The role of MRI in the evaluation of vascular malformations

Abstract

Objective The aim of this study was to evaluate the role of MRI and MR angiography in the assessment of vascular malformations as compared with the usefulness of duplex sonography and digital subtraction arteriography. Participants and methods A total of 40 patients (age range, 1-35 years; 21 male and 19 female) with diagnosed vascular malformations on the basis of color duplex imaging were examined on a 1.5 T whole-body MR scanner. Using parameters based on a fast localizer sequence, we acquired axial or coronal T1-, T2-, short-time inversion recovery (STIR) and contrast-enhanced T1-weighted images. Dynamic postcontrast three-dimensional (3D) gradient-echo MRIs were used for patients with high-flow arteriovenous malformation. MR data sets were evaluated for the detection of the lesion, determination of the malformation extent, involvement of surrounding structures, and vascular details with regard to the nidus, feeding arteries, and draining veins. Results were compared with findings from the digital subtraction angiography (DSA). Results All MRIs revealed 14 low-flow venous vascular malformations, 12 high-flow arteriovenous malformations, and 14 hemangiomas. The STIR sequence was helpful for determining the extent of vascular malformation, whereas dynamic postcontrast 3D MR angiography helped in the classification of the type of the vascular malformation. MR angiography was inferior to DSA in revealing the vascular details and for interventional procedure planning. Conclusion MRI and MR angiography appear to play a significant role in the assessment of vascular malformations. The protocol for imaging such vascular malformations should include dynamic postcontrast 3D gradient-echo MRI with STIR sequences. However, DSA is still required for more vascular detail delineation and definitive treatment decisions.