Abruzzo T, Tumialan L, Chaalala C, Kim S, Guldberg R E, Lin A, Leach J, Khoury J C, Morgan A E, Cawley C M
Department of Radiology, University of Cincinnati Medical Center, Cincinnati, Ohio 45267-0762, USA.
Synapse. 2008 Aug;62(8):557-65. doi: 10.1002/syn.20511.
This study evaluates the utility and practical limitations of microcomputerized X-ray tomography (CT) as a research tool for examination of the cerebral circulation in mice. Six micro CT angiograms of the circle of Willis (COW) from six mice were obtained by scanning whole head and brain specimen perfused with a radio-opaque silicone contrast agent. Two-dimensional volume rendered images were postprocessed from three-dimensional image datasets using a partially automated high-throughput model that generated 10 surface projections for each specimen. The image processing model employed a straightforward global thresholding and computerized component labeling software algorithm. Postprocessed images were analyzed and results correlated with microdissection. Micro CT demonstration of COW vessels and their branch anatomy was assessed. 71% of COW vessels were completely demonstrated, 26% were partially demonstrated, and 3% were not demonstrated. All cases of nondemonstration and most cases of partial demonstration resulted from scan coverage or postprocessing clip error. Thresholding effect caused pseudostenosis of 8% of COW vessels and accounted for a minority of partial demonstration cases. No imaging artifacts were caused by contrast extravasation or ineffective contrast perfusion. Volume averaging caused minor angioarchitectural distortion of 58% of COW vessels. Ninety-five percent of COW > or =50 microm and 52% of COW vessels <50 microm were correctly identified by micro CT. Micro CT of the murine COW using a high-throughput image processing model is feasible. Angioarchitectural distortion due to volume averaging and thresholding effect can occur and pathological findings should be confirmed.
本研究评估了微型计算机断层扫描（CT）作为一种研究小鼠脑循环的工具的实用性及实际局限性。通过对灌注不透射线硅酮造影剂的全脑和脑标本进行扫描，获得了6只小鼠的6张 Willis 环（COW）微型CT血管造影图像。使用部分自动化的高通量模型从三维图像数据集中后处理二维容积再现图像，该模型为每个标本生成10个表面投影。图像处理模型采用了简单的全局阈值化和计算机化的组件标记软件算法。对后处理后的图像进行分析，并将结果与显微解剖进行关联。评估了COW血管及其分支解剖结构的微型CT显示情况。71%的COW血管得到了完整显示，26%部分显示，3%未显示。所有未显示的病例和大多数部分显示的病例均由扫描范围或后处理裁剪错误导致。阈值效应导致8%的COW血管出现假性狭窄，且在部分显示病例中占少数。未因造影剂外渗或造影剂灌注无效而产生成像伪影。容积平均导致58%的COW血管出现轻微的血管结构变形。微型CT能够正确识别95%直径≥50微米的COW血管和52%直径<50微米的COW血管。使用高通量图像处理模型对小鼠COW进行微型CT扫描是可行的。可能会出现因容积平均和阈值效应导致的血管结构变形，病理结果应予以确认。
