Kale Sunita V, Alam Shah
Department of Radiology, Seth G.S. Medical College and K.E.M Hospital, Parel, Mumbai, Maharashtra, India.
Indian J Radiol Imaging. 2020 Apr-Jun;30(2):170-176. doi: 10.4103/ijri.IJRI_2_20. Epub 2020 Jul 13.
It is imperative to establish normative ranges of aortic diameter to diagnose various aortic pathologies. There have been very few studies establishing the normal aortic diameter on cross-sectional imaging, and none pertaining to the Indian pediatric population. The objective of this study was, therefore, to establish the normal effective diameter of thoracic aorta at multiple levels using computed tomographic data, calculate z-scores, and plot reference curves.
The effective thoracic aorta diameters (average of anteroposterior and lateral diameters) were measured at predefined levels (aortic root, ascending aorta at the level of right pulmonary artery, aortic arch, proximal descending aorta, and aorta at the level of diaphragmatic hiatus) on double-oblique reconstructed computed tomography (CT) images perpendicular to the direction of the vessel. Multiple functional forms relating the effective diameter to subjects' age were evaluated with least square regression methods, and further R was used to ascertain the best model. Age-based formulas to derive normal aorta diameters and mean squared errors (MSEs) were established.
Two hundred and seven contrast-enhanced CT (CECT) thorax studies of children without known cardiovascular disease were studied. The polynomial regression model relating the effective diameter that included linear, quadratic, and cubic age terms as independent variables were found to the best statistical model. The z scores were calculated, and normative curves were plotted.
We have established normative effective diameters of the thoracic aorta at multiple levels in Indian children of different age groups. Measurements outside of the normal ranges are indicators of ectasia, aneurysm, hypoplasia, or stenosis.
建立主动脉直径的正常范围对于诊断各种主动脉病变至关重要。很少有研究在横断面成像上确定正常主动脉直径，且尚无针对印度儿科人群的研究。因此，本研究的目的是利用计算机断层扫描数据确定胸主动脉多个层面的正常有效直径，计算z分数，并绘制参考曲线。
在垂直于血管方向的双斜重建计算机断层扫描（CT）图像上，于预定义层面（主动脉根部、右肺动脉水平的升主动脉、主动脉弓、降主动脉近端以及膈肌裂孔水平的主动脉）测量胸主动脉有效直径（前后径和横径的平均值）。采用最小二乘法回归评估有效直径与受试者年龄的多种函数形式，并进一步用R确定最佳模型。建立了基于年龄的公式以推导正常主动脉直径和均方误差（MSE）。
对207例无已知心血管疾病儿童的胸部增强CT（CECT）研究进行了分析。发现将有效直径与线性、二次和三次年龄项作为自变量的多项式回归模型是最佳统计模型。计算了z分数并绘制了正常曲线。
我们已确定了不同年龄组印度儿童胸主动脉多个层面的正常有效直径。超出正常范围的测量结果提示扩张、动脉瘤、发育不全或狭窄。
