Utility of susceptibility-weighted imaging and arterial spin perfusion imaging in pediatric brain arteriovenous shunting.

INTRODUCTION: The objectives of the study are to investigate the application of susceptibility-weighted imaging (SWI) and arterial spin labeling (ASL) imaging in the assessment of shunting and the draining veins in pediatric patients with arteriovenous shunting and compare the utility of SWI and ASL with conventional MR and digital subtraction angiography (DSA).

METHODS: This study is a retrospective study of 19 pediatric patients with arteriovenous shunting on brain MRI who were also evaluated with DSA. We assessed the ability of conventional MRI sequences, susceptibility magnitude images, phase-filtered SWI images, and pulsed ASL images in the detection of arteriovenous (AV) shunting, number of draining veins and drainage pathways in comparison to DSA.

RESULTS: The mean number of detected draining veins on DSA (3.63) was significantly higher compared to SWI phase-filtered image (mean = 2.72), susceptibility magnitude image (mean = 2.92), ASL (mean = 1.76) and conventional MRI (2.47) (p < 0.05). Pairwise comparison of DSA difference scores (i.e., difference between MR modalities in the number of missed draining veins) revealed no difference between the MR modalities (p > 0.05). ASL was the only method that correctly identified superficial and deep venous drainage in all patients. Regarding detection of shunting, ASL, SWI phase-filtered, and magnitude images demonstrated shunting in 100, 83, and 84% of patients, respectively.

CONCLUSION: SWI depicts a higher number of draining vein compared to conventional MR pulse sequences. ASL is a sensitive approach in showing 100% sensitivity in the detection of AV shunting and in the diagnosis of the pattern of venous drainage. The present findings suggest the added utility of both SWI and ASL in the assessment of AV shunting.