Value of dynamic contrast-enhanced MR imaging in diagnosing and classifying peripheral vascular malformations

OBJECTIVE: Our purpose was to evaluate prospectively whether MR imaging, including dynamic contrast-enhanced MR imaging, could be used to categorize peripheral vascular malformations and especially to identify venous malformations that do not need angiography for treatment. SUBJECTS AND METHODS: In this blinded prospective study, two observers independently correlated MR imaging findings of 27 patients having peripheral vascular malformations with those of diagnostic angiography and additional venography. MR diagnosis of the category, based on a combination of conventional and dynamic contrast-enhanced MR parameters, was compared with the angiographic diagnosis using gamma statistics. Sensitivity and specificity of conventional MR imaging and dynamic contrast-enhanced MR imaging in differentiating venous from nonvenous malformations were determined. RESULTS: Excellent agreement between the two observers in determining MR categories (gamma = 0.99) existed. Agreement between MR categories and angiographic categories was high for both observers (gamma = 0.97 and 0.92). Sensitivity of conventional MR imaging in differentiating venous and nonvenous malformations was 100%, whereas specificity was 24-33%. Specificity increased to 95% by adding dynamic contrast-enhanced MR imaging, but sensitivity decreased to 83%. CONCLUSION: Conventional and dynamic contrast-enhanced MR parameters can be used in combination to categorize vascular malformations. Dynamic contrast-enhanced MR imaging allows diagnosis of venous malformations with high specificity.