Kinoshita Noriyuki, Sugihara Hiroki, Adachi Yoshihiko, Nakamura Tomoki, Azuma Akihiro, Kohno Yoshio, Nakagawa Masao
Department of Cardiology, Kyoto First Red Cross Hospital, Japan.
Clin Nucl Med. 2002 Jan;27(1):34-9. doi: 10.1097/00003072-200201000-00008.
In myocardial perfusion imaging, multiple-vessel involvement of coronary artery disease (CAD) sometimes makes diagnosis difficult. Transient left ventricular (LV) dilatation on Tl-201 myocardial SPECT is a useful finding that enables the clinician to identify patients with multiple-vessel disease. The aim of this study was to confirm the utility of measuring transient LV dilatation for the detection of multiple-vessel CAD in exercise Tc-99m tetrofosmin myocardial SPECT. The participants were 55 CAD patients and 20 controls who underwent Tc-99m tetrofosmin myocardial SPECT exercise and resting imaging. During exercise, 370 MBq (10 mCi) Tc-99m tetrofosmin was injected. Exercise images were obtained 30 minutes after injection. At 210 minutes after injection, 740 MBq (20 mCi) Tc-99m tetrofosmin was administered intravenously. The rest SPECT images were acquired 30 minutes later. Thirty-six radii at every 10 degrees were generated from the center of short-axis images. An area surrounded by 36 maximal points of the myocardial Tc-99m tetrofosmin counts on each radius was calculated for exercise and rest images. The area surrounded by the 36 maximal points in the same slice of the exercise and rest images was assigned the variables A (Ex) and A(R), respectively. The transient dilatation index (TDI) of the left ventricle was calculated using the formula mean A (Ex)/A(R) in the apical, middle, and basal myocardial short-axis images. In the controls, the TDI was 0.970 +/- 0.021. In patients with CAD, the TDIs of one-vessel disease, two-vessel disease, and three-vessel disease were 1.034 +/- 0.032, 1.093 +/- 0.046, and 1.131 +/- 0.076, respectively. The TDIs were significantly greater in patients who had more occluded coronary arteries (P < 0.01). If the mean + 2SD of the TDI (1.012) in controls were assumed to be the normal upper limit, the sensitivity, specificity, and accuracy of this method in detecting two-vessel or three-vessel disease would be 91.4%, 76.9%, and 84%, respectively. The TDI is a useful index for evaluating subendocardial ischemia non-invasively and detecting multiple-vessel disease clinically.
在心肌灌注成像中，冠状动脉疾病（CAD）的多支血管受累有时会使诊断变得困难。铊-201心肌单光子发射计算机断层扫描（SPECT）上的短暂左心室（LV）扩张是一项有用的发现，可使临床医生识别多支血管病变的患者。本研究的目的是证实测量短暂左心室扩张在运动锝-99m替曲膦心肌SPECT中检测多支血管CAD的效用。参与者为55例CAD患者和20例对照者，他们接受了锝-99m替曲膦心肌SPECT运动和静息成像。运动期间，静脉注射370MBq（10mCi）锝-99m替曲膦。注射后30分钟获得运动图像。注射后210分钟，静脉注射740MBq（20mCi）锝-99m替曲膦。30分钟后采集静息SPECT图像。从短轴图像中心生成每10度的36条半径。计算运动和静息图像中每条半径上心肌锝-99m替曲膦计数的36个最大点所包围的面积。运动和静息图像同一切片中36个最大点所包围的面积分别指定为变量A（Ex）和A（R）。使用心尖、中间和基底心肌短轴图像中的公式平均A（Ex）/A（R）计算左心室的短暂扩张指数（TDI）。在对照组中，TDI为0.970±0.021。在CAD患者中，单支血管病变、双支血管病变和三支血管病变的TDI分别为1.034±0.032、1.093±0.046和1.131±0.076。冠状动脉闭塞较多的患者的TDI显著更高（P<0.01）。如果将对照组中TDI的平均值+2SD（1.012）假定为正常上限，则该方法检测双支或三支血管病变的敏感性、特异性和准确性分别为91.4%、76.9%和84%。TDI是一种用于无创评估心内膜下缺血和临床检测多支血管病变的有用指标。
