Color coded perfusion analysis and microcirculation imaging with contrast enhanced ultrasound (CEUS) for post-interventional success control following thermal ablative techniques of primary and secondary liver malignancies.

Abstract

Evaluation of the post-interventional success following ablative techniques (radiofrequency and microwave) using a new color coded perfusion quantification software with CEUS in patients with primary and secondary liver malignancies. 75 patients (60 males, 15 females, age 24-84 years, mean 62.7 years) with 128 malignant liver lesions were included in this study. Between 01/2013 and 06/2018, the therapeutic interventional procedure in 88 lesions was MWA, in 40 lesions RFA. All patients underwent CEUS using a convex multifrequency probe (1-6 MHz) following application of 1-2.4 ml sulphur hexaflouride microbubbles, before and within 24 hours following RFA and MWA to detect residual tumor tissue. Postprocessing of the stored DICOM loops from 15 sec up to 1 min using a perfusion quantification software regarding peak enhancement (pE), time to peak (TTP), mean transit time (MTT), rise time (Ri) and Wash-in area under the curve (WiAUC) in the center of the lesion, the border area and periphery was performed. In patients treated with RFA, pE differences between center of the lesion vs. surrounding liver were found to be statistically extremely significant (p < 0.001), differences between center of the lesion and margin were also statistically significant (p < 0.01). mTT, TTP, WiAuC and Ri showed no significant difference between center, margin or surrounding liver.In patients treated with MWA, statistically significant differences (p < 0.05) were found for pE, Ri and mTT regarding the differences between center of lesion and surrounding tissue. WiAuC and TTP showed no significant differences between center, margin or surrounding liver. CEUS with perfusion imaging is a valuable supporting tool for post-interventional success control following RFA and MWA of primary and secondary liver maligancies. Focus should be placed upon pE following MWA and pE, Ri and mTT following RFA.