Divisão de Cardiologia, Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
Arq Bras Cardiol. 2013 Jul;101(1):59-67. doi: 10.5935/abc.20130110.
Imaging techniques enable in vivo sequential assessment of the morphology and function of animal organs in experimental models. We developed a device for high-resolution single photon emission computed tomography (SPECT) imaging based on an adapted pinhole collimator.
To determine the accuracy of this system for quantification of myocardial infarct area in rats.
Thirteen male Wistar rats (250 g) underwent experimental myocardial infarction by occlusion of the left coronary artery. After 4 weeks, SPECT images were acquired 1.5 hours after intravenous injection of 555 MBq o f 99mTc-Sestamibi. The tomographic reconstruction was performed by using specially developed software based on the Maximum Likelihood algorithm. The analysis of the data included the correlation between the area of perfusion defects detected by scintigraphy and extent of myocardial fibrosis assessed by histology.
The images showed a high target organ/background ratio with adequate visualization of the left ventricular walls and cavity. All animals presenting infarction areas were correctly identified by the perfusion images. There was no difference of the infarct area as measured by SPECT (21.1 ± 21.2%) and by histology (21.7 ± 22.0%; p=0.45). There was a strong correlation between individual values of the area of infarction measured by these two methods.
The developed system presented adequate spatial resolution and high accuracy for the detection and quantification of myocardial infarction areas, consisting in a low cost and versatile option for high-resolution SPECT imaging of small rodents.
成像技术使我们能够在实验模型中对动物器官的形态和功能进行活体连续评估。我们开发了一种基于改进的针孔准直器的高分辨率单光子发射计算机断层扫描（SPECT）成像设备。
确定该系统在定量大鼠心肌梗死面积方面的准确性。
13 只雄性 Wistar 大鼠（250g）通过左冠状动脉阻塞进行实验性心肌梗死。4 周后，在静脉注射 555MBq 99mTc-Sestamibi 后 1.5 小时采集 SPECT 图像。断层重建是通过使用专门开发的基于最大似然算法的软件进行的。数据分析包括通过闪烁扫描检测的灌注缺陷面积与通过组织学评估的心肌纤维化程度之间的相关性。
图像显示出高目标器官/背景比，左心室壁和腔的可视化效果良好。所有存在梗死区域的动物均通过灌注图像正确识别。SPECT（21.1±21.2%）和组织学（21.7±22.0%）测量的梗死面积无差异（p=0.45）。这两种方法测量的梗死面积个体值之间存在很强的相关性。
所开发的系统具有足够的空间分辨率和检测和量化心肌梗死区域的高准确性，是一种用于小动物高分辨率 SPECT 成像的低成本、多功能选择。
