Introduction

Uterine myoma is the most common benign tumor pathologically composed of smooth muscle cells and connective tissue. In most cases, this lesion is incidentally detected. Even symptomatic myoma is curable using less invasive treatments including thermal ablation, embolization, and myomectomy. Ultrasonography is a primary examination for detecting or characterizing uterine myoma and CT or MRI is necessary to identify the lesion’s location, number, and size prior to making an appropriate plan. Since uterine myoma may have degeneration and invades or metastasizes as if it were a malignant tumor, various imaging features may lead to a misdiagnosis. Therefore, it is essential to be familiar with imaging features of uterine myoma. This chapter will describe imaging features of ordinary or degenerated myoma, unusual types or growth patterns of myoma, and differential diagnoses. Myoma, also known as leiomyoma or fibroid, is the most common tumor of the uterus, occurring in 20-30% of women of reproductive age. It is often encountered as an incidental finding for other indications or is preoperatively evaluated for symptomatic patients with US, CT, MRI, or [ 18 F]-2-fluoro-2-deoxyglucose (18 F-FDG) positron emission tomography (PET)/CT. Most of all, MR images have been considered the best imaging technique for the detection, localization, and characterization of gynecologic neoplasms with the advantages of superb contrast of soft tissue and multiplanar capability without radiation.