~(99m)Tc－ECD非侵襲的脳血流定量法（Brain Uptake Ratio）における入力関数の最適ROI設定位置の決定

摘要

Determination of the input function for the ~(99m)Tc-ethyl cysteinate dimmer brain uptake ratio (~(99m)Tc-ECD BUR) method as a non-invasive quantitative measurement of cerebral blood flow measurement is of critical importance in order to improve the accuracy of this method. The input functions were experimentally obtained by setting the regions of interest (ROIs) in the ascending aorta, aortic arch, and descending aorta on the 49 chest Rl-angio images. rCBFs by the BUR method with 3 input functions of the 6 cases were compared with those by the ~(123)I-iodoamphetamine (IMP) continuous arterial blood sampling method in order to determine the best location for the ROI of the input function. The input function of the ascending aorta was higher than those of the aortic arch and the descending aorta. The input functions of the aortic arch and the descending aorta decreased due to the origin of the three branches of the right brachiocephalic artery, left subclavian artery, and left common carotid artery. A good correlation was found in the regional cerebral blood flow (rCBF) values between the ~(123)I-IMP continuous arterial blood sampling method and the ~(99m)Tc-ECD BUR method with the input function of the ascending aorta. Therefore, the ascending aorta is the best location for the ROI of the input function for the ~(99m)Tc-ECD BUR method.%脳血流single photon emission computed tomography（SPECT）は，形態的診断に加えて，画像解析によって局所の血流量を算出する定量診断が可能であり，トレーサにはN-isopropyl-p（~(123)I）iodoamphetamine（~(123)I-IMP），~(99m)Tc-D，L-hexamethylene propyleneamine oxime（~(99m)Tc-HMPAO）および~(99m)Tc-ethyl cysteinate dimmer（~(99m)Tc-ECD）が広く用いられている.