Samsung White Paper: Comparison of MV-Flow™ and power Doppler for assessing lesion vascularization in rectal endometriosis

Introduction
 Pelvic endometriosis is a chronic and benign condition thought to affect up to 5-10% of women. It is accepted that this disease has three different forms, namely: ovarian endometriosis, superficial endometriosis and deep endometriosis. Pelvic endometriosis may affect to multiple sites and organs in the pelvis, with the rectum and sigmoid colon being of the most commonly involved.
 The pathophysiology of this entity is not fully understood. However, it should be noted that there is increasing evidence that the development of endometriosis involves endocrine, immunological, pro-inflammatory and pro-angiogenic processes that interact with each other. Particularly, angiogenesis is a key link in the pathogenesis of endometriosis.
 Transvaginal sonography (TVS) is the first-line imaging technique in the diagnosis of pelvic endometriosis and for deep endometriosis8. Color and power Doppler ultrasound may be used for assessing vascularization of endometriotic lesions. In fact, Doppler has shown that vascularization is related to disease activity in ovarian endometriomas. However, traditionally, endometriotic nodules in deep endometriosis have been considered as very poorly vascularized lesions.
 Microvascular flow (MV-Flow™) imaging allows visualization of small vessels with slow blood flow velocity. Compared to conventional Doppler imaging techniques, MV-Flow™ uses a lower pulse repetition frequency and higher frame rate. The high frame rate provides high resolution details showing both macro- and microvascular blood flow and the advanced filtering modes can reduce artifacts from random motion while preserving the detection of directional motion from flowing blood. This adaptive filtering technique result in a greater sensitivity to lower-velocity blood flow evaluation. Hence, The MV-Flow™ imaging has improved its ability to detect small vessels.
 In the present study we aimed to compare the vascularization of rectal endometriotic nodules using MV-Flow™ to conventional power Doppler.