Three-dimensional MRI analysis of individual volume of Lacunes in CADASIL

Three-dimensional MRI segmentation may be useful to better understand the physiopathology of lacunar infarctions. Using this technique, the distribution of lacunar infarctions volumes has been recently reported in patients with cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). Whether the volume of each lacune (individual lacunar volume [ILV]) is associated with the patients' other MRI lesions or vascular risk factors has never been investigated. The purpose of this study was to study the impact of age, vascular risk factors, and MRI markers on the ILV in a large cohort of patients with CADASIL.

Of 113 patients with CADASIL, 1568 lacunes were detected and ILV was estimated after automatic segmentation on 3-dimensional T1-weighted imaging. Relationships between ILV and age, blood pressure, cholesterol, diabetes, white matter hyperintensities load, number of cerebral microbleeds, apparent diffusion coefficient, brain parenchymal fraction, and mean and median of distribution of lacunes volumes at the patient level were investigated. We used random effect models to take into account intraindividual correlations.

The ILV varied from 4.28 to 1619 mm(3). ILV was not significantly correlated with age, vascular risk factors, or different MRI markers (white matter hyperintensity volume, cerebral microbleed number, mean apparent diffusion coefficient or brain parenchymal fraction). In contrast, ILV was positively correlated with the patients' mean and median of lacunar volume distribution (P=0.0001).

These results suggest that the ILV is not related to the associated cerebral lesions or to vascular risk factors in CADASIL, but that an individual predisposition may explain predominating small or predominating large lacunes among patients. Local anatomic factors or genetic factors may be involved in these variations.