[en] A 12 GeV proton synchrotron facility is being built at KEK (National Laboratory for High Energy Physics), Tsukuba, Ibaraki, Japan. The facility consists of a Cockcroft Walton's apparatus, a linear accelerator, a booster (a 500 MeV proton synchrotron), and the main ring. This report is described on the projected medical application of the booster together with brief review of the whole facility. Besides medical use, the booster is scheduled to be used for the study of neutron physics and meson experiments. Because the primary objective of this facility is the experimental study on elementary particles, a cooperative committee has been organized for the utilization of the booster for many other fields of applications. As for the medical use, diagnostical applications of the method of proton radiography based on proton absorption, and the method of pen drawing or line drawing based on the difference of multiple scattering are explained. The concrete facilities such as energy degrador, energy absorber, bending magnet, flattening filter, pipe collimater, and focusing magnet are explained. The neutron therapy based on the spallation reaction is also considered. The associated apparatuses such as neutron collimater, gamma-ray shutter, neutron monitor, and switching magnet are briefly explained. Finally, the application of π-mesons to the basic study of medical and biological sciences is discussed as future possibilities. (Aoki, K.)

[en] sup(99m)TcO₄ has been used most widely as a brain scan agent. In some instances however, sup(99m)Tc fails to demonstrate lesions which can be diagnosed with other radiopharmaceuticals. In order to compare the merits of ⁶⁷Ga and sup(99m)Tc, the authors used both agents for brain scanning in each of 25 patients who were randomly selected to participate in the study. Of the 25 cases 22 were histologically proven cases: 2 with brain abscesses (one of them associated with ventriculities), 8 with metastatic carcinoma, 4 with meningioma, 1 with meningosarcoma, 2 with acoustic neurinoma, and one case each of pituitary chromophobe adenoma, astrocytoma, oligodendroglioma, glioma and meningitis. Three cases, which were not verified histologically, were observed for up to one year following the initial study with no findings of aggravated central nervous pathology. Pragmatically Tc remains the agent for routine screening. When it was difficult to interpret a scan with sup(99m)Tc, the attributes of ⁶⁷Ga appeared to justify the additional effort, especially in the cases of meningioma, metastatic lesions and abscess. As reported before, ⁶⁷Ga is the scan of first choice for malignant lymphomas and postoperative assessment of brain tumors. (Evans, J.)

[en] We classified the left lateral view of the liver scan of liver cirrhosis into three image patterns. This view as well as anterior and posterior views was also a good position for estimation of the size of the left lobe of the liver and spleen. The diagnosis of liver cirrhosis was confirmed by laparoscopic diagnosis of nodular liver. The image pattern III was observed most frequently, the second was the pattern II and the last was the pattern I. In comparing pattern II with pattern III, it was noted that the cases of splenomegaly were observed more frequently in pattern II than in pattern III. It was also noted that in pattern III, the values of the zinc sulfate turbidity test were widely distributed; but in pattern II, about 50% of the cases revealed values over 20. We concluded that this view might be useful in the diagnosis of the severity of liver cirrhosis in some clinical cases. (auth.)

[en] Both fundamental and clinical studies of ¹¹¹In-BLM were performed. The in vivo stability of the complex was ascertained by thin-layer-chromatography of urine. The blood clearance, ratio of ¹¹¹In-BLM in plasma to that in whole blood, and cumulative excretion curves of urine and stool were studied. The blood clearance curve showed that the first half time was 16 minutes and that more than 90% of the administered activity was cleared from the circulating blood in two days. Ratios of plasma activity to the whole blood was almost constant 100 hours after injection. Urinary and fecal excretion showed that 80% of the administered activity was excreted in 24 hours, mainly in the urine (less than 1.0% in the feces). There appeared to be an inverse relationship between urinary and fecal excretion. The effective and biological half time of the liver, heart, bone marrow at the level of L₄ and spleen were obtained by counting the activity externally using probes located at each corresponding site. The activity in the bone marrow and heart had a rather short effective half time. The clinical usefulness of ¹¹¹In-BLM as a tumor imaging agent was evaluated in 19 patients, with 12 malignant and 7 benign lesions in Mitsui Memorial Hospital. Each study with ¹¹¹In-BLM was combined with ⁶⁷Ga-citrate scintigrams. A new method for comparative analyses of two radiopharmaceuticals without using a computer is reported here since comparative evaluation by the naked eye was difficult to make. Clinical experience to date seems to be encouraging to the detection of malignancy, although some benign tumors showed marked uptake of ¹¹¹In-BLM. (Evans, J.)

[en] The possibilities of synchrotron radiation coronary angiography (SR Cor. AG) for use in clinical fields were reviewed based on the results obtained using KEK. PF by diagnosis groups for 10 years. The Cor. AG examination was developed in U.S. and has been conducted mainly in the country at a frequency of ca. 10⁶ times/year. The incidence of complications was 1% and the mortality was only 0.2%. The method is characterized with its clear images of high S/N ratio, but it is an invasive treatment requiring high-grade techniques for the operator. The most important problem in its application is the deficiency of radiation dose. A candidate method substituting for SR Cor. AG is MRA (magnetic resonance angiography) which allows to make an image in a longitudinal direction, but the radiographic area is limited only in the coronary arterial origin and also the time needed for it is too long. Therefore, it is difficult to practically use MRA for clinical diagnosis. However, since a slender catheter was developed, IA SR Cor. AG became possible as an outpatient examination. Thus, we proposed to use this method for diagnosis of coronary heart diseases and introduced an equation expressing the effects of the subjects' positioning and the concentration of contrast medium. (M.N.)

[en] From March 1974 to May 1974, liver scintigraphies were performed at Mitsui Memorial Hospital. Three groups of patients were composed of: 24 of liver cirrhosis, 29 of chronic hepatitis and 30 of a normal control group. The mixture of 1.5 mCi of sup(99m)Tc-phytate and 30 μCi of ¹⁹⁸Au-colloid were injected rapidly. Ksub(L) value of sup(99m)Tc-phytate in the liver cirrhosis group was lower than the chronic hepatitis group, which was lower than the normal group. The correlation between Tsub(1/2) (L) and Tsub(1/2)(P): In the normal group, the coefficient correlation between Tsub(1/2)(L) and Tsub(1/2)(P) was fairly good both in sup(99m)Tc-phytate and in ¹⁹⁸Au-colloid, whereas the correlation was low in the chronic hepatitis group and liver cirrhosis group. The how correlation between the Ksub(L) values of sup(99m)Tc-phytate and ¹⁹⁸Au-colloid: The correlation of the Ksub(L) value was low in all three groups. Ksub(L) values in sup(99m)Tc-phytate were higher than they were in ¹⁹⁸Au-colloid in all three groups. When each probe was placed on the temporal and thigh region simultaneously for obtaining the peripheral blood clearance, the Tsub(1/2)(P) value (temporal) was always smaller than the Tsub(1/2)(P) value (thigh). Grade of kidney visualization in liver scintigraphy using sup(99m)Tc-phytate: Kidney activities were seen in 72.9% of 83 patients and there was no grade difference between the normal, chronic hepatitis and liver cirrhosis group. An additional attempt to determine the nature and size of ''sup(99m)Tc-phytate in vivo colloid'', Ca ion was added to sup(99m)Tc-phytate solution prior to the injection. Lung, spleen, and liver were simultaneously visualized using this ''in vitro sup(99m)Tc-phytate minicolloid''. (Evans, J.)

No abstract available

No abstract available

[en] Problems of angiography by digital radiography were reviewed with experimental results. Digital radiographic imaging, digitalization and preparation of time interval difference images were reviewed separately. Actual performance of digital subtraction anagiography (DSA) by the use of conventional X-ray equipment was described. Advantages and disadvantages of the method were mentioned, and its development into the diagnostic system was predicted. (Chiba, N.)

[en] Methods of measuring the volume of human organs, such as the brain, spleen, liver, kidneys and thyroid gland, using nuclear medical examinations such as single photon emission computed tomography and scintigraphy, x-ray CT, ultrasonography, and NMR-CT and their problems were outlined with a review of the literature. (Namekawa, K.)