Contrast-enhanced Ultrasonography Assessment of Therapeutic Efficacy for Ultrasound-guided High-intensity Focused Ultrasound Ablation of Uterine Fibroids: Comparison with Contrast-enhanced Magnetic Resonance

BackgroundAn accurate and convenient technique is needed for assessment of therapeutic efficacy for ultrasound (US)-guided high-intensity focused ultrasound (HIFU) ablation of uterine fibroids. The accuracy of contrast-enhanced ultrasonography (CEUS) was tested in this study using contrast-enhanced magnetic resonance (CEMR) as a standard of reference.Materials and methodsA total of 67 women with 71 uterine fibroids (mean ± standard deviation, 7.6 ± 3.5 cm; range, 4.3–19.0 cm) underwent US-guided HIFU ablation. The immediate therapeutic efficacy was observed by CEUS performed immediately after treatment. The nonperfused ablation ratio was measured on CEUS and CEMR. During follow-up, CEUS was compared with CEMR regarding the detection rate of enlargement of viable fibroids.ResultsResidual viable portions were detected in four patients by CEUS performed just after US-guided HIFU ablation and which received immediate reablation. There was good agreement between CEMR and CEUS for the measurement of nonperfused ablation ratio (Intraclass correlation coefficient (ICC) = 0.912, p < 0.01). During follow-up, CEUS detected all enlargement of viable fibroid shown on CEMR. The gradual shrinkage of the ablated fibroids was also clearly depicted by CEUS.ConclusionCEUS may be used as a convenient alternative to CEMR in the assessment of therapeutic efficacy for US-guided HIFU ablation of uterine fibroids.