Contrast-enhanced ultrasound with perfusion analysis in patients with venous malformations before and after percutaneous treatment with ethanol-gel.

INTRODUCTION: Percutaneous sclerotherapy is a well-established treatment option for venous malformations (VM). A recently established sclerosing agent is ethanol-gel. Aim of this study was to identify, if contrast-enhanced ultrasound (CEUS) with an integrated perfusion analysis allows for differentiation between untreated VM, healthy tissue, and with gelified ethanol treated malformation tissue. MATERIAL AND METHODS: In this institutional review board approved prospective study symptomatic VM patients underwent CEUS at exactly the same position before and after sclerotherapy with ethanol-gel. Two experienced sonographers performed all examinations after the bolus injection of microbubbles using a multi-frequency probe with 6 -9 MHz of a high-end ultrasound machine. An integrated perfusion analysis was applied in the center of the VM and in healthy, surrounding tissue. For both regions peak enhancement (peak), time to peak (TTP), area under the curve (AUC), and mean transit time (MTT) were evaluated. Wilcoxon signed rank test was executed; p-values <0.05 were regarded statistically significant. RESULTS: In 23 patients including children (mean age 25.3 years, 19 females) before treatment all identified parameters were significantly higher in the VM center compared to healthy tissue (peak: p < 0.01; TTP: p < 0.01; AUC: p < 0.01; MTT: p < 0.01). Comparing the VM center before and after treatment, TTP (p < 0.02) and MTT (p < 0.01) reduced significantly after sclerotherapy. In surrounding tissue only peak changed after treatment in comparison to pre-treatment results (p = 0.04). Comparing data in the VM center with surrounding tissue after sclerotherapy, results still differed significantly for peak (p < 0.01), TTP (p < 0.01), and AUC (p < 0.01), but assimilated for MTT (p = 0.07). CONCLUSION: All with CEUS identified parameters seem to be excellent tools for differentiating between VM and healthy tissue. TTP and MTT could distinguish between with ethanol-gel sclerotized VM portions and untreated malformation parts and thereby might assist the monitoring of sclerotherapy with ethanol-gel.

Value of different ultrasound elastography techniques in patients with venous malformations prior to and after sclerotherapy.

AIM: Comparison of different ultrasound elastography techniques for detection of changes after sclerotherapy within venous malformations. MATERIAL AND METHODS: In patients with venous malformations sonography was executed at exactly the same position prior to and after ethanol-gel sclerotherapy. Both examinations included B-Mode, vascular sonography with Color-Coded Duplex Sonography, and additional sonography with different elastography techniques (strain, qualitative and quantitative Acoustic Radiation Force Impulse (ARFI) elastography) with a linear transducer (6-9 MHz). Qualitative elastograms were read in consensus and scored. Differences of elasticity scores were statistically analyzed, p-values <0.05 were regarded significant. RESULTS: Elasticity scores of strain and qualitative ARFI elastography in 25 patients (21 females, averagely 24.4 years old) were comparable before treatment (p = 0.69). After therapy qualitative ARFI scores changed significantly compared to pre-treatment scores (p = 0.0017), whereas strain elastography scores revealed no significant changes (p = 0.13). Quantitative ARFI values obtained after sclerotherapy within the venous malformations were significantly higher compared to pre-treatment values (p = 0.049), and significantly higher to values obtained in surrounding tissue (p = 0.030). Comparison of pre- and post-treatment ARFI values of the surrounding tissue was not significant (p = 0.67). CONCLUSION: Elasticity scores of qualitative ARFI elastography reliably detect ethanol-gel induced changes in venous malformations. Quantitative ARFI may be a tool for therapy planning, and for monitoring sclerotherapy outcome as well as the effect of sclerosing agents on malformation and surrounding tissue in patients with venous malformations.

Color-coded perfusion analysis of CEUS for pre-interventional diagnosis of microvascularisation in cases of vascular malformations.

AIM: Aim of our pilot study was the application of a contrast-enhanced color-coded ultrasound perfusion analysis in patients with vascular malformations to quantify microcirculatory alterations. MATERIAL AND METHODS: 28 patients (16 female, 12 male, mean age 24.9 years) with high flow (n = 6) or slow-flow (n = 22) malformations were analyzed before intervention. An experienced examiner performed a color-coded Doppler sonography (CCDS) and a Power Doppler as well as a contrast-enhanced ultrasound after intravenous bolus injection of 1 - 2.4 ml of a second-generation ultrasound contrast medium (SonoVue®, Bracco, Milan). The contrast-enhanced examination was documented as a cine sequence over 60 s. The quantitative analysis based on color-coded contrast-enhanced ultrasound (CEUS) images included percentage peak enhancement (%peak), time to peak (TTP), area under the curve (AUC), and mean transit time (MTT). RESULTS: No side effects occurred after intravenous contrast injection. The mean %peak in arteriovenous malformations was almost twice as high as in slow-flow-malformations. The area under the curve was 4 times higher in arteriovenous malformations compared to the mean value of other malformations. The mean transit time was 1.4 times higher in high-flow-malformations compared to slow-flow-malformations. There was no difference regarding the time to peak between the different malformation types. The comparison between all vascular malformation and surrounding tissue showed statistically significant differences for all analyzed data (%peak, TTP, AUC, MTT; p < 0.01). High-flow and slow-flow vascular malformations had statistically significant differences in %peak (p < 0.01), AUC analysis (p < 0.01), and MTT (p < 0.05). CONCLUSION: Color-coded perfusion analysis of CEUS seems to be a promising technique for the dynamic assessment of microvasculature in vascular malformations.