Comprehensive time-resolved MRI of peripheral vascular malformations.

OBJECTIVE: The purpose of this study was to evaluate the usefulness of MRI and MR angiography for the assessment of peripheral vascular malformations compared with the usefulness of conventional duplex sonography, venography, and arteriography. SUBJECTS AND METHODS. Nineteen patients (age range, 8-64 years; 11 males and eight females) with clinically diagnosed or suspected angiodyplastic abnormalities of the extremities were examined on a 1.5-T whole-body MR scanner. Using parameters based on a fast localizer sequence, we acquired transverse or coronal T1-, T2-, short tau inversion recovery (STIR), and contrast-enhanced T1-weighted images. Dynamic contrast-enhanced three-dimensional (3D) gradient-echo MRIs were acquired to determine the extent and type of the arteriovenous malformation for each patient. MR data sets were evaluated for lesion depiction, determination of the extent of the malformation, involvement of neighboring structures, vascular detail, and treatment planning. Results were compared with findings from duplex sonography, venography, and intraarterial digital subtraction angiography.

RESULTS: All MRIs were of diagnostic quality and revealed 12 venous vascular malformations, four arteriovenous malformations, and three hemangiomas. The STIR sequence was helpful for determining the extent of the vascular malformation, which was often underestimated using contrast-enhanced 3D MR angiography alone, whereas dynamic contrast-enhanced 3D MR angiography was required for classifying the type of the lesion. MR angiography was inferior to conventional angiography for revealing vascular detail and for planning intervention.

CONCLUSION: MRI and MR angiography appear to be valuable for the assessment of vascular malformations of the extremities. The protocol for imaging such malformations should combine dynamic contrast-enhanced 3D gradient-echo MRI with STIR sequences. However, digital subtraction angiography and venography are still required for definitive treatment decisions.