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.