Akiyama Y, Yui N, Kinoshita F, Koakutsu M, Tabushi K, Sakata S
Radioisotopes. 1982 Jun;31(6):297-301.
A multi-purpose gamma camera system which had 2 detectors of opposed position and was capable of radionuclide computed tomography (RCT) imaging was installed in Division of Nuclear Medicine, Chiba Cancer Center Hospital. In this study, the variance of RCT image due to the angular interval of sampling was analyzed. The full width at half maximum (FWHM) and full width at tenth maximum (FWTM) of point source were almost same for all sampling intervals investigated. The distortion of RCT images with uniform activity source could not be detected even for larger intervals. When the RCT images were obtained using a phantom contained 3 line sources and a bar phantom for RCT which were located at right angle with the plane of reconstruction, the images did not change between 1 degrees and 6 degrees of sampling interval, but for 9 degrees or more the distortion of images occurred explicity. For our system, sampling interval of 2 degrees was predicted from the theorectical calculation considering both resolution and statistical noise. But, results from the phantom studies of present work showed that sampling interval of 6 degrees was sufficient to reconstruct RCT images without distortion, and could be applicable to dynamic RCT images.
千叶癌症中心医院核医学科安装了一台多用途γ相机系统，该系统有两个相对位置的探测器，能够进行放射性核素计算机断层扫描（RCT）成像。在本研究中，分析了由于采样角度间隔导致的RCT图像方差。在所研究的所有采样间隔中，点源的半高宽（FWHM）和十分之一最大宽度（FWTM）几乎相同。即使对于较大的间隔，也未检测到具有均匀活性源的RCT图像的失真。当使用包含3个线源的体模和用于RCT的条形体模获得RCT图像时，这些体模与重建平面成直角放置，在1度至6度的采样间隔内图像没有变化，但对于9度或更大的间隔，图像明显出现失真。对于我们的系统，考虑分辨率和统计噪声，通过理论计算预测采样间隔为2度。但是，本研究的体模研究结果表明，6度的采样间隔足以重建无失真的RCT图像，并且可应用于动态RCT图像。
