Department of Neurology, The University of Iowa Hospitals and Clinics, Iowa City, IA, USA.
Department of Radiology, The University of Iowa Hospitals and Clinics, Iowa City, IA, USA.
Interv Neuroradiol. 2023 Oct;29(5):532-539. doi: 10.1177/15910199221100619. Epub 2022 May 12.
Untreated brain aneurysms are usually surveilled with serial MR imaging and evaluated with 2D multiplanar measurements. The assessment of aneurysm growth may be more accurate with volumetric analysis. We evaluated the accuracy of a magnetic resonance angiography (MRA) segmentation pipeline for aneurysm volume measurement and surveillance.
A pipeline to determine aneurysm volume was developed and tested on two aneurysm phantoms imaged with time-of flight (TOF) MRA and 3D rotational angiography (3DRA). The accuracy of the pipeline was then evaluated by reconstructing 10 aneurysms imaged with contrast enhanced-MRA (CE-MRA) and 3DRA. This calibrated and refined post-processing pipeline was subsequently used to analyse aneurysms from our prospectively acquired database. Volume changes above the threshold of error were considered true volume changes. The accuracy of these measurements was analysed.
TOF-MRA reconstructions were not as accurate as CE-MRA reconstructions. When compared to 3DRA, CE-MRA underestimated aneurysm volume by 7.8% and did not accurately register the presence of blebs. Eighteen aneurysms (13 saccular and 5 fusiform) were analysed with the optimized 3D volume reconstruction pipeline, with a mean follow-up time of 11 months. Artifact accounted for 10.2% error in volume measurements using serial CE-MRA. When this margin of error was used to assess aneurysms volume in serial imaging with CE-MRA, only two fusiform aneurysms changed in volume. The variations in volume of these two fusiform aneurysms were caused by intra-mural and intrasaccular thrombosis.
CE-MRA and TOF-MRA 3D volume reconstructions may not register minor morphological changes such as the appearance of blebs. CE-MRA underestimates volume by 7.8% compared to 3DRA. Serial CE-MRA volume measurements had a larger margin of error of approximately 10.2%. MRA-based volumetric measurements may not be appropriate for aneurysm surveillance.
未经治疗的脑动脉瘤通常通过连续磁共振成像进行监测，并通过二维多平面测量进行评估。容积分析可能更能准确评估动脉瘤的生长。我们评估了磁共振血管造影（MRA）分割管道用于动脉瘤体积测量和监测的准确性。
开发了一种用于确定动脉瘤体积的管道，并在使用时间飞越（TOF）MRA 和 3D 旋转血管造影（3DRA）成像的两个动脉瘤模型上进行了测试。然后，通过重建使用对比增强-MRA（CE-MRA）和 3DRA 成像的 10 个动脉瘤来评估管道的准确性。随后，使用经过校准和改进的后处理管道分析我们前瞻性采集的数据库中的动脉瘤。超过误差阈值的体积变化被认为是真正的体积变化。分析了这些测量的准确性。
TOF-MRA 重建不如 CE-MRA 重建准确。与 3DRA 相比，CE-MRA 低估了动脉瘤体积 7.8%，并且不能准确登记 blebs 的存在。使用优化的 3D 体积重建管道分析了 18 个动脉瘤（13 个囊状和 5 个梭形），平均随访时间为 11 个月。使用连续 CE-MRA 进行体积测量时，伪影导致 10.2%的误差。当使用此误差幅度来评估 CE-MRA 连续成像中的动脉瘤体积时，只有两个梭形动脉瘤的体积发生变化。这两个梭形动脉瘤的体积变化是由壁内和囊内血栓形成引起的。
CE-MRA 和 TOF-MRA 3D 体积重建可能无法登记微小的形态变化，如 blebs 的出现。与 3DRA 相比，CE-MRA 低估了体积 7.8%。连续 CE-MRA 体积测量的误差幅度较大，约为 10.2%。基于 MRA 的体积测量可能不适合动脉瘤监测。
