Contrast-enhanced ultrasound (CEUS) assessment of superselective uterine fibroid embolization (SUFE): Preliminary experience()

Contrast-Enhanced Ultrasound and High Sensitive Doppler for Monitoring Outcomes of Uterine Artery Embolization

RATIONALE AND OBJECTIVES

To monitor fibroid microvascularity using contrast-enhanced ultrasound (CEUS) and a new high-sensitive Doppler mode (SMI) for assessment of uterine artery embolization (UAE) outcomes.

MATERIALS AND METHODS

Forty women with symptomatic uterine fibroids scheduled for UAE were enrolled in this Institutional Review Board-approved study. Subjects underwent three examinations (day 0, 15, and 90 post-UAE) with Color Doppler (CDI), power Doppler (PDI), color and monochrome SMI (cSMI and mSMI), and CEUS imaging of the fibroids. Clips were assessed by two radiologists classifying fibroids based on their vascularity. Fibroid fractional vascularity (FV; % of enhanced pixels within the fibroid) and flow intensity (as mean brightness level of the enhanced pixels) were quantified. Results were analyzed using repeated measures ANOVA and nonparametric Wilcoxon sign rank tests. Inter-reader agreement was assessed with κ-values.

RESULTS

There was overall agreement between readers for all imaging modalities and examination times (P = .25; κ = 0.70). The FV analysis showed statistically significant differences between CEUS and the Doppler imaging modes (CDI, PDI, cSMI, and mSMI) for the three examination times were compared (P < .0001). The comparison using CDI, PDI, and cSMI showed no statistically significant difference (P = .53). The flow intensity analysis comparison between the Doppler imaging modes (CDI, PDI, cSMI and mSMI) and examination times showed statistically significant differences between all the Doppler imaging modalities (P = .02), except for the 90days post-UAE (P = .34). When the comparison was made for CDI, PDI, and cSMI there was no statistically significant differences (P < .47).

CONCLUSION

CEUS and SMI can accurately evaluate fibroid microvascularity, and therefore, can be a noninvasive and accurate method for monitoring outcomes following UAE treatment.

Contrast-Enhanced Ultrasound Imaging of Uterine Disorders: A Systematic Review

Uterine disorders are often presented with overlapping symptoms. The microvasculature holds specific information important for diagnosing uterine disorders. Conventional sonography is an established diagnostic technique in gynecology, but is limited by its inability to image the microvasculature. Contrast-enhanced ultrasound (CEUS), is capable of imaging the microvasculature by means of intravascular contrast agents; that is, gas-filled microbubbles. We provide a literature overview on the use of CEUS in diagnosing myometrial and endometrial disorders, that is, fibroids, adenomyosis, leiomyosarcomas and endometrial carcinomas, as well as for monitoring and enhancing the effectiveness of minimally invasive therapies. A systematic literature search with quality assessment was performed until December 2020. In total 34 studies were included, published between 2007 and 2020.The results entail a description of contrast-enhancement patterns obtained from healthy tissue and from malignant and benign tissue; providing a first base for potential diagnostic differentiation in gynecology. In addition it is also possible to determine the degree of myometrial invasion in case of endometrial carcinoma using CEUS. The effectiveness of minimally invasive therapies for uterine disorders can safely and accurately be assessed with CEUS. In conclusion, the abovementioned applications of CEUS are promising and it is worth further exploring its full potential for gynecology by designing innovative and methodologically high-quality clinical studies.

Comparison of Contrast-Enhanced Ultrasound Versus Magnetic Resonance Imaging in the Detection and Characterization of Uterine Leiomyomas

OBJECTIVES

Uterine fibroids are common findings in women with pelvic pain and abnormal uterine bleeding. The reference standard test in the pretreatment evaluation of fibroids is contrast-enhanced magnetic resonance (MR) imaging. This study compared the number, size, location, and enhancement of uterine fibroids identified by contrast-enhanced ultrasound (CEUS) and MR. The aim of this study was to demonstrate that CEUS performs similarly to MR and could be used as an alternative imaging modality.

METHODS

In this prospective observational study, 26 women underwent transabdominal CEUS and MR examinations. Blinded to the original clinical MR interpretations, 2 readers reviewed the MR and CEUS studies for each patient. The number, size, location, and enhancement of each fibroid per patient were reported by MR and CEUS. A Pearson correlation coefficient was calculated for the number of fibroids identified by each modality.

RESULTS

In total, 126 fibroids were imaged: 115 (91.3%) were observed on both examinations; 9 (7.1%) were observed by MR only; and 2 (1.6%) were observed by CEUS only. A high correlation was found between the modalities for the number of fibroids identified per patient (r = 0.97; P < .001). There was also no significant difference between the modalities for each patient in the fibroid number, size, location, or enhancement.

CONCLUSIONS

These findings suggest that transabdominal CEUS may represent an alternative to MR in pretreatment evaluation of uterine fibroids and could serve as a test of choice in patients with a contraindication to MR.

Contrast-Enhanced Ultrasound for Monitoring Non-surgical Treatments of Uterine Fibroids: A Systematic Review

Non-surgical treatment options for uterine fibroids are uterine artery embolization (UAE), high-intensity focused ultrasound ablation (HIFUA), and percutaneous microwave ablation (PMWA). Magnetic resonance imaging (MRI) is the reference standard imaging method before and after these procedures. Contrast-enhanced ultrasound (CEUS) has been studied as an alternative to MRI for evaluating the fibroids' characteristics and responses to non-surgical treatments. PubMed, Ovid MEDLINE and Scopus databases were searched for literature published from January 2000 through June 7, 2020, that investigated the application of CEUS as an adjunct to monitor UAE, HIFUA or PMWA in human uterine fibroid treatments. Two independent reviewers analyzed 128 publications, out of which 17 were included. Based on this systematic review, CEUS provides detailed data about fibroid volume and vascularization prior, during and post UAE, and it helps determine the endpoint of the procedure. HIFUA with intra-procedural CEUS has faster volume shrinkage over a shorter time period with less needed energy and provides early detection of residual tissue after HIFUA. CEUS and contrast-enhanced MRI have sufficient agreement to be used interchangeably in the clinic to evaluate the therapeutic effect of PMWA and HIFUA on fibroids.

Intraoperative microvascular assessment with contrast-enhanced ultrasound (CEUS) during uterine artery embolisation (UAE): a case report and literature review

The clinical success of uterine artery embolization is determined by its endpoint. An aggressive UAE could lead to endometritis and increases the risk of unintended embolization of other organs. Conversely, an incomplete procedure may result in a poor clinical outcome due to regrowth of the fibroids. We present a case with innovative use of intraoperative contrast-enhanced ultrasonography (CEUS) for the assessment of vascularity of the targeted fibroid to determine the endpoint of embolization perioperatively. We aim to report a case of the use of intraoperative CEUS during UAE to highlight the potential pitfall of its use and provide a review of its application in the literature. Our case affirms the reported usefulness and the practical feasibility to assess the vascularity of fibroids during UAE and highlights that caution should be made by operators in cases of multiple fibroids.

Use of Contrast-Enhanced Ultrasound in the Assessment of Uterine Fibroids: A Feasibility Study

Contrast-enhanced ultrasound (CEUS) is an innovative ultrasound technique capable of visualizing both the macro- and microvasculature of tissues. In this prospective pilot study, we evaluated the feasibility of using CEUS to visualize the microvasculature of uterine fibroids and compared CEUS with conventional ultrasound. Four women with fibroids underwent gray-scale ultrasound, sonoelastography and power/color Doppler scans followed by CEUS examination. Analysis of CEUS images revealed initial perfusion of the peripheral rim, that is, a pseudo-capsule, followed by enhancement of the entire lesion through vessels traveling from the exterior to the interior of the fibroid. The pseudo-capsules exhibited slight hyper-enhancement, making a clear delineation of the fibroids possible. The centers of three fibroids exhibited areas lacking vascularization, information not obtainable with the other imaging techniques. CEUS is a feasible technique for imaging and quantifying the microvasculature of fibroids. In comparison with conventional ultrasound imaging modalities, CEUS can provide additional diagnostic information based on the microvasculature.