Abstract WP96: Quantitative Imaging Markers On Vessel Wall Magnetic Resonance Imaging Correlate With Disease Activity And Treatment Response In Cerebral Vasculopathies

Abstract

Introduction: Little is known about the utility of vessel wall magnetic resonance imaging (VWMRI) in assessing treatment response in various inflammatory and non-inflammatory intracranial vasculopathies, and if there is any correlation of vessel wall enhancement (VWE) with disease activity. We aimed to quantitatively investigate the differences in VWE patterns on follow-up VWMRI in patients with primary CNS vasculitis (PCNSV), secondary CNS vasculitis (SCNSV) and intracranial atherosclerotic disease (ICAD). Methods: VWMRI scans of patients with a confirmed diagnosis of either PCNSV, SCNSV or ICAD presenting to our tertiary care center between January 2015 and January 2021 were reviewed. Inclusion criteria were age greater than 18 years and at least 2 VWMRI scans available, including one from time of first clinical presentation with active disease. For each patient, 20 arterial segments were evaluated on VWMRI for the presence of VWE and the total number of enhancing arterial segments were reported. Percent concentricity, median number of enhancing arterial segments (MEAS) and percent change in MEAS was calculated and compared across all 3 diagnoses. Results: A total of 28 patients met study inclusion criteria (median age 47, 43% male) and had a diagnosis of either PCNSV (n=6), SCNSV (n=7) or ICAD (n=15). Median time to follow-up VWMRI was 22, 20 & 11 weeks for PCNSV, SCNSV & ICAD respectively. On initial VWMRI, the MEAS was 7 for each PCNSV & SCNSV and 6 for ICAD. Higher percent concentricity of VWE was seen more with PCNSV (92.3%) and SCNSV (71.4%) compared to ICAD (22.2%). All (100%) patients with PCNSV and 2 (33%) patients with SCNSV were treated with immunosuppression whereas 3 (50%) patients with SCNSV were treated with antimicrobials. All patients with PCNSV and SCNSV improved clinically whereas those with ICAD progressed or remained stable. The MEAS on follow up VWMRI decreased with treatment in patients with PCNSV (43% decrease) and SCNSV (14% decrease) but increased in those with ICAD (16% increase) and correlated clinically with disease activity and treatment response. Conclusion: Percent concentricity and MEAS on VWMRI may be useful non-invasive markers to monitor disease activity & treatment response in patients with intracranial vasculopathies.