Wu Max C, Gao Dong-Wei, Sievers Richard E, Lee Randall J, Hasegawa Bruce H, Dae Michael W
Department of Radiology, University of California, San Francisco, California, USA.
J Am Coll Cardiol. 2003 Aug 6;42(3):576-82. doi: 10.1016/s0735-1097(03)00716-2.
Although transgenic mice have emerged as powerful experimental models of cardiovascular disease, methods for in vivo phenotypic assessment and characterization remain limited, motivating the development of new instruments for biologic measurement.
We have developed a single-photon emission computed tomography system with a pinhole collimator (pinhole SPECT) for high-resolution cardiovascular imaging of mice. In this study, we describe a protocol for myocardial perfusion imaging of mice using technetium-99m ((99m)Tc)-sestamibi and demonstrate the feasibility for measurement of perfusion defect size from pinhole SPECT images.
Mice were anesthetized and injected with 370 MBq (10 mCi) of (99m)Tc-sestamibi. Tomographic projection images were acquired by rotating each mouse in a vertical axis in front of a stationary clinical scintillation camera equipped with a pinhole collimator. BALB/c mice (n = 15) were imaged after the permanent ligation of the left anterior descending coronary artery. The resulting defect size was measured from circumferential profiles of short-axis images. After imaging, the hearts were excised and sectioned to obtain ultra-high resolution digital autoradiographs of (99m)Tc-sestamibi, from which the actual infarct size was determined.
Reconstructed image quality was equivalent to that obtained for clinical myocardial perfusion imaging. Linear regression analysis produced a correlation coefficient of 0.83 (p < 0.001) between the measured and actual values of the defect size.
These results demonstrate that myocardial perfusion can be characterized qualitatively and quantitatively in mice using pinhole SPECT.
尽管转基因小鼠已成为心血管疾病强大的实验模型，但体内表型评估和表征方法仍然有限，这促使人们开发新的生物测量仪器。
我们已经开发了一种带有针孔准直器的单光子发射计算机断层扫描系统（针孔SPECT），用于小鼠的高分辨率心血管成像。在本研究中，我们描述了使用锝-99m（99mTc）-甲氧基异丁基异腈进行小鼠心肌灌注成像的方案，并证明了从针孔SPECT图像测量灌注缺损大小的可行性。
将小鼠麻醉并注射370 MBq（10 mCi）的99mTc-甲氧基异丁基异腈。通过在配备针孔准直器的固定临床闪烁相机前，使每只小鼠在垂直轴上旋转来获取断层投影图像。在左前降支冠状动脉永久结扎后，对BALB/c小鼠（n = 15）进行成像。从短轴图像的圆周轮廓测量所得的缺损大小。成像后，切除心脏并切片以获得99mTc-甲氧基异丁基异腈的超高分辨率数字放射自显影片，从中确定实际梗死面积。
重建图像质量与临床心肌灌注成像获得的质量相当。线性回归分析得出测量的缺损大小与实际值之间的相关系数为0.83（p < 0.001）。
这些结果表明，使用针孔SPECT可以对小鼠的心肌灌注进行定性和定量表征。
