Bryan R N, Cai J, Burke G, Hutchinson R G, Liao D, Toole J F, Dagher A P, Cooper L
Department of Radiology, The Johns Hopkins Medical Institutions, Baltimore, MD, USA.
AJNR Am J Neuroradiol. 1999 Aug;20(7):1273-80.
MR imaging has revealed putative evidence of subclinical cerebrovascular disease (CVD) as reflected by white matter signal changes and infarct-like lesions (ILLs). Nonetheless, the prevalence of this condition in the general population has been defined only to a limited extent. We herein report the prevalence and anatomic characteristics of ILLs seen on cranial MR images obtained as part of a population-based study of cardiovascular disease in middle-aged adults. These results are contrasted to those of previous similar studies, particularly those of an elderly population in the Cardiovascular Health Study (CHS).
This Atherosclerosis Risk in Communities (ARIC) cohort consists of a probability sample of community-living persons who were 55 to 72 years old at the time of MR examination. MR imaging of 1890 participants was performed at two ARIC field centers, based on a common protocol. MR studies were evaluated by trained readers at the MR Reading Center using original digital data displayed on a high-resolution workstation. The measures of lesion size, anatomic location, and signal intensity were collected. The definition for an ILL was a non-mass, hyperintense region with an arterial vascular distribution on spin-density and T2-weighted images.
Two hundred ninety participants had ILLs, for an overall prevalence of 15.3%. Eighty-two percent of participants with ILLs had lesions that were 3 mm or larger in maximal dimension, although 87% of these lesions were 20 mm or smaller in maximal dimension. The prevalence of ILLs increased with age, from 7.9% in the 55- to 59-year-old age group to 22.9% in the 65- to 72-year-old age group (P < .001). Lesion prevalence was greater in black (20.7%) than in white persons (10.2% [P < .0001]), but did not differ significantly between male and female participants. The basal ganglia and thalamic region was the most commonly affected anatomic site, accounting for 78.9% of the lesions.
Considering that the prevalence of self-reported stroke or transient ischemic attack in ARIC participants is 1.5%, these results suggest that there is significantly more subclinical than clinical CVD in the general population. Furthermore, the prevalence of this subclinical disease increases with age, and is greater in black persons. ILLs are dominated by "lacunae" in the basal ganglia and thalamus. These results are, in general, similar to those of a comparable study of elderly participants in the CHS, except for a 60% lower prevalence of ILLs in this younger population.
磁共振成像（MR成像）已揭示出白质信号改变和梗死样病变（ILLs）所反映的亚临床脑血管疾病（CVD）的假定证据。尽管如此，这种情况在普通人群中的患病率仅在有限程度上得到明确。我们在此报告在一项针对中年成年人的心血管疾病人群研究中所获得的头颅MR图像上ILLs的患病率及解剖学特征。将这些结果与先前类似研究的结果进行对比，特别是心血管健康研究（CHS）中针对老年人群的研究结果。
社区动脉粥样硬化风险（ARIC）队列由在进行MR检查时年龄为55至72岁的社区居住者的概率样本组成。1890名参与者的MR成像在两个ARIC现场中心按照通用方案进行。MR研究由MR阅读中心经过培训的阅片者使用在高分辨率工作站上显示的原始数字数据进行评估。收集病变大小、解剖位置和信号强度的测量数据。ILL的定义为在自旋密度和T2加权图像上具有动脉血管分布的非肿块性高信号区域。
290名参与者有ILLs，总体患病率为15.3%。ILLs参与者中有82%的病变最大直径为3毫米或更大，尽管这些病变中有87%的最大直径为20毫米或更小。ILLs的患病率随年龄增加，从55至59岁年龄组的7.9%增至65至72岁年龄组的22.9%（P <.001）。黑人的病变患病率（20.7%）高于白人（10.2% [P <.0001]），但男性和女性参与者之间无显著差异。基底神经节和丘脑区域是最常受累的解剖部位，占病变的78.9%。
鉴于ARIC参与者中自我报告的中风或短暂性脑缺血发作的患病率为1.5%，这些结果表明普通人群中亚临床CVD明显多于临床CVD。此外，这种亚临床疾病的患病率随年龄增加，且在黑人中更高。ILLs以基底神经节和丘脑的“腔隙”为主。总体而言，这些结果与CHS中针对老年参与者的类似研究结果相似，只是在这个较年轻人群中ILLs的患病率低60%。
