From the Department of Radiology (Y.J.), Wuhan General Hospital of the People's Liberation Army, Wuhan, China.
Departments of Radiology (Y.J., W.P., B.T., L.C., X.W., Q.L., J.L.).
AJNR Am J Neuroradiol. 2017 Sep;38(9):1716-1722. doi: 10.3174/ajnr.A5266. Epub 2017 Jul 6.
High-resolution 3T MR imaging can visualize intracranial atherosclerotic plaque. However, histologic validation is still lacking. This study aimed to evaluate the ability of 3T MR imaging to identify and quantitatively assess intracranial atherosclerotic plaque components ex vivo with histologic validation.
Fifty-three intracranial arterial specimens with atherosclerotic plaques from 20 cadavers were imaged by 3T MR imaging with T1, T2, and proton-density-weighted FSE and STIR sequences. The signal characteristics and areas of fibrous cap, lipid core, calcification, fibrous tissue, and healthy vessel wall were recorded on MR images and compared with histology. Fibrous cap thickness and maximum wall thickness were also quantified. The percentage of areas of the main plaque components, the ratio of fibrous cap thickness to maximum wall thickness, and plaque burden were calculated and compared.
The signal intensity of the lipid core was significantly lower than that of the fibrous cap on T2-weighted, proton-density, and STIR sequences ( < .01) and was comparable on T1-weighted sequences ( = 1.00). Optimal contrast between the lipid core and fibrous cap was found on T2-weighted images. Plaque component mean percentages were comparable between MR imaging and histology: fibrous component (81.86% ± 10.59% versus 81.87% ± 11.59%, = .999), lipid core (19.51% ± 10.76% versus 19.86% ± 11.56%, = .863), and fibrous cap (31.10% ± 11.28% versus 30.83% ± 8.51%, = .463). However, MR imaging overestimated mean calcification (9.68% ± 5.21% versus 8.83% ± 5.67%, = .030) and plaque burden (65.18% ± 9.01% versus 52.71% ± 14.58%, < .001).
Ex vivo 3T MR imaging can accurately identify and quantitatively assess intracranial atherosclerotic plaque components, providing a direct reference for in vivo intracranial plaque imaging.
高分辨率 3T MR 成像可显示颅内动脉粥样硬化斑块。然而，其组织学验证仍存在不足。本研究旨在通过组织学验证评估 3T MR 成像识别和定量评估颅内动脉粥样硬化斑块成分的能力。
20 例尸检颅内动脉粥样硬化斑块标本 53 例，行 3T MR 成像，采用 T1、T2、质子密度加权 FSE 和 STIR 序列。记录 MR 图像上纤维帽、脂质核心、钙化、纤维组织和健康血管壁的信号特征和面积，并与组织学进行比较。还对纤维帽厚度和最大管壁厚度进行了量化。计算并比较了主要斑块成分的面积百分比、纤维帽厚度与最大管壁厚度的比值以及斑块负荷。
脂质核心在 T2 加权、质子密度和 STIR 序列上的信号强度明显低于纤维帽（<.01），在 T1 加权序列上的信号强度相当（= 1.00）。在 T2 加权图像上，脂质核心与纤维帽之间的最佳对比。MR 成像与组织学之间的斑块成分平均百分比相当：纤维成分（81.86%±10.59%比 81.87%±11.59%，=.999），脂质核心（19.51%±10.76%比 19.86%±11.56%，=.863），纤维帽（31.10%±11.28%比 30.83%±8.51%，=.463）。然而，MR 成像高估了平均钙化（9.68%±5.21%比 8.83%±5.67%，=.030）和斑块负荷（65.18%±9.01%比 52.71%±14.58%，<.001）。
体外 3T MR 成像可准确识别和定量评估颅内动脉粥样硬化斑块成分，为体内颅内斑块成像提供直接参考。
