Spontaneous T1-Hyperintensity Within an Ovarian Lesion: Spectrum of Diagnoses  Hélène Peyrot, MD, Pierre-François Montoriol, MD, Michel Canis, MD  Canadian Association of Radiologists Journal  Volume 66, Issue 2, Pages 115-120 (May 2015) DOI: 10.1016/j.carj.2014.07.006 Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

Figure 1 Diagram that shows the reasoning at magnetic resonance imaging and the main etiologies to consider in the presence of spontaneous elevated signal intensity within an ovarian mass on T1-weighted images. Canadian Association of Radiologists Journal 2015 66, 115-120DOI: (10.1016/j.carj.2014.07.006) Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

Figure 2 Mature cystic teratoma (dermoid cyst). Typical dermoid cyst of the right ovary incidentally discovered during a routine ultrasound examination of a 32-year-old woman. (A) Axial T2- and (B) T1-weighted images, displaying a well-delineated tumour (white arrow in A) filled with heterogeneous hyperintense material on both sequences. (C) The drop in signal on fat-saturated T1 sequence proves the fatty nature of the content and allows the diagnosis of a simple mature cystic teratoma. Canadian Association of Radiologists Journal 2015 66, 115-120DOI: (10.1016/j.carj.2014.07.006) Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

Figure 3 Functional cyst. Corpus luteum (white arrow in [A] and in [B]) of the left ovary of a 28-year-old woman in whom magnetic resonance imaging was performed for characterization of a right ovarian cyst, also visible. (A) Axial T2-weighted image, showing a small unilocular cyst with moderate-high signal intensity. (B) Coronal fat-saturated T1-weighted image, exhibiting a typical hyperintense rim related to hemorrhage within the cyst's wall. Canadian Association of Radiologists Journal 2015 66, 115-120DOI: (10.1016/j.carj.2014.07.006) Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

Figure 4 Endometriomas. Multiple endometriomas (white arrows in [A]) of the left ovary of an 18-year-old girl with a history of chronic pelvic pain. (A) Axial T2-weighted image, showing several unilocular cysts within the left ovary, with homogeneous low signal intensity, which realizes the so-called shading aspect of endometriomas. (B) On the corresponding fat-saturated T1-weighted image, the cysts display a bright signal (“light bulb” appearance). Canadian Association of Radiologists Journal 2015 66, 115-120DOI: (10.1016/j.carj.2014.07.006) Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

Figure 5 Ovarian hematoma. Right adnexal torsion with ovarian hematoma in a 49-year-old woman who presented with recurrent acute pelvic pain. (A) A large lesion with heterogeneous low signal intensity (white arrow) that corresponds to an enlarged ovary filled with blood products can be seen on axial T2-weighted image. (B) Axial fat-saturated T1-weighted image, showing a typical hyperintense hemorrhagic rim. Canadian Association of Radiologists Journal 2015 66, 115-120DOI: (10.1016/j.carj.2014.07.006) Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

Figure 6 Mucinous cystadenoma. Large mucinous cystadenoma of the right ovary in a 39-year-old woman. (A) Axial T2-weighted image, showing a voluminous multilocular cystic mass with thin septae. (B) Some of the locules are filled with mucinous material (✴), which is responsible for the slightly elevated signal intensity on T1-weighted sequences (axial fat-saturated T1-weighted image). Canadian Association of Radiologists Journal 2015 66, 115-120DOI: (10.1016/j.carj.2014.07.006) Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

Figure 7 Borderline mucinous cystadenoma. Large borderline mucinous cystadenoma in a 45-year-old woman who presented with a large multilocular cystic mass with some thickened septae (white arrow in [A], sagittal T2 image). Some locules display high signal intensity on T1-weighted sequence ([B], axial fat-saturated T1 image) due to a gelatinous, dehydrated content (✴). Canadian Association of Radiologists Journal 2015 66, 115-120DOI: (10.1016/j.carj.2014.07.006) Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

Figure 8 Tubo-ovarian abscess. Bilateral tubo-ovarian abscess in a 40-year-old woman who presented with abdominopelvic pain, fever, and mucopurulent discharge. Complex ovarian cystic masses can be seen on an axial T2-weighted image (white arrow in [A]). Cystic components display high signal intensity on fat-saturated image (✴) and a surrounding hemorrhagic rim (short white arrow in [B]) also is present. The walls of these lesions enhance strongly after intravenous administration of gadolinium ([C], axial enhanced fat-saturated T1-weighted image) and a left pyosalpinx also is displayed (white arrow in [D], coronal T2 image). Canadian Association of Radiologists Journal 2015 66, 115-120DOI: (10.1016/j.carj.2014.07.006) Copyright © 2015 Canadian Association of Radiologists Terms and Conditions

Figure 9 Struma ovarii. Struma ovarii of the left ovary in a young patient. (A) Axial T2-weighted and (B) fat-saturated T1-weighted images, showing a multilocular pelvic cystic mass. Some locules are filled with colloid material (✴), which exhibits marked low signal intensity on T2-weighted sequences and corresponding elevated signal intensity on T1-weighted sequences. Canadian Association of Radiologists Journal 2015 66, 115-120DOI: (10.1016/j.carj.2014.07.006) Copyright © 2015 Canadian Association of Radiologists Terms and Conditions