Arterial Spin-Labeling MR Imaging in the Detection of Intracranial Arteriovenous Malformations in Patients with Hereditary Hemorrhagic Telangiectasia

Abstract

Background and purpose: Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disease that causes vascular malformations in a variety of organs and tissues, including brain AVMs. Because brain AVMs have the potential to cause disabling or fatal intracranial hemorrhage, detection of these lesions before rupture is the goal of screening MR imaging/MRA examinations in patients with HHT. Prior studies have demonstrated superior sensitivity for HHT-related brain AVMs by using postcontrast MR imaging sequences as compared with MRA alone. We now present data regarding the incremental benefit of including arterial spin-labeling (ASL) perfusion sequences as part of MR imaging/MRA screening in patients with this condition.

Materials and methods: We retrospectively analyzed 831 patients at the UCSF Hereditary Hemorrhagic Telangiectasia Center of Excellence. Of these, 42 patients had complete MR imaging/MRA, ASL perfusion scans, and criterion-standard DSA data. Two neuroradiologists reviewed imaging studies and a third provided adjudication when needed.

Results: Eight patients had no brain AVMs detected on DSA. The remaining 34 patients had 57 brain AVMs on DSA. Of the 57 identified AVMs, 51 (89.5%) were detected on ASL and 43 (75.4%) were detected on conventional MR imaging/MRA sequences (P = .049), with 8 lesions detected on ASL perfusion but not on conventional MR imaging.

Conclusions: ASL provides increased sensitivity for brain AVMs in patients with HHT. Inclusion of ASL should be considered as part of comprehensive MR imaging/MRA screening protocols for institutions taking care of patients with HHT.

FIG 1.

Adult patient with genetically confirmed HHT and mild epistaxis, presenting for a screening brain MR imaging and MRA. A, Postprocessed ASL image with a focus of increased signal along the right superior frontal gyrus. B and C, Postgadolinium 3D BRAVO (3D brain volume) and noncontrast time-of-flight MRA, respectively, with no corresponding vascular abnormality demonstrated on these conventional MR imaging sequences. Frontal (D) and lateral (E) DSA images acquired from a selective right ICA injection in the late arterial phase demonstrating an ill-defined compact 12-mm AVM nidus (blue arrows) associated with early filling of a superficial cortical vein (yellow arrows) along the right superior frontal gyrus draining into the superior sagittal sinus.

FIG 2.

Teenage patient presenting with acute onset right hemiparesis and aphasia, found to have a large left frontoparietal hematoma with an associated vascular malformation suspicious for a ruptured AVM on noninvasive imaging. The patient was emergently taken to the operating room for decompressive hemicraniectomy and AVM resection. No preoperative angiogram was performed. Patient currently meets 1 of 4 Curacao criteria for HHT with genetic testing pending. However, given young age at presentation, clinical suspicion remained high for underlying HHT, because certain clinical manifestations such as epistaxis and oral/dermal telangiectasias, may not occur until later in life. A, ASL acquired on postoperative day 1 demonstrating a focus of increased signal along the left posterosuperior insula (blue arrow). Noncontrast time-of-flight MRA (B) and SWI (C) with expected postoperative changes in the operative bed, with no abnormality on MRA to suggest residual shunting. Frontal (D) and lateral (E) DSA images demonstrating abrupt cutoff/truncation of a posterior insular left M3 MCA branch (likely feeding artery) associated with a surgical clip, compatible with expected postoperative change. This finding corresponds to the focus of increased ASL signal and likely reflects arterial transit artifact as a result of postsurgical change rather than residual arteriovenous shunting. No residual AVM nidus or shunting was demonstrated. F, Preoperative CT angiogram demonstrating the left frontal AVM nidus in relation to the large acute left frontoparietal hematoma.