From the Departments of Radiology and Biomedical Imaging (C.Z., J.R.L., D.S., M.D.H.) and Surgery (W.G.), University of California, San Francisco, 4150 Clement St, San Francisco, CA 94121; and Department of Radiology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China (Y.W.).
Radiology. 2020 Mar;294(3):707-713. doi: 10.1148/radiol.2020191723. Epub 2020 Jan 28.
Background Intraluminal thrombus (ILT) within abdominal aortic aneurysms (AAAs) may be a potential marker for subsequent aneurysm growth. Purpose To investigate the role of ILT in AAA progression as assessed with CT and MRI. Materials and Methods This was a retrospective study, with patient data included from January 2004 to December 2018 at a Veteran Affairs medical center. Male patients with AAA who underwent contrast material-enhanced CT at baseline and CT or black-blood MRI at follow-up (minimal follow-up duration of 6 months) were included. The maximal AAA diameter was measured with multiplanar reconstruction, and the annual growth rate of aneurysms was calculated. Uni- and multivariable linear regression analyses were used to determine the relationship between demographic and imaging factors and aneurysm growth. Results A total of 225 patients (mean age, 72 years ± 9 [standard deviation]) were followed for a mean of 3.3 years ± 2.5. A total of 207 patients were followed up with CT, and 18 were followed up with MRI. At baseline, the median size of the AAA was 3.8 cm (interquartile range [IQR], 3.3-4.3 cm); 127 of 225 patients (54.7%) had ILT. When compared with AAAs without ILT, AAAs with ILT had larger baseline diameters (median, 4.1 cm [IQR, 3.6-4.8 cm] vs 3.4 cm [IQR, 3.2-3.9 cm]; < .001) and faster growth rates (median, 2.0 mm/y [IQR, 1.3-3.2 mm/y] vs 1.0 mm/y [IQR, 0.4-1.8 mm/y]; < .001). Small AAAs (size range, 3-4 cm) with ILT grew 1.9-fold faster than did those without ILT (median, 1.5 mm/y [IQR, 0.9-2.7 mm/y] vs 0.8 mm/y [IQR, 0.3-1.5 mm/y]; < .001). Medium AAAs (size range, 4-5 cm) with ILT had 1.2-fold faster growth than did those without ILT (median growth, 2.1 mm/y [IQR, 1.4, 3.7 mm/y] vs 1.8 mm/y [IQR, 0.9, 2.0 mm/y]; = .06). In multivariable analysis, baseline diameter and ILT were independently positively related to aneurysm growth rate (standardized regression coefficient, 0.43 [ < .001] and 0.15 [ = .02], respectively). Conclusion Both maximal cross-sectional aneurysm diameter and the presence of intraluminal thrombus are independent predictors of abdominal aortic aneurysm growth. © RSNA, 2020
背景 腹主动脉瘤（AAA）内的腔内血栓（ILT）可能是随后动脉瘤生长的潜在标志物。目的 研究 CT 和 MRI 评估的 ILT 在 AAA 进展中的作用。材料与方法 这是一项回顾性研究，纳入了 2004 年 1 月至 2018 年 12 月在退伍军人事务医疗中心的数据。纳入基线时接受对比增强 CT 检查、随访时接受 CT 或黑血 MRI 检查（随访时间至少 6 个月）的男性 AAA 患者。用多平面重建测量最大 AAA 直径，并计算动脉瘤的年增长率。采用单变量和多变量线性回归分析确定人口统计学和影像学因素与动脉瘤生长之间的关系。结果 共 225 例患者（平均年龄 72 岁±9[标准差]）平均随访 3.3 年±2.5 年。207 例患者接受 CT 随访，18 例接受 MRI 随访。基线时，AAA 的中位大小为 3.8 cm（四分位距[IQR]，3.3-4.3 cm）；225 例患者中有 127 例（54.7%）存在 ILT。与无 ILT 的 AAA 相比，有 ILT 的 AAA 基线直径更大（中位数，4.1 cm [IQR，3.6-4.8 cm] vs 3.4 cm [IQR，3.2-3.9 cm]；<.001），生长速度更快（中位数，2.0 mm/y [IQR，1.3-3.2 mm/y] vs 1.0 mm/y [IQR，0.4-1.8 mm/y]；<.001）。有 ILT 的小 AAA（大小范围，3-4 cm）的生长速度是无 ILT 的 1.9 倍（中位数，1.5 mm/y [IQR，0.9-2.7 mm/y] vs 0.8 mm/y [IQR，0.3-1.5 mm/y]；<.001）。有 ILT 的中等大小 AAA（大小范围，4-5 cm）的生长速度比无 ILT 的快 1.2 倍（中位数生长速度，2.1 mm/y [IQR，1.4，3.7 mm/y] vs 1.8 mm/y [IQR，0.9，2.0 mm/y]；=0.06）。多变量分析显示，基线直径和 ILT 与动脉瘤生长速度独立相关（标准化回归系数分别为 0.43[<.001]和 0.15[=0.02]）。结论 最大 AAA 横截面直径和腔内血栓的存在均是 AAA 生长的独立预测因子。 ©RSNA，2020
