Clinical application in superposing the image of ECT on x-ray CT, and planning the multi-purpose gamma-camera for ECT

Superposing the images of ECT on x-ray CT and development of a new γ-camera for this purpose were studied. As for ECT, LEOV γ-camera (Searle) was used, and the reconstruction of the images was carried out by filtered back projection method. CT/T8800 (GE) was applied for x-ray CT. The outlines of organs by x-ray CT were superposed on the magnified images of ECT taken at the same plane. Out of 20 cases inspected, hyperthyroidism and primary lung cancer with metastasis of lymph nodes, which were diagnosed by this method were introduced. For ECT, sup(99m)Tc-pertechnetate was used for the former cases; in the latter case, sup(99m)Tc-MAA and 67Ga-citrate were used. In order to reduce the difficulties due to the different position of the patient in ECT and x-ray CT, a new γ-camera (GCA 401-5, Toshiba Co.) with a rolling gantry around the spine-positioned patient was developed. The new device enables to adjust the slices of ECT to those of x-ray CT. (Nakanishi, T.)