Intracranial Arteriovenous Shunting: Detection with Arterial Spin-Labeling and Susceptibility-Weighted Imaging Combined

Patient 62 with a complex developmental venous anomaly. ASL raw data (A) and right internal carotid artery angiogram, venous phase, lateral view (B). Increased signal-intensity is visible on ASL images within the right frontal lobe and deep brain nuclei (A, arrows). ASL images were considered suggestive of AVS by 1 blinded reader. Developmental venous anomaly was correctly diagnosed (and thus absence of AVS) by using SWI and a combination of SWI and ASL (not shown). DSA confirms the diagnosis of developmental venous anomaly by revealing a classic umbrella-shaped aspect at the venous phase with medullary veins (B, arrowheads) draining into an enlarged collector (B, arrows), which further drains into the superficial Sylvian vein and cavernous sinus.

A 60-year-old patient with a right paracentral AVM. ASL raw data (A) demonstrates a strong hypersignal at the anterior part of the right paracentral region (A, arrow). The slight venous hypersignal related to AVS was initially missed by the blinded readers by using SWI alone (B, arrowhead) but was correctly identified by using ASL and SWI combined (C, ASL/SWI merged image, arrow). Findings of time-resolved 4D contrast-enhanced MRA (D) were considered negative by the blinded readers. DSA reveals a small pial AVM in the right paracentral region (E, arrow).

A 52-year-old patient with a right cerebellar AVM draining into the right transverse sinus and the right periclival plexus. ASL raw data demonstrate a strong hypersignal within the right periclival plexus (A, arrows) and the right lateral sinus (B, arrowhead). With SWI alone, the slight venous hypersignal within the right periclival plexus and related to AVS was initially missed by the blinded readers (C, arrowhead) but correctly identified by using ASL and SWI combined (D, ASL/SWI merged image, arrow). Findings of time-resolved and high-resolution contrast-enhanced MRA were negative. Anteroposterior (E) and lateral (F) views from the right vertebral conventional angiograms show a small nidus (E, long arrow) draining into the right lateral sinus through the right superior petrosal sinus (E and F, arrowheads) and into the periclival plexus through a lateropontine vein (E and F, arrow).