ObjectiveTo investigate the association between the imaging markers of ischemic cerebral small vessel disease and the occurrence of large hemispheric infarction (LHI).MethodsWe consecutively enrolled the patients with cerebral infarction in the middle cerebral artery blood supply area who admitted to the Department of Neurology, West China Hospital, Sichuan University between January 1st, 2015 and March 30th, 2016, and underwent head CT/MRI scans within one month of onset. LHI was defined as: the hypodensity was larger than 1/2 of the blood supply area of middle cerebral artery or more than 1/3 of the cerebral hemisphere within 6 hours on head CT at admission, or the infarction area was larger than 2/3 of the ipsilateral hemisphere on head MRI at admission. The basic clinical data and imaging data were collected, and the independent predictors of LHI and its independent correlation with ischemic cerebrovascular disease were explored by univariate and multivariate analyses.ResultsA total of 503 patients were included, 111 (22.1%) with LHI and 392 (77.9%) with non-LHI. Compared with the non-LHI patients, the LHI patients had a lower prevalence of white matter lesions, a lower Fazekas score, a lower prevalence of Fazekas score > 1, a lower prevalence of lacunae, a lower proportion of diabetes mellitus, a higher atrial fibrillation proportion of history, a shorter time from onset to treatment, a higher National Institute of Health Stroke Scale (NIHSS) score at admission, and a lower Glasgow Coma scale score; the distributions of TOAST types and locations of vascular stenosis were different (P<0.05). Multivariate analyses showed that white matter lesions [odds ratio (OR)=0.182, 95% confidence interval (CI) (0.050, 0.660), P=0.010], higher Fazekas score [OR=0.770, 95% CI (0.611, 0.970), P=0.027], and Fakazes score > 1 [OR=0.490, 95%CI (0.259, 0.928), P=0.029] were independent protective factors of LHI, while lacunae was not an independent factor of LHI [OR=0.583, 95% CI (0.265, 1.279), P=0.178]. Higher NIHSS score and history of atrial fibrillation were independent risk factors for LHI (P<0.001).ConclusionsThe occurrence and severity of white matter lesions (higher Fazekas score and Fazekas score > 1) are more in non-LHI group, and are independently related to the occurrence of LHI. The results suggest that ischemic preconditioning may have a protective effect on brain.