Fundamental and Clinical Study on Dynamic Single Photon Emission CT

动态单光子发射CT（SPECT）是使用SPECT系统与反复旋转相对的伽马相机。对三维功能成像技术的发展和临床应用进行了基础和临床研究。1.基础研究。从分辨率、灵敏度和均匀性等方面对数据采集和吸收校正方法进行了评价。通过模拟研究，估计了在数据采集过程中由于放射性的改变而产生的伪影对图像质量的影响。结果1.5%与10%的变化率，2.8%与30%的变化率，3.3%与50%的变化率表明伪影的影响不是图像质量的主要问题。2.临床研究。(1)三维脑血流功能成像：每30秒采集一次SPECT数据，按Kanno和Lassen提出的方法进行分析，得到脑血流断层图像。结果表明，这个m ...更多信息 该方法对X线CT所未见的轻度脑血管病的诊断及手术疗效的评价有一定的价值。(2)门控血池研究：使用Tc-99 m-RBC作为示踪剂获得门控血池SPECT数据。对重建图像进行旋转处理、右心室数据去除、断层数据求和和傅立叶分析，得到与左心室长轴平行或垂直的相位和振幅图像。在缺血性心脏病的诊断中，该方法特别适用于评价下壁和后壁的室壁运动异常。(3)Tc-99 m-PMT肝胆功能显像：以心脏的时间-活度曲线（TAC）为输入，肝脏各元素的TAC为输出函数，对1 min系列SPECT数据进行数学反卷积分析，构建有效血流和通过时间的功能图像。虽然正常人和肝硬化患者的总血流量和局部血流量与平均通过时间（MTT）均呈显著负相关，但也有部分患者局部血流量正常，MTT与总血流量减少呈负相关。(4)Tc-99 m-DTPA肾功能显像：采用同样的去卷积分析方法，分别对GFR和MTT进行功能显像。这些图像有助于区分MTT延长和GFR降低的局灶性疾病与MTT延长和GFR正常的局灶性疾病的病理生理。少

Dynamic single photon emission CT (SPECT) was performed using a SPECT system with repeatedly rotaing opposed gamma cameras. Fundamental and clinical studies were made on the development and clinical application of three dimensional functional imaging. 1. Fundamental study. Methods for data aquisition and absorption correction were evaluated in relation to resolution, sensitivity and uniformity. The effect of the artifact on the image quality, which is produced by the alteration of radioactivity during data collection, were estimated by a simulation study. The results of 1.5% with the alteration rate of 10%, 2.8% with the rate of 30%, 3.3% with the rate of 50% indicated that the effect of the artifact was not a major problem for image quality. 2. Clinical study. (1) Three dimensional cerebral blood flow functional imaging: SPECT data collected every 30 sec were analized by the method proposed by Kanno and Lassen to make tomographic images of cerebral blood flow. It was shown that this m … More ethod was usefull in the diagnosis of such mild cerebrovascular diseasesas not seen on X-ray CT and in the evaluation of the effect of surgical therapy. (2) Gated blood pool study: Gated blood pool SPECT data were aquired using Tc-99m-RBC as a tracer. Reconstructed images were processed by rotation of the images, removal of the data over right ventricle, summation of the tomographic data and Fourier analysis to obtain phase and amplitude images which are either paralled or perpendicular to long axis of left ventricle. In the diagnosis of ischemic heart disease, this method was particularly useful in the evaluation of wall motion abnormalities in inferior and posterior walls. (3) Tc-99m-PMT hepatobiliary functional imaging: One min serial SPECT data were analized by the mathematical deconvolution using time-activity curve (TAC) over the heart as input and TAC over each element of liver images as output function to construct functional images of effective blood flow and transit times. Although there were significant negative correlations between each of total and regional blood flow and mean transit time (MTT) in normals and cases with liver cirrhosis,there were some cases with normal regional blood flow and MTT against decreased total blood flow. (4) Tc-99m-DTPA renal functional imaging: Using the same method of deconvolution analysis, functional images of GFR and MTT were made. These images were useful in differentiating, pathophysiology of focal diseases with prolonged MTT and decreased GFR from those with prolonged MTT and normal GFR. Less