MR Angiography for Detection of Pulmonary Arteriovenous Malformations in Patients with Hereditary Hemorrhagic Telangiectasia

Abstract

The purpose of our study was to evaluate contrast-enhanced MR angiography (CE-MRA) as a screening procedure for the detection of pulmonary arteriovenous malformations (AVMs) in patients with hereditary hemorrhagic telangiectasia (HTT). Two hundred three consecutive subjects (patients with diagnosed HHT or first-degree relatives; 87 males, 116 females; 6-83 years old) underwent pulmonary CE-MRA with 0.1 mmol/kg of gadobenate dimeglumine. The presence of pulmonary AVM was scored as 0 (none present), 1 (definitely present), or 2 (uncertain) and was evaluated by patient sex and pulmonary AVM size (< 5, 5-10, 11-15, 16-20, > 20 mm). Patients scored as 1 or 2 with at least one pulmonary AVM of > or = 5 mm underwent conventional pulmonary angiography for possible embolization. Pulmonary AVM detection on CE-MRA and pulmonary angiography was compared using paired Student's t tests. The presence of pulmonary AVM was considered definite in 56 of 203 (27.6%) patients and uncertain in one of 203 patients on CE-MRA. Of 156 pulmonary AVMs detected on CE-MRA, 124 (49 in 27 males, 75 in 30 females) were detected on first screening CE-MRA and 32 on follow-up CE-MRA. Pulmonary AVMs on CE-MRA were solitary in 25 patients, multiple in 31 patients, and predominantly small (< 5 mm, n = 32; 5-10 mm, n = 45). Significantly (p < 0.0001) fewer pulmonary AVMs were detected on pulmonary angiography (76/96 [79.2%] evaluable pulmonary AVMs in 40 patients before first pulmonary angiography; 92/119 [77.3%] pulmonary AVMs overall). Three-dimensional maximum-intensity-projection reconstructions permitted improved pulmonary AVM visualization and embolization planning of complex pulmonary AVMs. CE-MRA is suitable for screening patients with HHT. It permits accurate detection and staging of pulmonary AVMs, appropriate differentiation of lesions requiring embolization and accurate orientation, and visualization and planning of embolization therapy.