Cortical vessel sign on susceptibility weighted imaging reveals clinically relevant hypoperfusion in internal carotid artery stenosis

•Asymmetric cortical vessel sign (ACVS) can be found in internal carotid artery (ICA) stenosis.•ACVS is associated with an increased volume of prolonged TTP and Tmax values.•It is an independent predictor of short term outcome.•ACVS can identify clinically relevant hypoperfusion in patients with ICA stenosis and contraindications for contrast agents.

Background and purposeInternal carotid artery (ICA) stenosis can lead to cerebral hypoperfusion and is a common cause of stroke. As susceptibility weighted imaging (SWI) has been used for penumbra imaging in acute ischemic stroke, we aimed at analyzing hypoperfusion using SWI in patients with ICA stenosis.Material and methodsClinical characteristics, asymmetric cortical vessel sign (more and/or larger, hypointense asymmetric cortical vessels) on SWI, Doppler sonography results and diffusion weighted imaging (DWI) lesion volume were retrospectively analyzed in patients with ICA stenosis. In a subgroup of patients, volume of prolonged time to peak and volume of prolonged time to peak of the residue curve (Tmax) were measured as reference standard. Outcome was assessed as modified Rankin score at discharge.Results104 patients were included. Median age was 72 and median degree of stenosis 70% according to NASCET. 13% had a asymmetric cortical vessel sign. These patients had a higher degree of stenosis (80% vs. 70%, p = 0.004), were more often symptomatic (93% vs. 61%, p = 0.020) and had higher DWI volume (7.3 ml vs. 0.2 ml, p = 0.011). Specificity for the prediction of DWI lesions was 86%. Also, patients with asymmetric cortical vessel sign had lower rates of favorable outcome (mRS = 0–2; 57% vs. 82%, p = 0.033) and volumes of Tmax ≥ 4 s, ≥6 s, ≥8 s, ≥10 s and TTP ≥ 2 s, ≥4 s, ≥6 s were significantly higher. In multivariate analysis, asymmetric cortical vessel sign was an independent negative predictor of favorable outcome (mRS 0–2; OR 0.184; CI [0.039; 0.875] p = 0.033).ConclusionIn patients with ICA stenosis, asymmetric cortical vessel sign is a sign of clinically relevant hypoperfusion.