The Significance of Vascular MR Contrast Enhancement in Carotid Stenosis

ABSTRACT

PURPOSE: To determine the significance of vascular MR contrast enhancement in carotid stenosis. MATERIALS AND METHODS: Forty patients that had angiographically proved carotid stenosis were selected for the study. A blind interpretation of vascular enhancement on an enhanced T1 weighted image, the lesion pattern on a DWI (diffusion weighted image), a perfusion defect on a MR perfusion image, the degree of stenosis, and collateral flow on cerebral DSA (digital subtraction angiography) was made by two observers, retrospectively. DWI lesion patterns were classified as having no high signal intensity, small PAI (perforating artery infarcts), large PAI, pial infarcts, territorial infarcts, and border zone infarcts. We evaluated the statistical correlation between vascular enhancement and the degree of stenosis, collateral flow, the DWI lesion pattern and the presence of a perfusion defect, respectively. RESULTS: The degree of carotid stenosis and the frequency of vascular enhancement correlated statistically (p=0.000). The presence of retrograde collateral flow on cerebral DSA and the border zone infarcts pattern on DWI were related with the occurrence of vascular enhancement (p=0.002, p=0.004). In 23 patients that underwent a MR perfusion study, the presence of a perfusion defect was also related to the occurrence of vascular enhancement (p=0.002). CONCLUSION: Vascular MR contrast enhancement may indicate a cerebral hypoperfusion in carotid stenosis.