C:/ITOOLS/WMS/CUP-NEW/18443093/WORKINGFOLDER/JAYAPRAKASAN/9781316645178C04.3D 41 [41–68] 5.7.2019 11:03PM Chapter 4 Sonographic Assessment of Uterine Fibroids and Adenomyosis Francisco Sellers López, Belén Moliner Renau and Rafael Bernabeu Pérez Introduction Uterine fibroids (or leiomyomas) are the most common benign gynaecological tumours, formed by smooth mus- cle and connective tissue. Most are asymptomatic, but sometimes may cause pain, pressure symptoms, metror- rhagia, infertility due to implantation failure, miscar- riage, preterm delivery, and puerperal haemorrhage. Fibroids can be single or multiple. Their size and loca- tion vary and they may undergo benign degenerative changes: atrophic and hyaline degeneration, calcifica- tion, infection, and infarction. Malignant degeneration towards leiomyosarcoma is extremely rare, occurring in less than 0.2 per cent of cases [1]. Adenomyosis is defined as the presence of endome- trial tissue with its glands and stroma, implanted in the myometrium. Dysmenorrhoea and abnormal uterine bleeding in nulliparous women are the usual presenting symptoms associated with this condition. Adenomyosis is reportedly linked to infertility; however, the exact mechanism of this negative effect is unknown [2–8]. In addition, an association between this condition and var- ious obstetric diseases (preterm delivery, growth retar- dation, recurrent bleeding, etc.) has also been found [9]. Ultrasound scans – two-dimensional (2D), power Doppler (PD) angiography and three-dimensional (3D) – are often adequate to make a definitive diagnosis and plan subsequent management. These investigations are the preferred diagnostic tools due to lower cost, accessibility, patient tolerability and minimal invasive- ness of the procedure compared to other modalities [10]. The aim of this chapter is to provide an overview of the ultrasound diagnosis of uterine fibroids and adenomyosis and their sonographic appearance in typical and atypical cases, and to provide guidance when pitfalls are encountered. Uterine Fibroids Transvaginal ultrasound with high-frequency endocavi- tary transducers and wide angles of acquisition constitute the best diagnostic tool for describing uterine leiomyomas. On occasion, transabdominal ultrasound may provide better details, particularly in cases of large fibroids. The lower frequency of abdominal ultrasound transducers allows assessment of structures at a greater distance, and therefore, both routes can be combined for detailed analysis (Figure 4.1). Occasionally, application of abdominal pressure with the non-scanning hand may move the fibroid closer to the transvaginal transducer, allowing better visualization of the fibroid and sur- rounding structures. Modern ultrasound equipment is delivered with predefined technical settings for a gynaecological examination recommended by the manufacturer. In general, the preset parameters are very suitable and usually do not need to be modified. In 2D mode these parameters include frequency, power, gain, dynamic range and greyscale; in PD mode they include wall filter and the pulse repeated frequency (PRF); and in 3D/4D mode they include acquisition mode, volume angle, quality and various image display modalities including sectional planes and render modes. Nevertheless, in some cases these settings need to be modified depending on the patient’s characteristics (body mass index, uterine position, uterine size), the particular type of examination and the preferences of the examiner. Attenuation of ultrasound waves through fibroid is common and therefore assessment in ‘penetration mode’ (low frequency and better depth, but at the cost of resolution) may often be needed, especially in cases of an enlarged uterus with multiple fibroids. Myomas appear on the ultrasound as rounded or oval structures, well defined and circumscribed nod- ular masses, usually hypoechogenic and homoge- neous with respect to the surrounding myometrium. Occasionally, these fibroids are minimally echogenic, appearing as small cystic masses in the myometrial layer (Figure 4.2). The echogenicity depends on the amount of fibrous tissue present in the smooth 41