapy provided better results in stages III and IV, although the rate of induction of complete remission was still unfavorable. The results of therapy were most favorable in patients given a combination of radiation therapy and chemotherapy.

Although the prime importance in treatment of head and neck cancer is eradication of tumors, due attention should be paid to the conservation of many important structures and functions in the region. Just to mention a few of these important human functions, there are phonation, digestion and facial expression. Simple surgical procedures specialized by otolaryngologists are no longer satisfactory. Recently, radiotherapy of head and neck cancer has developed to a superlative degree and chemotherapy to a practical degree although much still remains to be satisfied. Our aim was to organize an interdisciplinary group of specialists in surgery, radiotherapy and regional chemotherapy into a composite attack force. We aimed at most effective treatment with the least of side effects. Since 1961, our combined approach to cancer of the head and neck in close collaboration with radiotherapists has yielded much improved results. This has led to an increasing number of patients with satisfactory rehabilitation. 1. Cancer of the maxilla: Even in the advanced cases combined surgery, radiotherapy and regional chemotherapy has led to the preservation of important structures and functions. Many patients are now allowed to return to social life and to their previous jobs. 2. Cancer of the nasopharynx: Radiotherapy is the first choice. When the effect is less satisfactory, chemotherapy and a window-operation of the palate are performed. 3. Tumors of the tonsils: The majority of patients suffer from the reticulum cell sarcoma. Radiotherapy is the first choice. 4. Cancer of the larynx: A full dose of radiotherapy is the first choice. Partial resections are done when indicated. 5. Cancer of the tongue, hypopharynx and esophagus: Radiotherapy is the first choice in the majority of cases. Some need plastic surgery.