Simultaneous Multiparametric Estimation of Arteriovenous Malformations Hemodynamics Using MR Fingerprinting ASL (MRF-ASL).

BACKGROUND AND PURPOSE

Accurate hemodynamic characterization of cerebral AVMs is critical for treatment planning, risk stratification, and post-treatment monitoring but remains challenging due to their abnormal angioarchitecture. MR-fingerprinting (MRF) arterial-spin-labeling (ASL) is a novel, non-invasive technique that enables simultaneous quantification of cerebral blood flow (CBF), arterial cerebral blood volume (aCBV), and bolus arrival time (BAT) within a single 5-minute scan. This study evaluates the feasibility of MRF-ASL in assessing AVM hemodynamics and compares its sensitivity for AVM detection with CBF measurements obtained using single-delay pseudo-continuous ASL (pCASL).

MATERIALS AND METHODS

Patients with DSA-confirmed AVMs were scanned on a 3T MRI system. Imaging protocols included MRFASL, standard single-delay pCASL, and T2-weighted MRI. MRF-ASL simultaneously derived CBF, aCBV, and BAT, with CBF estimated using two kinetic models: a one-compartment model, which reflects combined tissue and arterial contributions, and a two-compartment model, which separates arterial signal from tissue perfusion. ROIs were manually drawn over the AVM nidus and contralateral non-affected tissue. MRF-ASL parameters and pCASL-derived CBF were compared between the AVM nidus and non-affected tissue. Additionally, linear regression analyses were conducted to examine the relationships between MRF-ASL parameters, single-delay pCASL CBF, and the Spetzler-Martin (SM) grade.

RESULTS

Six AVM patients with SM grades ranging from 1 to 5 were included in this study. MRF-ASL parameters revealed significantly elevated CBF (AVM 129.3±21.5ml/100g/min vs. non-affected 51.6±23.9ml/100g/min, =0.03), CBF (AVM 109.8±24.4ml/100g/min vs. non-affected 36.6±18.6ml/100g/min, =0.03), aCBV (AVM 7.0±4.5% vs. non-affected 0.6±0.4%, =0.03), and shortened BAT (AVM 784±337ms vs. non-affected 1099±500ms, =0.03) in AVM nidus compared to contralateral non-affected tissue in the same patient. In contrast, no significant difference was observed for pCASL CBF (AVM 47.5±49.2ml/100g/min vs. non-affected 39.4±14.0ml/100g/min, =0.44). A significant positive correlation was identified between SM grade and both CBF (=0.006) and aCBV (=0.005). No association was found for CBF (=0.12), BAT (=0.15), or pCASL CBF (=0.13).

CONCLUSIONS

In our preliminary study, MRF-ASL has the potential to provide comprehensive and multiparametric evaluation of AVM hemodynamics, demonstrating superior sensitivity for detecting AVM abnormalities compared to single-delay pCASL. These findings show the feasibility of MRF-ASL as a potentially useful tool for non-invasive characterization and monitoring of AVMs.

ABBREVIATIONS

MRF = MR Fingerprinting; ASL = arterial spin labeling; pCASL = pseudo-continuous arterial spin labeling; aCBV = arterial cerebral blood volume; BAT = bolus arrival time; SM = Spetzler-Martin.