偶发弥散加权成像 (DWI) 阳性皮质下和皮质病变，或急性偶发性脑微梗塞 (CMI) 是一种常见的脑缺血类型，在发生后约 2 周内可通过磁共振 DWI 检测到。研究发现，急性偶发性 CMI 在癌症患者中更为常见。急性偶发性 CMI 是否可以预测未来的缺血性中风尚不清楚。我们的目的是研究癌症患者急性偶发 CMI 与随后的缺血性中风或短暂性脑缺血发作 (TIA) 之间的关联。这是一项回顾性队列研究。我们使用代表超过一半以色列人口的 Clalit 健康服务记录来识别在 2014 年 1 月至 2020 年 4 月期间接受过脑部 MRI 的患有肺癌、乳腺癌、胰腺癌或结肠癌的成年人。我们纳入了在癌症发生前 1 年内接受过扫描的患者诊断和诊断后 1 年。主要结局是使用国际疾病分类第九版修订代码的缺血性卒中或 TIA。次要结局是颅内出血（ICH）和死亡率。记录从第一次 MRI 开始一直持续到主要结果、死亡或随访结束（2023 年 1 月）。使用 Cox 比例风险模型计算患有和不患有急性偶发性 CMI 的患者的风险比 (HR)，作为时间依赖性协变量。研究队列包括 1,618 名癌症患者，其中 59 名 (3.6%) 患有急性偶发性 CMI至少 1 次脑部 MRI 检查。从急性偶发性 CMI 到中风或 TIA 的中位时间（四分位距）为 26 天 (14-84)。多变量分析显示，与非 CMI 患者相比，急性偶发 CMI 患者的卒中或 TIA 风险较高（HR 2.97，95% CI 1.08-8.18，p = 0.035）。多变量分析后，急性偶发 CMI 也与死亡率相关（HR 2.76，95% CI 2.06-3.71，p < 0.001）；未发现与 ICH 相关。活动性癌症患者的脑 MRI 中急性偶发 CMI 与近期缺血性中风或 TIA 和死亡率的风险增加相关。这一发现可能表明，在癌症患者中随机检测到的急性偶发 CMI 可以指导初级脑血管风险预防和病因学检查。

Incidental diffuse-weighted imaging (DWI)-positive subcortical and cortical lesions, or acute incidental cerebral microinfarcts (CMIs), are a common type of brain ischemia, which can be detected on magnetic resonance DWI for approximately 2 weeks after occurrence. Acute incidental CMI was found to be more common in patients with cancer. Whether acute incidental CMI predicts future ischemic stroke is still unknown. We aimed to examine the association between acute incidental CMI in patients with cancer and subsequent ischemic stroke or transient ischemic attack (TIA).This is a retrospective cohort study. We used Clalit Health Services records, representing over half of the Israeli population, to identify adults with lung, breast, pancreatic, or colon cancer who underwent brain MRI between January 2014 and April 2020. We included patients who underwent scan between 1 year before cancer diagnosis and 1 year after diagnosis. Primary outcome was ischemic stroke or TIA using International Classification of Diseases, Ninth Revision codes. Secondary outcomes were intracranial hemorrhage (ICH) and mortality. Records were followed from first MRI until primary outcome, death, or end of follow-up (January 2023). Cox proportional hazards models were used to calculate hazard ratio (HR) for patients with and without acute incidental CMI, as a time-dependent covariate.The study cohort included 1,618 patients with cancer, among whom, 59 (3.6%) had acute incidental CMI on at least 1 brain MRI. The median (interquartile range) time from acute incidental CMI to stroke or TIA was 26 days (14-84). On multivariable analysis, patients with acute incidental CMI had a higher stroke or TIA risk (HR 2.97, 95% CI 1.08-8.18, p = 0.035) compared with their non-CMI counterparts. Acute incidental CMIs were also associated with mortality after multivariable analysis (HR 2.76, 95% CI 2.06-3.71, p < 0.001); no association with ICH was found.Acute incidental CMI on brain MRI in patients with active cancer is associated with an increased risk of near-future ischemic stroke or TIA and mortality. This finding might suggest that randomly detected acute incidental CMI in patients with cancer may guide primary cerebrovascular risk prevention and etiologic workup.