Developing an MR Imaging Strategy for Diagnosis of Ovarian Masses RadioGraphics 2006; 26:1431–1448 Presented by Int 蘇春梅 Supervised by Dr.順星橋

Use of MRI for diagnosis of ovarian masses Morphologic characteristics (cystic masses, cystic and solid masses, and solid masses) Signal intensity characteristics on T1-and T2-weighted images High signal on T1: Endometriotic cyst Low signal on T2: Fibrothecomas Adequate use of intravenous contrast material

WHO Histologic Classification of Ovarian Tumors

MR Imaging criteria for malignant ovarian tumors Primary criteria A solid mass or large solid component Wall thickness greater than 3 mm Septal thickness greater than 3mm and/or vegetations or nodularity Necrosis

MR Imaging criteria for malignant ovarian tumors Ancillary criteria Involvement of pelvic organs or the sidewall Peritoneal, mesenteric, or omental disease Ascites Adenopathy

Sensitivity for malignancy: 91%–100% Specificity : 91%-92%

Three groups of ovarian tumors Cystic masses Cystic and solid masses Predominantly solid masses

Cystic Masses Unilocular Cystic Masses ( Functional cysts, paraovarian cysts, hydrosalpinx, serous cystadenomas) Multilocular Cystic Masses ( Endometriotic cysts, mucinous cystadenomas, mucinous cystic tumors)

Unilocular Cystic Masses Well-circumscribed cystic masses Low signal intensity on T1-weighted images High signal intensity on T2-weighted images

Unilocular Functional Cysts Solitary follicle cysts and Corpus luteum cysts Smooth linings that contain serous or bloody fluid Regress within 2 months Complicated by rupture and cause abdominal pain and hemoperitoneum.

Hemorrhagic functional cyst (Axial T1-weighted image) High-signal-intensity rim Solitary cyst ( Right ovary) Hemorrhagic functional cyst in a 33-year-old woman. Axial T1-weighted (a) and T2-weighted (b) images show a solitary cyst (arrows) in the right ovary. The cyst has a high-signal-intensity rim on both images, which is suggestive of a subacute hematoma. M uterine leiomyoma. Uterine leiomyoma

Hemorrhagic functional cyst ( T2-weighted image) High-signal-intensity rim

Functional cyst (Axial T2-weighted image) Unilocular cystic mass (Right ovary) Uterus Left ovary Functional cyst in an 18-year-old woman. U uterus, curved arrow left ovary. (a) Axial T2-weighted image shows a unilocular cystic mass (straight arrows) in the right ovary. (b) On a contrast-enhanced fat-suppressed T1-weighted image, the cyst wall appears smooth without vegetations or nodularity (straight arrows). Transvaginal US was performed 2 weeks after MR imaging, and the mass was definitely diagnosed as a functional cyst because of its regression

Functional cyst (Contrast-enhanced fat-suppressed T1-weighted image) Smooth cyst wall (without vegetations or nodularity) Uterus Left ovary

Unilocular Paraovarian cysts Not ovarian masses Arise from mesothelial, paramesonephric or mesonephric (wolffian) structures Mesosalpinx between the ovary and fallopian tube, and close to the ipsilateral round ligament Contain serous fluid with a thin wall

Paraovarian cyst (Coronal T2-weighted image ) Left ovary Pelvic mass (cystic and unilocular) Paraovarian cyst in a 23-year-old woman. (a) Coronal T2-weighted image (half-Fourier acquisition single-shot turbo spin echo) shows a pelvic mass (arrows) that is cystic and unilocular. Normal bilateral ovaries (arrowheads) are demonstrated separately from the mass. B bladder. (b) On an axial contrast-enhanced fat-suppressed T1-weighted image, the mass (short straight arrows) abuts the right round ligament (long straight arrow). At surgery, a right paraovarian cyst was found. U uterus, curved arrow left ovary Bladder

Paraovarian cyst (Axial contrast-enhanced fat-suppressed T1-weighted image) Right paraovarian cyst Left ovary Uterus Right round ligament

Unilocular Hydrosalpinx Dilated fallopian tubes appear as fluid-filled structures that are sausage-shaped and/or C- or S-shaped Salpingitis and pelvic endometriosis are common

Hydrosalpinx ( Sagittal T2-weighted ) Large unilocular cystic mass (Left) Figure(4).Hydrosalpinx in a 48-year-old woman. Sagittal T2-weighted (a) and contrast-enhanced fat-suppressed T1-weighted (b) images show a large unilocular cystic mass (arrows). The preoperative diagnosis was a serous cystadenoma of the ovary; however, a huge left hydrosalpinx was found at surgery. U uterus.

Hydrosalpinx (contrast-enhanced fat-suppressed T1-weighted )

Unilocular Serous tumors 25% of benign ovarian neoplasms 12-23% ~ Bilateral involvement Serous cystadenomas are unilocular or multilocular cysts filled with clear watery fluid Lining of the cyst is flat or may have small papillary projections MRI: Unilocular cyst with a thin wall

Serous cystadenoma ( Sagittal T2-weighted ) Hyperintense unilocular cyst Figure 5. Serous cystadenoma in a 27-year-old woman. U uterus. (a) Sagittal T2-weighted image shows a hyperintense mass that is cystic and unilocular (arrows). (b) On a contrast-enhanced fat-suppressed T1-weighted image, the cyst wall appears smooth without vegetations, nodularity, or a solid component (arrows).

Serous cystadenoma ( Contrast-enhanced fat-suppressed T1-weighted )

Multilocular Cystic Masses (1) Endometriotic cysts (2) Mucinous cystadenomas (3) Mucinous cystic tumors of borderline malignancy

MRI findings for ovarian endometriotic cysts Both T1- and T2-: High signal (OR) T1 : High and T2 : Low signal (shading) Methemoglobin : T1 shortening(亮) Chronic cyclic hemorrhage and high viscosity : T2 shortening (shading) Multicentric growth cysts and associated with fibrous adhesions Sensitivity: 82-90%; Specificity: 91-98% Methemoglobin causes T1 shortening. Chronic cyclic hemorrhage and high viscosity of the contents in the endometriotic cysts cause T2 shortening and produce shading. The cysts show a tendency for multicentric growth (multiplicity) (Fig 6) and are often associated with fibrous adhesions.

Endometriotic cysts (Axial fat-suppressed T1-weighted ) Left ovary Hyperintense cysts Figure6. Endometriotic cysts (chocolate cysts) in a 30-year-old woman. U uterus, curved arrow left ovary. (a) Axial T1-weighted image shows multiple chocolate cysts (multiplicity) in the right ovary. All three cysts are hyperintense (straight arrows, arrowhead). (b) On an axial T2-weighted image, one of the cysts is hyperintense (arrowhead) and the other two are hypointense (ie, shading) (straight arrows). The largest cyst demonstrates extensive shading.

Endometriotic cysts (Axial T2-weighted ) Left ovary Hypointense cyst

Mucinous cystadenoma 41% of benign ovarian neoplasms 2-5% : Bilateral Large multilocular cysts containing gelatinous material or fluid of various viscosity Various signal intensities on both T1 and T2 (stained glass appearance)

Mucinous cystadenoma ( Sagittal T2-weighted ) Large multilocular cystic mass Figure 8. Mucinous cystadenoma in an 18-year-old woman. U uterus. (a, b) Sagittal T2-weighted (a) and fatsuppressedT1-weighted (b) images show a large multilocular cystic mass (arrows). The loculi show various signal intensities on both images (stained glass appearance). The examination was performed with a body coil because the tumor extended to just below the liver. (c) Contrast-enhanced fat-suppressed T1-weighted image shows no solid component within the tumor (arrows). Note that some loculi show high signal intensity on both the pre- and postcontrast images (arrowheads in b and c); these may mimic an enhancing solid component.

Mucinous cystadenoma ( Fat suppressedT1-weighted ) High signal intensity Figure 8. Mucinous cystadenoma in an 18-year-old woman. U uterus. (a, b) Sagittal T2-weighted (a) and fatsuppressedT1-weighted (b) images show a large multilocular cystic mass (arrows). The loculi show various signal intensities on both images (stained glass appearance). The examination was performed with a body coil because the tumor extended to just below the liver. (c) Contrast-enhanced fat-suppressed T1-weighted image shows no solid component within the tumor (arrows). Note that some loculi show high signal intensity on both the pre- and postcontrast images (arrowheads in b and c); these may mimic an enhancing solid component.

Mucinous cystadenoma ( Contrast-enhanced fat-suppressed T1-weighted ) Figure 8. Mucinous cystadenoma in an 18-year-old woman. U uterus. (a, b) Sagittal T2-weighted (a) and fatsuppressedT1-weighted (b) images show a large multilocular cystic mass (arrows). The loculi show various signal intensities on both images (stained glass appearance). The examination was performed with a body coil because the tumor extended to just below the liver. (c) Contrast-enhanced fat-suppressed T1-weighted image shows no solid component within the tumor (arrows). Note that some loculi show high signal intensity on both the pre- and postcontrast images (arrowheads in b and c); these may mimic an enhancing solid component.

Cystic and Solid Masses Ovarian malignancy Includes primary epithelial carcinomas and metastatic tumors Surface epithelial-stromal tumors :90% Serous, Mucinous, Endometrioid, Clear cell and transitional cell (Brenner) tumors

Cystic and Solid Masses (1) Serous papillary adenocarcinoma (2) Mucinous cystadenocarcinoma (3) Metastatic ovarian carcinoma (4) Mature cystic teratoma

Serous papillary adenocarcinoma Most common and 50% of all ovarian malignancies 90% of patients : elevation of CA-125 Intracystic or exophytic papillae are sometimes present

Serous papillary adenocarcinoma ( Axial T2-weighted image ) Cystic and solid mass Figure 10. Serous papillary carcinoma in a 56-year-old woman. (a) Axial T2-weighted image shows a cystic and solid mass (arrows). (b) Contrast-enhanced fat-suppressed T1-weighted image shows the exophytic papillary projections of the tumor (arrows). This is the typical appearance of a serous papillary adenocarcinoma.

Serous papillary adenocarcinoma ( Contrast-enhanced fat-suppressed T1-weighted ) Exophytic papillary projections of the tumor Figure 10. Serous papillary carcinoma in a 56-year-old woman. (a) Axial T2-weighted image shows a cystic and solid mass (arrows). (b) Contrast-enhanced fat-suppressed T1-weighted image shows the exophytic papillary projections of the tumor (arrows). This is the typical appearance of a serous papillary adenocarcinoma.

Mucinous cystadenocarcinoma 11% of ovarian carcinomas >50% have stage I disease Mimic metastases to the ovary from the colon or appendix

Mucinous cystadenocarcinoma ( Axial T2-weighted ) Cystic and abundantly solid mass Figure 11. Mucinous cystadenocarcinoma in a 72-year-old woman. Axial T2-weighted (a) and contrast-enhanced fat-suppressed T1-weighted (b) images show a cystic and abundantly solid mass (arrows). The postoperative diagnosis was a stage IC mucinous cystadenocarcinoma of the left ovary.

Mucinous cystadenocarcinoma (Contrast-enhanced fat-suppressed T1-weighted ) Figure 11. Mucinous cystadenocarcinoma in a 72-year-old woman. Axial T2-weighted (a) and contrast-enhanced fat-suppressed T1-weighted (b) images show a cystic and abundantly solid mass (arrows). The postoperative diagnosis was a stage IC mucinous cystadenocarcinoma of the left ovary.

Metastatic ovarian carcinoma Extragenital tumors of the intestines, stomach, and breast Spread via blood vessels and lymphatics More common than primary ovarian mucinous carcinomas Metastatic carcinomas: Bilateral Primary mucinous carcinomas:Unilateral

Metastatic ovarian carcinoma ( Sagittal T2-weighted ) Multicystic mass Rectal tumor Figure 12. Metastatic ovarian carcinoma in a 46-year-old woman. Sagittal T2-weighted (a) and contrast-enhanced fat-suppressed T1-weighted (b) images show a multicystic mass (short arrows) with a solid component. The irregular thick septa and solid component enhance on the postcontrast image (arrowheads in b). A rectal tumor is also seen (long arrow). At surgery, a rectal carcinoma and a metastatic tumor of the right ovary were found.

Metastatic ovarian carcinoma ( Contrast-enhanced fat-suppressed T1-weighted ) Irregular thick septa and solid component Figure 12. Metastatic ovarian carcinoma in a 46-year-old woman. Sagittal T2-weighted (a) and contrast-enhanced fat-suppressed T1-weighted (b) images show a multicystic mass (short arrows) with a solid component. The irregular thick septa and solid component enhance on the postcontrast image (arrowheads in b). A rectal tumor is also seen (long arrow). At surgery, a rectal carcinoma and a metastatic tumor of the right ovary were found. Rectal tumor

Mature cystic teratoma 20% of all ovarian neoplasms Mesodermal, endodermal, and ectodermal derivatives are present in the tumor Benign tumor includes ectodermal derivatives (sebaceous contents) Fatty tissue: High-signal-intensity on T1 and T2

Mature cystic teratoma ( Axial T1-weighted ) Fat Tooth Debris Figure 13. Mature cystic teratoma in a 23-year-old woman. Axial T1-weighted (a) and T2-weighted (b) images show a well-defined hyperintense mass (short arrows). A typical fat (Fa)–fluid (Flu) level is seen with floating debris (D). There is chemical shift artifact (arrowheads) at the boundary between the floating debris and the fatty component. The hypointense nodule (long arrow) represents a tooth within the tumor. Fluid

Mature cystic teratoma ( Axial T2-weighted ) Figure 13. Mature cystic teratoma in a 23-year-old woman. Axial T1-weighted (a) and T2-weighted (b) images show a well-defined hyperintense mass (short arrows). A typical fat (Fa)–fluid (Flu) level is seen with floating debris (D). There is chemical shift artifact (arrowheads) at the boundary between the floating debris and the fatty component. The hypointense nodule (long arrow) represents a tooth within the tumor.

Solid Masses Benign, borderline and malignant tumors Fibroma and Fibrothecoma : solid benign tumors

Fibroma ( Sagittal T2-weighted ) Hypointense solid mass Uterus Figure 15. Fibroma in a 52-year-old woman. (a) Sagittal T2-weighted image shows a hypointense solid mass (arrows). U uterus. (b, c) Unenhanced (b) and contrast-enhanced (c) fat-suppressed T1-weighted images show weak enhancement of the mass (arrows) compared with that of the uterine myometrium (U). No vascular signal void is seen between the uterus and the mass.

Fibroma ( Unenhanced fat-suppressed T1) Figure 15. Fibroma in a 52-year-old woman. (a) Sagittal T2-weighted image shows a hypointense solid mass (arrows). U uterus. (b, c) Unenhanced (b) and contrast-enhanced (c) fat-suppressed T1-weighted images show weak enhancement of the mass (arrows) compared with that of the uterine myometrium (U). No vascular signal void is seen between the uterus and the mass.

Fibroma ( Contrast-enhanced fat-suppressed T1) Weak enhancement of the mass Figure 15. Fibroma in a 52-year-old woman. (a) Sagittal T2-weighted image shows a hypointense solid mass (arrows). U uterus. (b, c) Unenhanced (b) and contrast-enhanced (c) fat-suppressed T1-weighted images show weak enhancement of the mass (arrows) compared with that of the uterine myometrium (U). No vascular signal void is seen between the uterus and the mass.

Fibrothecoma Most common solid benign tumors Sex cord-stromal tumors Composed of spindle, oval, or round cells forming various collagen Edema and cyst formation T2 : Mixed low to high signal Estrogenic and uterine enlargement

Fibrothecoma ( Axial T2-weighted ) Heterogeneous solid mass Enlarged Uterus Figure 16. Fibrothecoma in a 72-year-old woman. Axial T2-weighted image shows a heterogeneous solid mass (arrows) with intermediate to high signal intensity. Ascites is seen in the cul-de-sac. The uterus (U) is enlarged, an abnormal finding in a postmenopausal woman. 72 y/o, postmenopausal woman

Brenner tumor ( Axial T1-weighted ) Low-signal solid mass Multicystic mass Figure 18. Brenner tumor in a 79-year-old woman. Axial T1-weighted (a) and T2-weighted (b) images show a low-signal-intensity solid mass (arrows) that is sharply demarcated. In addition, a multicystic mass (arrowheads) is seen beside the solid mass. At surgery, a Brenner tumor (solid mass) and an associated mucinous cystadenoma (multicystic mass) were found.

Brenner tumor ( Axial T2-weighted ) low-signal-intensity solid mass Multicystic mass (mucinous cystadenoma) Figure 18. Brenner tumor in a 79-year-old woman. Axial T1-weighted (a) and T2-weighted (b) images show a low-signal-intensity solid mass (arrows) that is sharply demarcated. In addition, a multicystic mass (arrowheads) is seen beside the solid mass. At surgery, a Brenner tumor (solid mass) and an associated mucinous cystadenoma (multicystic mass) were found.

Granulosa cell tumor ( Axial T1-weighted ) Solid mass Cyst Hemorrhagic cyst (Hyperintense) Figure 19. Granulosa cell tumor in a 55-year-old woman. Axial T1-weighted (a) and T2-weighted (b) images show a mass with a predominantly solid appearance (arrows). Cystic components are seen in the tumor; some of them are hemorrhagic, thus appearing hyperintense on both images (arrowheads).

Granulosa cell tumor ( Axial T2-weighted ) Figure 19. Granulosa cell tumor in a 55-year-old woman. Axial T1-weighted (a) and T2-weighted (b) images show a mass with a predominantly solid appearance (arrows). Cystic components are seen in the tumor; some of them are hemorrhagic, thus appearing hyperintense on both images (arrowheads).

Serous carcinoma ( Axial T2-weighted ) Solid nodular mass Bilateral external iliac lymph nodes Figure 21. Serous carcinoma in a 40-year-old woman. Axial T2-weighted (a) and contrast-enhanced fat-suppressed T1-weighted (b) images show a solid nodular mass (arrows). The tumor has nonspecific high signal intensity on the T2-weighted image and demonstrates enhancement on the contrast-enhanced image. In addition, there is enlargement of bilateral external iliac lymph nodes (arrowheads), which is a strong indicator of malignancy.

Serous carcinoma ( Contrast-enhanced fat-suppressed T1-weighted ) Figure 21. Serous carcinoma in a 40-year-old woman. Axial T2-weighted (a) and contrast-enhanced fat-suppressed T1-weighted (b) images show a solid nodular mass (arrows). The tumor has nonspecific high signal intensity on the T2-weighted image and demonstrates enhancement on the contrast-enhanced image. In addition, there is enlargement of bilateral external iliac lymph nodes (arrowheads), which is a strong indicator of malignancy.

Diagnosis of Ovarian Masses with MRI