CT angiography findings of pulmonary arteriovenous malformations in children and young adults with hereditary hemorrhagic telangiectasia

OBJECTIVE: The purpose of this study was to evaluate the CT angiography (CTA) findings of pulmonary arteriovenous malformation (PAVMs) in patients with hereditary hemorrhagic telangiectasia and to correlate these findings with those of graded contrast-enhanced transthoracic echocardiography (CE-TTE). MATERIALS AND METHODS: A retrospective review was conducted of PAVMs visualized at CTA of patients with abnormal CE-T TE findings (3-point scale). Location, distribution, size, number, volume, grade, and relative attenuation (attenuation of PAVM divided by attenuation of aorta) of PAVMs were recorded. PAVMs were graded as follows on conventional and maximum-intensity-projection (MIP) images: 0, nodule, unlikely PAVM; 1, ground-glass opacity (GGO); 2, GGO with increased vascular network; 3, GGO or nodule with single vessel; 4, GGO or nodule with two or more vessels; 5, GGO or nodule with afferent and larger efferent vessels; 6, mature arteriovenous malformation. Correlation between PAVM grade and relative attenuation and between CTA variables and CE-TTE grades was assessed. RESULTS: Forty patients (median age, 14.9 years; range, 0.6-27.9 years) had 117 PAVMs at CTA: 107 peripheral, eight central, and two both peripheral and central. None of the PAVMs was diffuse. Median size and volume were 0.4 cm (range, 0.1-4.4 cm) and 0.031 mL (range, 0.0009-10.019 mL). At CTA, seven PAVMs were grade 1, five grade 2, 28 grade 3, 62 grade 4, two grade 5, and 13 grade 6. MIP images showed 39 of 117 PAVMs were higher grade. Statistically significant cor relation was found between relative attenuation and PAVM grade (p < 0.001, r = 0.58) in 40 patients and between all CTA variables and CE-TTE (p < 0.05, strongest correlation with highest grades [p < 0.0001, r = 0.81]) in 32 patients. CONCLUSION: In children and young adults with hereditary hemorrhagic telangiectasia, grade 4 PAVMs were most common. Higher-grade PAVMs more often have right-to-left shunts.