From the Image Sciences Institute (K.M.T., H.J.K.)
From the Image Sciences Institute (K.M.T., H.J.K.).
AJNR Am J Neuroradiol. 2021 Sep;42(9):1598-1603. doi: 10.3174/ajnr.A7186. Epub 2021 Jul 1.
Reliable and reproducible measurement of unruptured intracranial aneurysm growth is important for unruptured intracranial aneurysm rupture risk assessment. This study aimed to compare the reliability and reproducibility of 2D and 3D growth measurements of unruptured intracranial aneurysms.
2D height, width, and neck and 3D volume measurements of unruptured intracranial aneurysms on baseline and follow-up TOF-MRAs were performed by two observers. The reliability of individual 2D and 3D measurements and of change (growth) between paired scans was assessed (intraclass correlation coefficient) and stratified for aneurysm location. The smallest detectable change on 2D and 3D was determined. Proportions of growing aneurysms were compared, and Bland-Altman plots were created.
Seventy-two patients with 84 unruptured intracranial aneurysms were included. The interobserver reliability was good-to-excellent for individual measurements (intraclass correlation coefficient > 0.70), poor for 2D change (intraclass correlation coefficient < 0.5), and good for 3D change (intraclass correlation coefficient = 0.76). For both 2D and 3D, the reliability was location-dependent and worse for irregularly shaped aneurysms. The smallest detectable changes for 2D height, width, and neck and 3D volume measurements were 1.5 , 2.0, and 1.9 mm and 0.06 mL, respectively. The proportion of growing unruptured intracranial aneurysms decreased from 10% to 2%, depending on the definition of growth (1 mm or the smallest detectable changes for 2D and 3D).
The interobserver reliability of the size measurements of individual 2D and 3D unruptured intracranial aneurysms was good-to-excellent but lower for 2D and 3D growth measurements. For growth assessment, 3D measurements are more reliable than 2D measurements. The smallest detectable change for 2D measurements was larger than 1 mm, the current clinical definition of unruptured intracranial aneurysm growth.
可靠且可重复的未破裂颅内动脉瘤生长测量对于评估未破裂颅内动脉瘤破裂风险至关重要。本研究旨在比较二维（2D）和三维（3D）未破裂颅内动脉瘤生长测量的可靠性和可重复性。
由两位观察者对基线和随访时间飞越磁共振血管造影（TOF-MRA）上的未破裂颅内动脉瘤进行 2D 高度、宽度、颈部和 3D 体积测量。评估了个体 2D 和 3D 测量值以及配对扫描之间变化（生长）的可靠性（组内相关系数），并按动脉瘤位置进行分层。确定了 2D 和 3D 的最小可检测变化。比较了生长动脉瘤的比例，并绘制了 Bland-Altman 图。
共纳入 72 例患者的 84 个未破裂颅内动脉瘤。对于个体测量值，观察者间的可靠性为良好至极好（组内相关系数＞0.70），2D 变化的可靠性差（组内相关系数＜0.5），3D 变化的可靠性良好（组内相关系数=0.76）。对于 2D 和 3D，可靠性均取决于位置，且对于形状不规则的动脉瘤较差。2D 高度、宽度和颈部以及 3D 体积测量的最小可检测变化分别为 1.5、2.0 和 1.9mm 和 0.06mL。根据生长定义（1mm 或 2D 和 3D 的最小可检测变化），未破裂颅内动脉瘤的生长比例从 10%降至 2%。
个体 2D 和 3D 未破裂颅内动脉瘤大小测量的观察者间可靠性为良好至极好，但 2D 和 3D 生长测量的可靠性较低。对于生长评估，3D 测量比 2D 测量更可靠。2D 测量的最小可检测变化大于 1mm，这是当前未破裂颅内动脉瘤生长的临床定义。
