Susceptibility Vessel Sign in Deep Perforating Arteries in Patients with Recent Small Subcortical Infarcts.

OBJECTIVES: Recent small subcortical infarcts (RSSI) are considered an acute manifestation of cerebral small vessel disease. Paramagnetic signals in perforating arteries supplying RSSI may be detected on T2*-relaxation derived sequences on MRI and is defined as susceptibility vessel sign (SVS). We aimed to study the prevalence of SVS in patients with RSSI, and explore whether its identification is related to cerebral small vessel disease markers.

MATERIALS AND METHODS: We selected patients with RSSI identified on MRI during admission from a single-center stroke registry. The main demographic and clinical features, including vascular risk factors, were collected. Radiological features of RSSI and cerebral small vessel disease [white matter hyperintensities in deep and periventricular regions, enlarged perivascular spaces, lacunae, microbleeds, and brain atrophy] were described using validated qualitative scores. The presence of SVS was assessed on T2*gradient-echo or other susceptibility-weighted imaging. We compared the clinical and radiological features of patients with or without SVS in uni- and multivariate models.

RESULTS: Out of 210 patients with an RSSI on an MRI, 35 (17%) showed SVS. The proportion of SVS+ patients was similar in different susceptibility imaging modalities (p=.64). Risk factor profiles and clinical course were similar in SVS+ and SVS- patients. SVS+ patients had a higher grade of deep white matter hyperintensities and brain atrophy, more lacunae (p=.001, p=.034, p=.022, respectively), and a similar degree of the rest of radiological variables, compared to SVS- patients. In the multivariate analysis, the grade of deep white matter hyperintensities was the only independent factor associated with SVS [OR 3.1 (95% CI, 1.5-6.4)].

CONCLUSIONS: SVS in patients with RSSI is uncommon and related to a higher grade of deep white matter hyperintensities. Pathophysiological mechanisms underlying the deposition of hemosiderin in the path of occluded perforating arteries are uncertain and might include endothelial dysfunction or embolic mechanisms.