Purpose: Morphological changes of affected arteries in intracranial artery dissection often occur in the acute phase. The usefulness of carotid ultrasonography (CU) to evaluate the changes is not well investigated. The purpose of this study was to assess the value of CU indexes to detect artery stenosis progression on magnetic resonance angiography (MRA).
Methods: This is a retrospective, single-center, observational study. We enrolled patients with intracranial vertebro-basilar artery dissection diagnosed based on criteria by the expert group (Debette S, et al: Lancet Neurol 2015) who were admitted within 30 days after onset from 2011 January to 2017 June. Carotid ultrasonography was performed on admission (median 0 days after onset) and follow-up (median, 40 days after onset; interquartile range, 11-106) to examined the flow velocity of both vertebral arteries. MRA was done on admission and follow-up just before or after the follow-up CU. Two stroke neurologists who were blinded to patients’ information assessed the change of vessel forms on MRA; stenosis progression was defined as an follow-up arterial diameter of <50% as compared to that at baseline on MRA. Patients were divided into two groups: those with stenosis progression (P group ) and the others (non-P group). Peak systolic velocity (PSV), end-diastolic velocity (EDV), mean velocity (MV) and pulsatility index (PI) were measured by CU and each baseline to follow-up ratio (follow-up/baseline) was compared between the two groups.
Result: Of 26 patients (11 women, 53±8 years old) who were enrolled, 10 (28%) showed stenosis progression (P group). The P group had lower EDV ratio (0.34±0.63 vs 1.05±0.39, P<0.01) and higher PI ratio (1.95±0.76 vs 0.85±0.30, P<0.01) than the non-P group. Using Receiver Operating Characteristic (ROC) curve analysis, the area under the curve (AUC) of EDV ratio to predict stenosis progression was 0.87 (P<0.01) with the cut-off value of 0.54, sensitivity of 87.5% and specificity of 93.3% and that of PI ratio was 0.93 (P<0.01) with 1.17, 88.9% and 82.3%, respectively.
Conclusion: Carotid ultrasonography is useful to predict the chrocnic stenosis progression of vertebra-basilar artery dissection.