Yamada N, Higashi M, Otsubo R, Sakuma T, Oyama N, Tanaka R, Iihara K, Naritomi H, Minematsu K, Naito H
Department of Radiology, Cerebrovascular Division, National Cardiovascular Center, Osaka, Japan.
AJNR Am J Neuroradiol. 2007 Feb;28(2):287-92.
To investigate associations between cerebral ischemic events and signal hyperintensity in T1-weighted MR imaging (T1WI) of carotid plaque according to stenosis severity and to estimate persistence of T1WI signal hyperintensity.
A total of 222 patients (392 atherosclerotic carotid arteries) underwent plaque imaging using 3D inversion-recovery-based T1WI (magnetization-prepared rapid acquisition with gradient-echo [MPRAGE]). Carotid plaque with intensity on MPRAGE of >200% that of adjacent muscle was categorized as "high signal intensity" and correlated with ipsilateral ischemic events within the previous 6 months. A total of 58 arteries (35 patients) underwent repeat MR imaging a total of 70 times at a median interval of 279 days (range, 10-1037 days).
Ipsilateral ischemic events were more frequent in patients with MPRAGE high signals than in patients with low signals in the 0%-29%, 30%-69%, and 70%-99% stenosis groups: Relative risk (95% confidence interval) was 2.50 (0.96-6.51), 7.55 (1.84-31.04), and 1.98 (1.01-3.90), respectively. In the 70 cases of repeat MR imaging, 29 of 30 cases with high signals on the preceding MR imaging maintained high signals. Of the 58 arteries that underwent repeat MR imaging, 4 of 22 carotid arteries with high signals developed ipsilateral subsequent ischemic events within 1 year, whereas none with low signals developed subsequent events.
Carotid plaque signal hyperintensity on T1WI is strongly associated with previous ipsilateral ischemic events, persisting over a period of months, and may indicate risk of subsequent events. Larger clinical trials are warranted to clarify associations between signal hyperintensity and risk of subsequent cerebral ischemic events.
根据狭窄程度，研究脑缺血事件与颈动脉斑块T1加权磁共振成像（T1WI）信号高强化之间的关联，并评估T1WI信号高强化的持续情况。
共222例患者（392条动脉粥样硬化性颈动脉）接受了基于三维反转恢复的T1WI（磁化准备快速梯度回波采集[MPRAGE]）斑块成像。MPRAGE上强度大于相邻肌肉200%的颈动脉斑块被归类为“高信号强度”，并与前6个月内同侧缺血事件相关。共58条动脉（35例患者）进行了重复磁共振成像，共70次，中位间隔时间为279天（范围10 - 1037天）。
在0% - 29%、30% - 69%和70% - 99%狭窄组中，MPRAGE高信号患者同侧缺血事件比低信号患者更频繁：相对风险（95%置信区间）分别为2.50（0.96 - 6.51）、7.55（1.84 - 31.04）和1.98（1.01 - 3.90）。在70例重复磁共振成像中，前次磁共振成像显示高信号的30例中有29例维持高信号。在接受重复磁共振成像的58条动脉中，22条高信号颈动脉中有4条在1年内发生同侧后续缺血事件，而低信号者无后续事件发生。
T1WI上颈动脉斑块信号高强化与既往同侧缺血事件密切相关，持续数月，可能提示后续事件风险。需要更大规模的临床试验来阐明信号高强化与后续脑缺血事件风险之间的关联。
