The superior soft tissue contrast of MRI aids characterisation of adnexal masses. T2-W contrast is the mainstay of diagnosis. Enhancement of T1-W images with gadolinium chelate is helpful in refining diagnosis. Examinations are optimized by scanning after the patient has emptied her bladder and intramuscular antiperistaltic agents have been administered. Classification into benign and malignant pathology is crucial for deciding on type of surgical management. In addition, recognition of disseminated malignant disease determines whether or not neoadjuvant chemotherapy is warranted prior to surgical debulking.
Target Audience: Radiologists in general pelvic imaging and specialist gynecological imaging
Learning Outcome:
· understand the importance of adnexal mass classification in relation to clinical management
· learn optimal techniques to image adnexal masses·
learn how to characterize and correctly classify adnexal masses
Purpose: To describe the role of imaging in relation to the management of adnexal massesBackground: The adnexa refer to the uterine appendages and include fallopian tubes, ovaries, broad ligaments and their vascular pedicles. Adnexal pathologies are either inflammatory or tumors both benign and malignant. The former predominate in younger patients with malignant tumors commoner in an older population. Pain is a common feature of benign pathologies such as ovarian torsion or abscess; ovarian cancer conversely is painless and presents late with disseminated disease and ascites in addition to the ovarian mass.
Management: The management of adnexal masses is predominantly surgical. Imaging helps to decide if surgery is necessary, it’s emergency or elective nature, whether laparoscopic or open procedure is justified and whether local or specialist cancer expertise is required. In disseminated malignancy arising from an adnexal mass, primary surgery may be delayed to first decrease tumor burden with neoadjuvant chemotherapy before surgical debulking. American College of Radiologists guidelines address management of incidental adnexal masses. (Patel, 2013).
Imaging technique: MR has a 91-93% overall accuracy for differentiating benign from malignant lesions (Sohaib, 2003, Zhang, 2014). Current European Society of UroRadiology guidelines recommend that sonographically indeterminate masses be imaged with MRI (Forstner, 2016). The mainstay of imaging adnexal masses is T2-W contrast, but use of gadolinium contrast enhancement may be useful to improve specificity (Hricak, 2000) and semi-quantitative and quantitative methods of analysis have been advocated. In the former, wash-in-rate and time-to-peak have resulted in a sensitivity of 89%, specificity of 93% in a linear discriminant analysis model (Kozerooni, 2017). Quantitative DCE parameters (Thomassin-Nagarra, 2012) are also feasible, and psoas muscle and myometrium are suitable internal references in the DCE assessment (Tang, 2017). Transverse plane images are complemented by coronal, sagittal or oblique views through the mass as required. A multichannel pelvic array coil optimizes signal to noise ratio while intramuscular antiperistaltic agents (glucagon or hyoscine butyl bromide) freeze peristalsis and minimize bowel-induced motion artefact. An empty bladder at the outset of the scan also reduces motion propagation across the image from fluid in the bladder. Fat suppression techniques are useful in characterizing fat within mature teratomas, and T1-W images should be used where endometriosis is suspected to identify hemorrhagic elements. In addition to perfusion, diffusion-weighted imaging is increasingly advocated (Thomassin-Nagarra, 2011) and models combining both diffusion and perfusion information have been proposed (Thomassin-Nagarra, 2015).
Characterization: Adnexal masses may be recognized as uni- or bi-lateral, cystic, solid or mixed, as having septations, papillae, polypoid components or containing fat or hemorrhage. Hemorrhage is a predominant feature of endometriomas, ovarian fibromas and cystadenofiromas have a homogenous mass of short T2 dense fibrous tissue, while fibrothecomas exhibit myxoid degenerative change with less dense stroma (Saini, 2005, Mohaghegh, 2012). Malignant ovarian lesions are complex, with papillary projections within cystic components. Low grade disease is often heavily calcified. Endometroid and clear cell ovarian cancers are distinct histological types but cannot be distinguished from each other or from high grade serous cancer on imaging. Mucinous ovarian cancer is rare and often predominantly cystic with minimal solid components. Borderline ovarian cancer is a distinct entity that needs particular imaging consideration in staging and follow-up as different management pathways apply. Scoring systems based on MR features have been constructed (Thomassin-Naggara, 2013) and successfully applied to distinguish benign from borderline and malignant ovarian masses (Ruiz, 2016). The high accuracy of MRI means that nearly 60% of patients can be managed expectantly based on reassuring results of the MRI (Haggerty, 2014).
Staging ovarian cancer: Assessment of the extent of disease within the pelvis and abdomen is increasingly done with MRI (Kyriazi, 2010). Diffusion-weighted MRI is a particular advantage, as the high contrast between tumor and normal tissue on high b-value (b>1000 s/mm2) enables delineation of the extent of peritoneal disease. Moreover, it is a quantitative technique that can be used to assess response to neoadjuvant chemotherapy (Kyriazi, 2011). Standardization of the technique has allowed this quantitative approach to be employed as a biomarker in multicenter clinical trials.
Conclusion: MRI is the ideal modality for characterising adnexal masses. Its key utility is in determining the appropriate surgical management strategy and in the case of frankly malignant disease, determining extent of disease and need for neoadjuvant chemotherapy prior to surgery.
Patel MD, Ascher SM, Paspulati RM, Shanbhogue AK, Siegelman ES, Stein MW, Berland LL. Managing incidental findings on abdominal and pelvic CT and MRI, part 1: white paper of the ACR Incidental Findings Committee II on adnexal findings. J Am Coll Radiol. 2013; 10: 675-81.
Sohaib SAA, Sahdev A, Van Trappen P, Jacobs IJ, Reznek RH. Characterization of adnexal lesions on MR imaging. AJR 2003; 180: 1297-1304.
Zhang H, Zhang GF, He ZY, Li ZY, Zhang GX. Prospective evaluation of 3T MRI findings for primary adnexal lesions and comparison with the final histological diagnosis. Arch Gynecol Obstet. 2014; 289:357-64.
Forstner R, Thomassin-Naggara I, Cunha TM, Kinkel K, Masselli G, Kubik-Huch R, Spencer JA, Rockall A. ESUR recommendations for MR imaging of the sonographically indeterminate adnexal mass: an update. Eur Radiol. 2016 Oct 21. [Epub ahead of print]
Hricak H, Chen M, Coakley FV, et al. Complex adnexal masses: detection and characterization with MR imaging—multivariate analysis. Radiology 2000; 214:39-46
Kazerooni AF, Malek M, Haghighatkhah H, Parviz S, Nabil M, Torbati L, Assili S, Saligheh Rad H, Gity M. Semiquantitative dynamic contrast-enhanced MRI for accurate classification of complex adnexal masses. J Magn Reson Imaging. 2017;45:418-427.
Thomassin-Naggara I, Balvay D, Aubert E, Daraï E, Rouzier R, Cuenod CA, Bazot M. Quantitative dynamic contrast-enhanced MR imaging analysis of complex adnexal masses: a preliminary study. Eur Radiol. 2012; 22:738-45.
Thomassin-Naggara I, Toussaint I, Perrot N, Rouzier R, Cuenod CA, Bazot M, Daraï E. Characterization of complex adnexal masses: value of adding perfusion- and diffusion-weighted MR imaging to conventional MR imaging. Radiology. 2011; 258:793-803.
Tang YZ, Benardin L, Booth TC, Miquel ME, Dilks P, Sahdev A, Rockall AG. Use of an internal reference in semi-quantitative dynamic contrast-enhanced MRI (DCE MRI) of indeterminate adnexal masses. Br J Radiol. 2014;87(1043):20130730.
Thomassin-Naggara I, Balvay D, Rockall A, Carette MF, Ballester M, Darai E, Bazot M. Added Value of Assessing Adnexal Masses with Advanced MRI Techniques. Biomed Res Int. 2015; 2015:785206.
Saini A, Dina R, McIndoe GA, Soutter WP, Gishen P, deSouza NM. Characterization of adnexal masses with MRI. AJR Am J Roentgenol. 2005;184:1004-9.
Mohaghegh P, Rockall AG. Imaging strategy for early ovarian cancer: characterization of adnexal masses with conventional and advanced imaging techniques. Radiographics. 2012; 32:1751-73.
Thomassin-Naggara I, Aubert E, Rockall A, Jalaguier-Coudray A, Rouzier R, Daraï E, Bazot M. Adnexal masses: development and preliminary validation of an MR imaging scoring system. Radiology. 2013;267:432-43.
Ruiz M, Labauge P, Louboutin A, Limot O, Fauconnier A, Huchon C. External validation of the MR imaging scoring system for the management of adnexal masses. Eur J Obstet Gynecol Reprod Biol. 2016;205:115-9.
Haggerty AF, Hagemann AR, Chu C, Siegelman ES, Rubin SC. Correlation of pelvic magnetic resonance imaging diagnosis with pathology for indeterminate adnexal masses. Int J Gynecol Cancer. 2014;24:1215-21.
Kyriazi S, Kaye SB, deSouza NM. Imaging ovarian cancer and peritoneal metastases--current and emerging techniques. Nat Rev Clin Oncol. 2010 Jul;7(7):381-93
Kyriazi S, Collins DJ, Messiou C, Pennert K, Davidson RL, Giles SL, Kaye SB, Desouza NM. Metastatic ovarian and primary peritoneal cancer: assessing chemotherapy response with diffusion-weighted MR imaging--value of histogram analysis of apparent diffusion coefficients. Radiology. 2011 Oct;261(1):182-92.