Voxel-based histographic analysis of the basilar artery in patients with isolated pontine infarction

Background and Purpose: The signal information per voxels of magnetic resonance imaging (MRI) for vessel wall could reflect the pathologic features of atherosclerotic vessels. The aim of this study is to evaluate the usefulness of magnetic resonance voxel-based histogram (VBH) of atherosclerotic basilar artery in patients with isolated pontine infarctions (PIs). Materials and Methods: Wall and lumen of basilar artery were segmented from high resolution MR of 42 patients with isolated PI and 10 normal volunteers. VBHs were obtained after normalization by dividing the intensity of segmented wall with the intensity of non-infarcted area of pons. The variables of VBH included area (A), mean signal intensity (SI), standard deviation (SD), kurtosis (K), and skewness (SK) and area stenosis [AS; A^wall/(A^wall + A^lumen)] were compared according to the MRI-modified American Heart Association (AHA) atherosclerotic plaque schema, and between the subgroups of PI (lacunar: LPI and paramedian: PPI). Results: According to the MRI-modified AHA atherosclerotic plaque schema, A^wall/T₁ (mean area of wall on T₁-weighted MRI), SI^wall/T₁, SD^wall/T₁, SK^wall/T₁, K^wall/T₁, A^lumen/T₁, and AST₁ showed statistical differences. AHA IV–VII showed higher A^wall/T₁, SI^wall/T₁, and AST₁ than normal control. PPI showed statistical differences in A^wall/T₁, SI^wall/T₁, SK^wall/T₁, and A^wall/T₂ than those of normal control after post hoc test, whereas LPI in A^wall/T₁ and A^wall/T₂ (P < 0.05, Kruskal-Wallis test, Dunnett T3 procedure). Conclusions: VBH analysis can provide the quantitative information with regard to volume as well as composition of the atherosclerotic plaque in the basilar artery. The difference in patterns of VBH might be further useful in characterizing PIs with presumably different pathogenesis.