Low-flow vascular malformations: MR-guided percutaneous sclerotherapy in qualitative and quantitative assessment of therapy and outcome

PURPOSE: To prospectively assess the therapeutic procedure and outcome of magnetic resonance (MR)-guided percutaneous sclerotherapy in patients with low-flow vascular malformations. MATERIALS AND METHODS: Seventy-six percutaneous sclerotherapy treatments were performed by one radiologist with real-time MR guidance in 15 patients (six female patients; mean age, 54.4 years ± 11.1; nine male patients; mean age, 32.9 years ± 14.1) with vascular malformations in the head and neck (n = 64), spine (n = 5), and extremities (n = 7). Qualitative assessment was used to analyze (a) individual success of therapy, (b) occurrence of complications, (c) time required for minimally invasive MR-guided sclerotherapy in regression analysis, (d) ability of MR imaging to depict postinterventional perfusion changes within the vascular malformation with calculation of changes in contrast-to-noise ratios, and (e) detection of volume changes at follow-up examinations with volumetric analysis. RESULTS: Percutaneous sclerotherapy was performed successfully and without complications by filling targeted vascular malformations with sclerosing agent. Induced vascular sclerosis was used to successfully treat individual predominant symptoms, such as hemorrhage, pain, cosmetic disfigurement, and functional impairment. Quantitative analysis focusing on the actual interventional length of time presented an acceleration over the 5-year time period, matching a cubic function in regression curve fit and taking 31 minutes 50 seconds ± 14 minutes. Induced vascular thrombosis was identified in all treated portions on postinterventional images by the statistically significant changes in contrast-to-noise ratio (P < .05) compared with preinterventional imaging. On follow-up images (ie, those obtained after 12 weeks ± 6), shrinkage was observed in targeted portions (67.2% ± 18.9). CONCLUSION: MR imaging allows safe guidance and monitoring of minimally invasive sclerotherapy and permits verification of therapeutic success postinterventionally and during follow-up examinations.