心肌灌注显像放射性稀疏区成因与组织衰减的实验研究  

Experimental Study of Tissue Attenuation and Causes of "Defect" on Myocardial Perfusion Imaging

作　　者：范义湘[1] 郑普德[1] 彭武和[1] 陈仰珍[1] 石卫民 周乃基 

机构地区：[1]第一军医大学南方医院核医学科,广州510515 [2]第一军医大学南方医院放疗中心,广州510515 [3]中国人民解放军187医院核医学科,海口571159

出　　处：《中国医学影像学杂志》2000年第2期136-138,共3页Chinese Journal of Medical Imaging

摘　　要：目的：探讨正常心肌灌注显像放射性稀疏区的成因。材料与方法：对５例猪心行~９９ｍＴｃ－ＭＩＢＩ在体和离体心肌灌注显像，并用ＲＯＩ技术测量左室各部位心肌的放射性水平（计数／像元），由该值在两种状态下的差值计算衰减程度（％）。结果：两种状态间壁后部和后壁放射性水平最低；在体心肌前壁中段衰减程度（７．９％）高于其前段和后段，该区衰减程度与胸壁厚度呈正相关；后壁衰减程度最高（１１．９％）。结论：胸壁是造成前壁中段稀疏影的原因，隔肌是形成后壁稀疏影的重要原因之一。心肌图像重建时可根据衰减程度作适当补偿。Purpose: To investigate image features and causes of radioaclivc 'defect' regions on normal myocardial perfusion imaging. Materials and Methods: 5 pig hearts underwent myocardial perfusion imaging in vivo and in vitro using ~99mTc-MIBI. The counts per pixel in each segment of left ventricle was measured and the count difference between in vivo and in vitro images was calculated. Results: In vivo study revealed defect regions on midpart of anterior wall, basal part of sepia and posterior wall. In vitro study of the same hearts showed no defect at midpart of anterior. Although defects still existed in posterior wall, the defect was smaller. Quantitative analyses showed that the lowest radioactivity existed on hasal sepia and posterior wall in both imaging methods. 'The attenuation from soft tissue of chest wall causes 7. 9 % count loss at anterior midpart which was greater than that at ante and hasal segments; the greatest attenuation, averaging 11. 9 %, was found at posterior wall. Conclusions: Chest wall is responsible to the defect noted in vivo at anterior midpiece, and diaphragm is a chief cause of decrease of count at posterior wall. Proper compensation for count loss at those regions should be made according to the extent of attenuation to improve the accuracy of myocandial perfusion imaging.

关 键 词：离体心脏 在体心脏 心肌灌注显像 

分 类 号：R816.2[医药卫生—放射医学]