3.RI断層画像構成とその評価 : シングルフォトンECT画像について(I.RI画像構成とその評価)(第37回総会)

抄録

Recently, a variety type of modalities for single photon emission CT (SP-ECT) has been in prevailed. Among them, we attempted to evaluated the 7-pinhole collimator tomography (7P-ECT) and the rotatingscinticamera emission CT (RS-ECT). The 7P-ECT method was proved to have several inherent problems due to the limited spatial sampling of 7 directions, and the nature of a pinhole collimator, which caused the distortion of reconstructed tomographic images with artifact, and the loss of resolution related to depth of objects. In this respect, intelligent use should be necessary. On the other hand, RS-ECT, which was consisted of 360°of data sampling, provided reliable reconstructed tomographic images with stable resolution in FWHM irrelevant to depth of objects. The quality of the tomographic images was proved greatly dependent on the amount of data accumulated. The detectable size of SOL in a liver phantom was 1.0 cm in diameter with the appropriated scintigraphic condition. Since the advantage SP-ECT over planar scintigraphy is to increase dimension from 2D to 3D without increase in radiation burden and, accordingly, to improve clinical efficacy, SP-ECT should be performed in addition to the conventional planar images as the screening study prior to X-ray CT.