Morphologic and functional assessment of vascular abnormalities of the pulmonary vasculature by breath-hold MR techniques

Purpose: To evaluate breath-hold MR techniques for morphologic and functional assessment of vascular abnormalities of the pulmonary vasculature. Patients and Methods: 13 patients aged 11 to 60 years with different vascular abnormalities of the pulmonary vasculature (5 patients with 16 arteriovenous malformations, 8 patients with partial anomalous pulmonary venous return) underwent MR imaging at 1.5 T. For morphological assessment, a contrast-enhanced 3D MR angiography (ce-MRA) was performed after a timing run. Segmented cine- and velocity-encoded GRE sequences were used for delineation of associated cardiac septal defects and for determination of systemic left-to-right or intrapulmonary shunt volumes. Selective intra arterial digital subtraction angiography, cardiac catheterization, and the intraoperative situs served as reference standards. Results: Ce-MRA allowed for detection of all vascular abnormalities and for anatomic characterization of 14/16 arteriovenous malformations. Flow measurements in the feeding arteries allowed for determination of intrapulmonary shunt volumes in 4/5 patients. Flow measurements performed in the pulmonary arteries and the ascending aorta enabled determination of systemic left-to-right shunting in patients with anomalous pulmonary venous return. Cine-sequences clearly depicted associated cardiac septal defects. Conclusion: Breath-hold MR techniques allow for morphological and functional characterization of vascular anomalies of the pulmonary vasculature. Therefore, they are the non-invasive method of choice for planning further treatment.