Introduction: Assessment of hemodynamics is of great importance for ensuing therapy strategy for intracranial avms. In this study, we calculated supply fraction from each feeding artery through vessel encoding arterial spin labeling (VE-ASL) which is a novel signal-to-noise ratio (SNR) efficient method for the mapping of vascular territories.
Methods: 6 patients diagnosed as intracranial AVMs via dsa are included. The main feeding artery of each AVM was decided by an experienced neurosurgeon. VE-ASL MR imaging was acquired with post labeling delay (PLD) time of 1s. Supply fraction of each voxel within the avm was calculated as the ratio of an individual arterial contribution to the total contribution and the corresponding curve graph was generated. Finally supply fraction of individual feeding artery was obtained. For the last patient, we set 3 PLD time points (1s, 1.3s, 1.6s) and estimated the supply fraction respectively. The data was analyzed using SPM8, MATLAB and SPSS.
Results: AVM lesions can be detected on perfusion images easily with obviously high CBF values. The supply fraction from individual feeding artery was successfully obtained (table 1). In 4 patients, the uppermost feeding artery decided by dsa is consistent with the supply fraction results. In the other 2 patients, it was hard to make a decision by dsa and the supply fraction results showed approximately equal values. In patient 6, there is no significant difference for the supply fraction among 3 PLD time points (P >0.01).
Conclusions: The contribution of each feeding artery to intracranial avm can be estimated by this new method and the results are consistent with that from dsa. Despite relaxation of labeled arterial blood water, the results are relatively stable from different PLD time points which indicate VE-ASL can be reliable for estimation of arterial supply fraction.
Patient Care: Knowing about the contribution of each feeding artery to the avm lesion may help clinicians to make more reasonable theraputic strategies and thus improve patient care.
Learning Objectives: By the conclusion of this session, participants should be able to get further konwledge about the hemodynamics of intracranial avm.
References: (1) Wong, EC, MRM, 58: 1086-1091, 2007.