Fibroid vascularisation assessed with 3D Power Doppler as predictor for fibroid related symptoms and quality of life; a pilot study

Microvascular flow imaging of fibroids: A prospective pilot study

INTRODUCTION

Imaging fibroid vascularity may predict fibroid growth and aid to determine most appropriate therapy. Microvascular (MV) flow imaging is relatively new and is able to detect slow flow in small vessels. Data on feasibility, reproducibility, and reliability of MV-flow imaging in fibroids is lacking. The purpose of our study was to determine the reproducibility of MV-flow imaging and to explore this technique for clinical practice for assessing blood flow in fibroids.

MATERIAL AND METHODS

Thirty patients with one or multiple fibroids (diameter 1.5-12.0 cm) were prospectively included. Transvaginal ultrasound scanning was performed in B-mode, 2D MV-Flow™, 2D and 3D power Doppler mode (HERA W10, Samsung) by two experienced gynecologists at a tertiary care clinic from February to December 2021. The primary outcome was intra- and interobserver agreement of the vascular index (VI) and color score (CS). The following parameters: '2D MV-flow VI', '3DPD VI', '2D MV-flow CS' and '2DPD CS' were measured offline in the center, pseudocapsule, and entire fibroid. Secondary offline outcomes for exploring 2D MV-flow for clinical practice, included (1) ability to discern vascular structures, (2) assessing the degree of vascularity via CS and calculating a VI, and (3) determining penetration depth of the ultrasound signal in both power Doppler and MV-flow imaging.

RESULTS

All scans of the 30 included patients were of sufficient quality to analyze. Inter- and intra-observer correlations of all studied parameters were good to excellent, both for 2D MV-flow and 2D power Doppler (intercorrelation coefficient 0.992-0.996). Using 2D MV-flow different vascular structures were visible in detail, in contrary to using 2D and 3D power Doppler. In significantly more fibroids central flow could be visualized using 2D MV-flow (63%) than with 2D power Doppler (13%, p = 0.001). Finally, penetration of the ultrasound signal was deeper using 2D MV-flow (3.92 cm) than with 2D power Doppler (2.95 cm, p = 0.001).

CONCLUSIONS

Using 2D MV-flow imaging for determining vascularity is highly reproducible. It has potential added value for clinical practice as it depicts detailed vascular structures and the degree of vascularity, especially in the center of the fibroid.

Clinical signs and diagnosis of fibroids from adolescence to menopause

The aim of this review was to provide an updated assessment of the present diagnostic tools and clinical symptoms and signs to evaluate uterine fibroids (UFs) on the basis of current guidelines, recent scientific evidence, and a PubMed and Google Scholar search for peer-reviewed original and review articles related to clinical signs and diagnosis of UFs. Approximately 50%-75% of UFs are considered nonclinically relevant. When present, the most common symptoms are abnormal uterine bleeding, pelvic pain and/or bulk symptoms, and reproductive failure. Transvaginal ultrasound is recommended as the initial diagnostic modality because of its accessibility and high sensitivity, although magnetic resonance imaging appears to be the most accurate diagnostic tool to date in certain cases. Other emerging techniques, such as saline infusion sonohysterography, elastography, and contrast-enhanced ultrasonography, may contribute to improving diagnostic accuracy in selected cases. Moreover, artificial intelligence has begun to demonstrate its ability as a complementary tool to improve the efficiency of UF diagnosis. Therefore, it is critical to standardize descriptions of transvaginal ultrasound images according to updated classifications and to individualize the use of the different complementary diagnostic tools available to achieve precise uterine mapping that can lead to targeted therapeutic approaches according to the clinical context of each patient.

Visualisation of microvascular flow in benign uterine disorders: a pilot study of a new diagnostic technique

BACKGROUND

Uterine disorders have clear overlapping symptoms and ultrasound discrimination is not always easy. Accurately measuring vascularity is of diagnostic and prognostic value. Power Doppler is limited to imaging only the larger vessels. Assessment of the microvasculature requires advanced machine settings.

OBJECTIVES

In this pilot study, we aimed to test the feasibility of microvascular flow imaging of benign uterine disorders.

MATERIAL AND METHODS

Two experienced gynaecologists (JH, RL) randomly applied power Doppler and MV-flowTM mode during a single day, in ten patients each visiting the outpatient clinic. Images of eight patients were labelled with a diagnosis by the attending physicians and collected as coded data.

MAIN OUTCOME MEASURES

Microvascular flow images of normal uterine architecture including the fallopian tube, and of benign disorders such as fibroids, adenomyosis, endometriosis and uterine niches were collected. For both Doppler techniques, qualitative descriptive evaluation of the vascular architecture and a quantitative vascular index of fibroids were provided. Finally, we evaluated the effect of the cardiac cycle.

RESULTS

All microvascular flow images showed more distinctive vascular structures than visible on power Doppler. Calculating a vascular index for fibroids on 2D MV-flowTM images was easily performed on-site. During the cardiac cycle a higher vascular index (VI 75.2) is obtained in systole as compared with diastole (VI 44.0).

CONCLUSION

Microvascular flow imaging allowed detailed visualisation of the uterine vascular architecture and is easy to use.

WHAT IS NEW?

Microvascular flow imaging may be of added value for diagnosing uterine disorders, as well as for pre- and post-operative assessment of suited surgical techniques. Yet, validation with histology and clinical outcomes is required.

How to use power Doppler ultrasound in transvaginal assessment of uterine fibroids

Measuring vascularization in uterine fibroids is important for their diagnosis, treatment and prognosis. Vascularization can be measured by power Doppler ultrasound. The power Doppler signal depends on fibroid characteristics and on a variety of ultrasound-machine settings. Literature describing which machine settings influence the power Doppler signal is limited. Each manufacturer names settings and presets at their own discretion, with little information available publicly. Consistency of machine settings is important for correct interpretation of images in daily practice and is essential in yielding reproducible data for research. The aims of this paper, drawing from both a literature search and semistructured interviews with ultrasound-machine engineers and clinical experts in gynecological ultrasound, were: (1) to provide comprehensive background information on ultrasound physics and fibroid characteristics; (2) to present an overview of machine settings relevant to both two- and three-dimensional power Doppler, including power Doppler frequency, pulse repetition frequency, gain, wall-motion filter, acoustic power, persistence and signal rise; and (3) to provide a step-by-step tutorial on the optimal settings for vascular evaluation of uterine fibroids using power Doppler. The step-by-step tutorial comprises six steps to optimize the power Doppler signal, create a preset and acquire a reliable three-dimensional volume. This step-by-step tutorial should help research groups and clinicians to use power Doppler correctly and reproducibly in the evaluation of uterine fibroids. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.