[en] The quality and limits of Tomomatic-64, an ECT equipment exclusive for cerebral blood flow examination, were studied. ¹³³Xe was used, and the machine was rotated at a scanning speed of 10 sec/360⁰. ECT images were resynthetized from data collected in a minute. Like other single photon ECTs, the spatial resolution decreased from the peripheral area toward the center, and the slice thickness was greater in the center. The sensitivity was inferior to the use of sup(99m)Tc, but was approximate. Thus, the present equipment was not inferior to other types. It differentiated small cylindrical images about 14 mm in diameter in the cold region and those smaller than 6 mm in the hot region. Morphologically, it easily differentiated images of 3 cm in diameter. (Chiba, N.)