All of the data published in the literature show that MR is more sensitive than CT in diagnosing cerebral ischemic lesions. This greater sensitivity is due to its ability to detect even the minimal changes in tissue water content which occur in the early phases of the infarct. The literature concerning the use of MR in lacunar lesions is extremely limited but agrees with the general data regarding ischemia. However, there is some doubt that the thickness of the strata of CT and the interval between the strata of MR could have an influence on their ability to detect very small lesions. Modifications in the sensitivity of MR in detecting ischemic lesions are now well known: during the acute phase, the T2 images are more sensitive, while in the subacute and chronic phase both T1 and T2 have the same diagnostic capability.