Pelvic Endometriosis on MRI: What Not to Miss

Genital / Reproductive system female, Pelvis, MR, Education, Education and training Authors: R. F. D. Oliveira, A. C. Figueiredo Silva, A. Martínez Arribas, R. Madaleno, L. Curvo-Semedo DOI: 10.26044/ecr2026/C-19754 Learning objectives To review and illustrate the MRI findings of pelvic endometriosis, emphasizing the spectrum of appearances of ovarian endometriomas and deep infiltrating endometriosis (DIE), and to highlight key imaging signs that support diagnosis and impact on preoperative planning.

Endometriosis affects approximately 10% of women of reproductive age and is strongly associated with chronic pelvic pain and infertility [1,2]. The disease is characterized by endometrial-like tissue located outside of the uterine corpus, which causes cyclical hemorrhage, inflammation, and fibrosis [3]. Diagnosis is often delayed, as definitive confirmation still relies on laparoscopy with histological analysis [1].MRI has emerged as a second-line technique after ultrasound, offering a comprehensive evaluation of endometriomas, superficial peritoneal implants, and deep infiltrating endometriosis [2,4]. Its ability to assess all pelvic compartments... Findings and procedure details On MRI, endometriosis demonstrates a wide range of imaging findings.The disease may involve the ovaries, peritoneum, and deep pelvic structures, with lesions characterized by a combination of hemorrhagic and fibrotic components.Ovarian endometriomas (Fig 1 - 2) are among the most common manifestations and typically appear as uni or multilocular cystic lesions with high signal intensity on T1-weighted and fat-suppressed T1 sequences, due to blood degradation products [3,6]. Persistent hyperintensity after fat suppression helps distinguish endometriomas from fat-containing lesions [3]. On T2-weighted images, they often exhibit...

Pelvic MRI is a highly accurate, non-invasive, and indispensable tool for the diagnosis and preoperative mapping of deep infiltrating endometriosis. It enables detailed evaluation of sites difficult to access with laparoscopy or ultrasound, facilitating precise and conservative surgical strategies. MRI should be considered a complementary examination to ultrasound, particularly in suspected extensive or deep disease, and ideally integrated within a multidisciplinary management approach. Personal information and conflict of interest R. F. D. Oliveira: Nothing to disclose A. C. Figueiredo Silva: Nothing to disclose A. Martínez Arribas: Nothing to disclose R. Madaleno: Nothing to disclose L. Curvo-Semedo: Nothing to disclose

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