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.
出处
《中国医学影像学杂志》
CSCD
2000年第2期136-138,共3页
Chinese Journal of Medical Imaging
关键词
离体心脏
在体心脏
心肌灌注显像
myocardial perfuslon imaging
~99mTc-MIBI
pig heart
in vivo
in vitro
