Department of Radiology, Centre Hospitalier Universitaire de Montréal and CHUM Research Center, University of Montreal, 1560 Sherbrooke Est, H2L 4M1 Montréal, Québec, Canada.
Eur J Radiol. 2012 Aug;81(8):1688-94. doi: 10.1016/j.ejrad.2011.04.044. Epub 2011 May 20.
To validate the reproducibility and accuracy of a software dedicated to measure abdominal aortic aneurysm (AAA) diameter, volume and growth over time.
A software enabling AAA segmentation, diameter and volume measurement on computed tomography angiography (CTA) was tested. Validation was conducted in 28 patients with an AAA having 2 consecutive CTA examinations. The segmentation was performed twice by a senior radiologist and once by 3 medical students on all 56 CTAs. Intra and inter-observer reproducibility of D-max and volumes values were calculated by intraclass correlation coefficient (ICC). Systematic errors were evaluated by Bland-Altman analysis. Differences in D-max and volume growth were compared with paired Student's t-tests.
Mean D-max and volume were 49.6±6.2mm and 117.2±36.2ml for baseline and 53.6±7.9mm and 139.6±56.3ml for follow-up studies. Volume growth (17.3%) was higher than D-max progression (8.0%) between baseline and follow-up examinations (p<.0001). For the senior radiologist, intra-observer ICC of D-max and volume measurements were respectively estimated at 0.997 (≥0.991) and 1.000 (≥0.999). Overall inter-observer ICC of D-max and volume measurements were respectively estimated at 0.995 (0.990-0.997) and 0.999 (>0.999). Bland-Altman analysis showed excellent inter-reader agreement with a repeatability coefficient <3mm for D-max, <7% for relative D-max growth, <6ml for volume and <6% for relative volume growth.
Software AAA volume measurements were more sensitive than AAA D-max to detect AAA growth while providing an equivalent and high reproducibility.
验证一款专门用于测量腹主动脉瘤（AAA）直径、体积和随时间增长的软件的可重复性和准确性。
测试了一款能够对 CT 血管造影（CTA）进行 AAA 分割、直径和体积测量的软件。在 28 例连续两次 CTA 检查的 AAA 患者中进行了验证。56 次 CTA 的所有图像均由一位资深放射科医生进行两次分割，由三位医学学生进行一次分割。通过组内相关系数（ICC）计算 D-max 和体积值的内部和观察者间可重复性。通过 Bland-Altman 分析评估系统误差。使用配对学生 t 检验比较 D-max 和体积增长率的差异。
基线时 D-max 和体积平均值分别为 49.6±6.2mm 和 117.2±36.2ml，随访时分别为 53.6±7.9mm 和 139.6±56.3ml。基线和随访检查之间，体积增长率（17.3%）高于 D-max 进展率（8.0%）（p<.0001）。对于资深放射科医生，D-max 和体积测量的内部观察者 ICC 分别估计为 0.997（≥0.991）和 1.000（≥0.999）。D-max 和体积测量的总体观察者间 ICC 分别估计为 0.995（0.990-0.997）和 0.999（>0.999）。Bland-Altman 分析显示，D-max 的重复性系数<3mm、相对 D-max 增长率<7%、体积<6ml、相对体积增长率<6%，表明观察者间具有极好的一致性。
与 D-max 相比，软件 AAA 体积测量对 AAA 生长的检测更敏感，同时提供了等效的高可重复性。
