Diagnosis of endometriosis with imaging: a review

Delayed diagnosis is associated with changes in the clinical and ultrasound features of subcutaneous endometriosis near cesarean section scars

INTRODUCTION

The aim of the present study was to highlight the sonographic and clinical characteristics of large (≥30 mm in diameter) scar endometriomas near Pfannenstiel incisions, assuming that large size is a marker of delayed diagnosis.

METHODS

We compared clinical, ultrasound (US) and color Doppler findings in 13 patients (mean age 31.3 years) with 13 large scar endometriomas (L-SEs) (mean lesion diameter 41.8 mm; range 30-60 mm) and 17 women (mean age 30.7 years) with 19 small scar endometriomas (S-SEs) (mean lesion size 18.3 mm; range 7-26 mm).

RESULTS

Compared with the S-SE group, the L-SE group had a significantly longer mean interval between the last cesarean section and hospital admission (5.5 vs. 3.3 years; p < 0.01) and longer mean duration of symptoms before admission (43 vs. 17.4 months; p < 0.01). The L-SE group also had a significantly higher percentage of patients who had undergone at least one inconclusive diagnostic examination (Computed Tomography, Magnetic Resonance Imaging, fine needle biopsy, or laparoscopy) (39% vs. 0%; p < 0.05). As for US findings, L-SEs more frequently displayed cystic regions and fistulous tracts (p < 0.05), loss of round/oval shape (p < 0.05), and increased vascularity (p < 0.05).

CONCLUSIONS

Delayed diagnosis of scar endometrioma reflected by a longer and more complex medical history results in larger than usual endometriomas with peculiar US findings, which are even more likely to be misinterpreted by physicians and radiologists.

Evaluation of colonic involvement in endometriosis: double-contrast barium enema vs. magnetic resonance imaging

BACKGROUND

The purpose of the study was to compare the accuracy of double-contrast barium enema (DCBE) and magnetic resonance imaging (MRI) in the diagnosis of intestinal endometriosis using the histological examination on resected specimen as comparative standard.

METHODS

Eighty-three consecutive patients with suspected intestinal endometriosis, resected between 2005 and 2007, were prospectively evaluated. All of the women underwent preoperative DCBE and MRI on the same day. We evaluated number, site (rectum, sigmoid, cecum), and size of the lesions. The imaging findings were correlated with those resulting at pathology.

RESULTS

Among the 65 women who underwent surgery, 50/65 (76.9%) were found to have bowel endometriosis, with 9/50 (18%) patients presenting two lesions; DCBE allowed to detect 50/59 (84.7%) lesions. MRI allowed to detect 42/59 (71.1%) lesions. DCBE showed sensibility, specificity, PPV, NPV, and accuracy of respectively 84.7, 93.7, 98.0, 62.5, and 86.6%, MRI of 71.1, 83.3, 93.3, 46.8, and 74.6%.

CONCLUSION

DCBE is more accurate than unenhanced MRI in the diagnosis of bowel endometriosis, and should be preferred in the preoperative management of this disease, since it usually enables a proper surgical planning.

Endometriomas in the region of a scar from Cesarean section: sonographic appearance and clinical presentation vary with the size of the lesion

PURPOSE

To describe the sonographic (US) appearances of endometriomas developed in the vicinity of a scar from Cesarean section and compare sonographic and clinical characteristics of large (> or =3 cm) scar endometriomas (LSEs) with small scar endometriomas (SSEs).

METHOD

Twenty-eight consecutive women (mean age, 31 years; range, 20-42) with 31 scar endometriomas (mean diameter, 2.7 cm; range, 0.7-6 cm) were examined by US, including color Doppler imaging prior to surgery. Clinical and US findings in women with LSE were compared with those of women with SSE.

RESULTS

Twelve patients had 12 LSEs with a mean longest diameter of 4.1 cm (range, 3-6 cm); in 1 case, a large nodule was associated with a small lesion. Sixteen women had 18 SSEs with a mean lesion size of 1.8 cm (range, 0.7-2.6 cm).The mean time interval between the last Cesarean section and hospital admission was longer in patients with LSE (66 versus 40 months; p < 0.01) as was the mean duration of symptoms before admission (43 versus 17 months; p < 0.01); in addition, 41.6% of patients with LSE had undergone previous inconclusive diagnostic examinations (CT, MRI, fine needle aspiration, or laparoscopy) compared with 0% in patients with SSE (p < 0.05). LSEs more frequently showed cystic portions and fistulous tracts (p < 0.05), loss of round/oval shape (p < 0.05), and increased vascularity (p < 0.05) than SSEs did.

CONCLUSION

LSEs were associated with a delay in diagnosis and some US findings that could result in further diagnostic difficulties.

Dynamic contrast-enhanced MR imaging of ovarian neoplasms: current status and future perspectives

MR imaging is useful for characterizing ovarian tumors. Dynamic contrast-enhanced MR imaging is a promising new technique useful for characterizing perfusion and angiogenesis of ovarian masses. This article describes the dynamic contrast-enhanced MR imaging technique examines the current and future applications of this technique in patients with ovarian tumors.

Transvaginal ultrasound for diagnosis of deeply infiltrating endometriosis

Deeply infiltrating endometriosis is the clinical form of the disease that is generally associated with conditions of more intense pain and may require more complex surgical management, consequently resulting in greater risks to the patient. In recent years, various investigators have confirmed the usefulness of methods such as magnetic resonance imaging (MRI), transrectal ultrasound and transvaginal ultrasound (TVUS) for the diagnosis of deep endometriotic lesions. The objectives of the present study are to describe the method used to perform TVUS for the detection of deeply infiltrating endometriosis, and to discuss the clinical benefits that the data obtained may offer clinicians providing care for patients suspected of having this type of endometriosis.

Role of MRI in Crohn's disease

The traditional imaging of Crohn's disease has relied on barium and computed tomography (CT) examinations. In recent years magnetic resonance imaging (MRI) has emerged as an imaging method that can be used in the diagnosis and assessment of Crohn's disease. The advantages of MRI include lack of ionizing radiation and its superior tissue contrast resolution. The clinical progression of Crohn's disease can be variable, and MRI can be used to assess inflammatory status, disease progression, and complications of Crohn's disease. MRI of the small bowel is an evolving technique and it has the potential to become the preferred technique for imaging of small bowel Crohn's disease in the future.

Value of magnetic resonance imaging for the diagnosis of ovarian tumors: a review

This article reviews the value of magnetic resonance imaging (MRI) for the diagnosis of ovarian tumors especially when ultrasonography is indeterminate. Although ultrasonography is the first imaging technique used to investigate suspected pelvic masses, it has a limited capacity for tissue characterization. In addition to morphological characteristics, many tissue parameters such as T1, T2, perfusion, and diffusion contribute to signal intensity, so MRI is able to identify various types of tissue contained in pelvic masses. Magnetic resonance imaging helps to locate large solid masses and to distinguish benign from malignant ovarian tumors, with an overall accuracy of 88% to 93% for the diagnosis of malignancy. The aims of this review are 3-fold. First, we review state-of-the-art and usual MRI techniques and published findings. Second, we recall the MR features most useful for assessing the main ovarian tumors. Finally, we discuss the relevance of various features for distinguishing between benign, borderline, and invasive ovarian tumors.

Two cases of pregnant women with ovarian endometrioma mimicking a malignant ovarian tumor

The detection of an ovarian mass during pregnancy is often a diagnostic challenge. We describe 2 cases of ovarian endometrioma during pregnancy with marked mural nodules on the cyst wall. The sonographic and MR imaging findings mimicked ovarian cancer. Surgical intervention may still be inevitable to exclude the possibility of malignancy.

Novel noninvasive detection method for endometriosis: research and development of scintigraphic survey on endometrial implants in rats

In this experimental study on endometriosis, the majority of the implants were successfully detected with technetium-(99mTc) labeled red blood cell scintigraphy.

A logistic model for the prediction of endometriosis

OBJECTIVE

To develop a model that uses individual and lesion characteristics to help surgeons choose lesions that have a high probability of containing histologically confirmed endometriosis.

DESIGN

Secondary analysis of prospectively collected information.

SETTING

Government research hospital in the United States.

PATIENT(S)

Healthy women 18-45 years of age, with chronic pelvic pain and possible endometriosis, who were enrolled in a clinical trial.

INTERVENTION(S)

All participants underwent laparoscopy, and information was collected on all visible lesions. Lesion data were randomly allocated to a training and test data set.

MAIN OUTCOME MEASURE(S)

Predictive logistic regression, with the outcome of interest being histologic diagnosis of endometriosis.

RESULT(S)

After validation, the model was applied to the complete data set, with a sensitivity of 88.4% and specificity of 24.6%. The positive predictive value was 69.2%, and the negative predictive value was 53.3%, equating to correct classification of a lesion of 66.5%. Mixed color; larger width; and location in the ovarian fossa, colon, or appendix were most strongly associated with the presence of endometriosis.

CONCLUSION(S)

This model identified characteristics that indicate high and low probabilities of biopsy-proven endometriosis. It is useful as a guide in choosing appropriate lesions for biopsy, but the improvement using the model is not great enough to replace histologic confirmation of endometriosis.

Barium enema evaluation of colonic involvement in endometriosis

OBJECTIVE

The purpose of our study was to define the role of double-contrast barium enema (DCBE) compared with laparoscopy in the diagnosis and local staging of intestinal endometriosis.

MATERIALS AND METHODS

A search of our radiology database revealed the cases of 234 women who underwent surgical resection for pelvic endometriosis with associated intestinal surgery for intestinal endometriosis. We retrospectively evaluated all preoperative DCBE images for the presence of bowel endometriosis and the number, site (rectum, sigmoid, cecum), and size of the lesions. The radiographic findings at DCBE were retrospectively correlated with those at surgical pathologic examination.

RESULTS

DCBE revealed 211 intestinal lesions of bowel endometriosis in 168 (71.8%) of 234 patients with pelvic endometriosis clinically enrolled. Forty (23.8%) of the 168 women had more than one endometriotic bowel nodule (two nodules in 37 cases, three in three cases). Laparoscopy revealed 233 intestinal lesions in 174 (74.3%) of the patients. Fifty-four (31.0%) of 174 women had more than one endometriotic bowel nodule (two nodules in 49 cases, three in five cases). There was 100% correlation between the DCBE and histologic findings as far as site and size of the lesions were concerned. DCBE had a sensitivity of 88.4%, specificity of 93.0%, positive predictive value of 97.5%, negative predictive of 71.0%, and accuracy of 89.5% in the identification of bowel endometriosis.

CONCLUSION

DCBE is helpful in discerning bowel wall involvement in endometriosis, enabling proper surgical planning. DCBE also appears to have a role in the management of endometriosis.

Sonography of endometriosis in infrequent sites

We reviewed the sonographic features of endometriosis in infrequent sites, including the abdominal wall, appendix, perineum, and bladder. Familiarity with the clinical setting and the sonographic appearance of endometriosis in both frequent and infrequent sites can help facilitate prompt, accurate diagnosis and treatment.

Targeting mast cells in endometriosis with janus kinase 3 inhibitor, JANEX-1

Endometriosis (EMS) is a chronic inflammatory disease of multifactorial etiology characterized by implantation and growth of endometrial glands and stroma outside the uterine cavity. EMS is a significant public health issue as it affects 15-20% of women in their reproductive age. Clinical symptoms may include pelvic pain, dysmenorrhea, dyspareunia, pelvic/abdominal masses, and infertility. Symptomatic treatments such as surgical resection and/or hormonal suppression of ovarian function and analgesics are not as effective as desired. Consequently, there is an enormous unmet need to develop effective medical therapy capable of preventing the occurrence and recurrence of EMS without undesirable side-effects. EMS-associated intra-abdominal bleeding episodes, local inflammation, adhesions, and i.p. immunologic dysfunction leads to pelvic nociception and pelvic pain. Increasing evidence supports the involvement of allergic-type inflammation in EMS. Invasion of mast cells, degranulation, and proliferation of interstitial component are observed in endometriotic lesions. Presence of activated and degranulating mast cells within the nerve structures can contribute to the development of pain and hyperalgesia by direct effects on primary nociceptive neurons. Therefore, treatments targeting endometrial mast cells may prove effective in preventing or alleviating EMS-associated symptoms. The Janus kinase 3 (JAK3) is abundantly expressed in mast cells and is required for the full expression of high-affinity IgE receptor-mediated mast cell inflammatory sequelae. JANEX-1/WHI-P131 is a rationally designed novel JAK3 inhibitor with potent anti-inflammatory activity in several cellular and in vivo animal models of inflammation, including mouse models of peritonitis, colitis, cellulitis, sunburn, and airway inflammation with favorable toxicity and pharmacokinetic profile. We hypothesize that JAK3 inhibitors, especially JANEX-1, may prove useful to prevent or alleviate the symptoms of EMS.

Endometriosis of the superior gluteal nerve

Endometriosis that involves nerves is rare and usually occurs in the pelvis. We describe a case of extra-pelvic endometriosis that involved the superior gluteal nerve. The patient presented with ill-defined buttock and thigh pain and a Trendelenberg gait. MRI demonstrated atrophic changes in the gluteus minimus, gluteus medius and tensor fascia lata muscles indicating involvement of the superior gluteal nerve. MRI showed a mass in the line of the superior gluteal nerve. The mass was hyperintense on STIR and T1-weighted images and did not enhance after intravenous contrast although surrounding edema did enhance. Histological examination of material obtained at open biopsy showed endometriosis. The patient was commenced on hormonal treatment to suppress ovarian activity.

Computed Tomographic and Magnetic Resonance Features of Gynecologic Abnormalities in Women Presenting With Acute or Chronic Abdominal Pain

Advances in technology and improved availability have led to increased use of computed tomography (CT) and magnetic resonance imaging (MRI) to evaluate women presenting to the emergency department or to their primary care provider with abdominal and/or pelvic pain. Computed tomographic examinations are often performed to evaluate the presence of appendicitis or renal stone disease. However, gynecologic abnormalities are frequently identified on these examinations. Although ultrasound remains the primary modality by which complaints specific to the pelvis are evaluated, in many instances, CT and MRI imaging occurs before sonographic evaluation.Historically, because of cost, radiation exposure, and relative ease of use, ultrasound examinations have preceded all other imaging modalities when evaluating pelvic disorders. However, as CT and MRI technology have improved, their use in diagnosing causes of pelvic pain has become equal to that of ultrasound. In some cases, primarily because of historic comfort with sonographic evaluation, gynecologic abnormalities originally diagnosed on CT or MRI may be immediately and unnecessarily reevaluated by ultrasound. For a woman in her reproductive years, the most common adnexal masses are physiological cysts, endometriomas, and cystic teratomas. Although lesions are often asymptomatic and incidentally detected, they can present with pain, and they increase the risk of ovarian torsion. Common causes of chronic pelvic pain in this population include leiomyomata and adenomyosis. In postmenopausal women, ovarian carcinoma, which often does not present clinically until a late stage, has to be included in the differential diagnosis of adnexal masses. If a gynecologic pathology is discovered on CT or MRI, an immediate follow-up ultrasound need not be pursued if the lesion can be characterized as benign, needing immediate surgical intervention, or a variant of normal anatomy. If, on the other hand, findings demonstrate a mass that either is uncharacteristic of a benign lesion, has an indeterminate risk for malignancy, or demonstrates suspicious characteristics for malignancy (such as enhancing mural nodules), further evaluation by serial ultrasound, biochemical marker, and/or CT or MRI is warranted. The purpose of this review is to present a series of commonly encountered gynecologic abnormalities with either CT or MR to make radiologists more familiar with gynecologic pathology on CT and MRI.

Using location, color, size, and depth to characterize and identify endometriosis lesions in a cohort of 133 women

OBJECTIVE

To correlate histology with endometriosis characteristics.

DESIGN

Secondary data analysis.

SETTING

Government research hospital.

PATIENT(S)

One hundred thirty-three women with chronic pelvic pain and endometriosis who underwent laparoscopic surgery between 1999 and 2004.

INTERVENTION(S)

Laparoscopic excision of lesions, including recording of lesion characteristics and surgical impression of the lesions.

MAIN OUTCOME MEASURE(S)

All biopsies were sent for histological examination for endometriosis, and surgical and histological findings were compared.

RESULT(S)

Three hundred fifty-seven of 544 lesions believed to be endometriosis by the surgeon had positive histology. Mixed-color lesions most commonly contained endometriosis (76%), with the percentage of positive lesions being similar between single-color groups. Among subtle (red or white) lesions, 58% (164/283) were positive for endometriosis. Thirty women had only red or white lesions, and 18 (60%) had at least one lesion positive for endometriosis. Lesions were most commonly located in the cul-de-sac (64%), utero-sacral ligaments (68%), and ovarian fossa (70%).

CONCLUSION(S)

Wide, deep, mixed-color lesions in the cul-de-sac, the ovarian fossa, or the utero-sacral ligaments had the highest frequency of endometriosis. More than half of subtle lesions had endometriosis. These results should be considered when diagnosing endometriosis.

Magnetic resonance imaging of adnexal masses

Adnexal masses are common in women of all ages. A range of physiological and benign ovarian conditions that develop in women, especially in the reproductive age, and adnexal malignancies can be evaluated with magnetic resonance imaging (MRI). Management of women with adnexal masses is frequently guided by imaging findings; therefore, precise characterization of adnexal pathology should be performed whenever possible. Magnetic resonance imaging is useful in characterization of adnexal masses that are not completely evaluated by ultrasound because it can provide additional information on soft tissue composition of adnexal masses based on specific tissue relaxation times and allows multiplanar imaging at large field of view to define the origin and extent of pelvic pathology. The patients most likely to benefit from MRI are pregnant women and those who are premenopausal and have masses that have complex features on ultrasound but do not have raised cancer antigen 125 tumor marker levels. The overlap in imaging appearance among different cell type malignancies makes it difficult to predict exact histology based on MRI appearance; however, MRI has a high accuracy in differentiating benign from malignant masses. Teratomas, endometriomas, simple and hemorrhagic cysts, fibromas, exophytic or extrauterine fibroids, and hydrosalpinges can be diagnosed with high confidence. In this article, the authors review the histopathologic background and MRI features of adnexal masses and discuss the role of MRI in the differentiation of benign from malignant adnexal pathologies.

Magnetic resonance imaging of the ischiorectal fossa: spectrum of disease

OBJECTIVE

Pelvic magnetic resonance imaging (MRI) studies are widely used to assess the rectum, anal canal, and their environment. The purpose of this article is to review the current role of MRI in the evaluation of diseases involving the ischiorectal fossa and their imaging features.

CONCLUSIONS

The radiologist plays an essential role in the evaluation of some conditions typically located in this space and of other conditions that occasionally involve this area or invade the ischioanal space. The accurate assessment of these diseases that MRI provides further cements its role as the primary technique for the evaluation of pelvic pathology.

From the archives of the AFIP: Inflammatory and nonneoplastic bladder masses: radiologic-pathologic correlation

Although the vast majority of bladder tumors are epithelial neoplasms, a variety of nonneoplastic disorders can cause either focal bladder masses or diffuse mural thickening and mimic malignancy. Some of these entities are rare and poorly understood such as inflammatory pseudotumor, which produces ulcerated, bleeding polypoid bladder masses. These masses may be large and have an extravesical component. Bladder endometriosis manifests as submucosal masses with characteristic magnetic resonance imaging features consisting of hemorrhagic foci and reactive fibrosis. Nephrogenic adenoma has no typical features, and pathologic evaluation is required for diagnosis. Although imaging features of malacoplakia are also nonspecific, characteristic Michaelis-Gutmann bodies are found at pathologic evaluation. The various types of cystitis (cystitis cystica, cystitis glandularis, and eosinophilic cystitis) require pathologic diagnosis. Bladder infection with tuberculosis and schistosomiasis produces nonspecific bladder wall thickening and ulceration in the acute phase and should be suspected in patients who are immunocompromised or from countries where these infections are common. The diagnosis of chemotherapy cystitis and radiation cystitis should be clinically evident, but imaging may be used to determine severity and to assess complications. Extrinsic inflammatory diseases such as Crohn disease and diverticulitis may be associated with fistulas to the bladder and focal bladder wall abnormality. The extravesical findings allow the diagnosis to be made easily. Finally, extrinsic masses arising from the prostate or distal ureter may cause filling defects, which can be confused with intrinsic bladder masses.

Bowel endometriosis: CT-enteroclysis

Although several radiological techniques have been used for the diagnosis of bowel endometriosis, no gold standard is currently established. We used multislice computerized tomography (CT) combined with the distention of the colon by rectal enteroclysis (MSCTe) for the diagnosis of bowel endometriosis. Following bowel preparation, pharmacological hypotonicity, retrograde colonic distention by water enteroclysis, and intravenous injection of iodinated contrast medium, a single volumetric acquisition of the abdomen is performed. MSCTe findings suggestive of bowel endometriosis are the presence of solid nodules with positive enhancement, contiguous or penetrating the colonic wall. When endometriotic lesions are detected, the degree of infiltration of the intestinal wall can be estimated; however, the depth infiltrated by nodules reaching the submucosa may be underestimated. MSCTe is well tolerated by the patients. The strength of MSCT consists in the high spatial resolution; volumetric data acquired by using thin slices provide isotropic voxels and multiplanar reconstructions have a quality comparable with that of the original axial scans. The potential of MSCTe for the diagnosis of bowel endometriosis relies on the fact that the serosal, muscular, and mucosal layers of the bowel wall can be evaluated.

Cine MR imaging of uterine peristalsis in patients with endometriosis

Endometriosis is one of the most important causes of infertility; however the precise mechanism by which it affects female fertility is unclear. The objective of this study was to study the functional aspects of the uterus by evaluating uterine contractility in patients with endometrial cysts of the ovary. The study population was recruited from two institutes and consisted of 26 women (periovulatory (10), luteal (13), and menstrual phase (3); age range: 19-51 years) with untreated endometriosis; the control group consisted of 12 healthy women (age range: 22-41 years). Cine MR imaging obtained by a 1.5T magnet was visually evaluated at 12x faster than real speed, focusing on the presence of uterine peristalsis, the direction and frequency of peristalsis, and the presence of sustained uterine contractions. Uterine peristalsis was identifiable in 3/10, 3/13, and 3/3 of the endometriosis patients in each menstrual cycle, respectively, and in 11/12, 3/12, and 5/12 of their control subjects. Peristaltic detection rate and frequency were significantly less for the endometriosis group than for the controls in the periovulatory phase only (p<0.05). Sustained contractions were recognized in 19/36 control subjects and in 13/26 endometriosis patients, but the difference was not significant. Uterine peristalsis appears to be suppressed during the periovulatory phase in patients with endometriosis, which may have an adverse effect on sperm transport.

Treatment of urinary tract endometriosis

Endometriosis involving the urinary tract, although infrequent, can have significant impact on patients' symptoms, response to treatment, and urologic function. The purpose of this article is to review the epidemiology, pathophysiology, diagnosis, and management of endometriosis that affects the urinary tract.

Multislice CT enteroclysis in the diagnosis of bowel endometriosis

This prospective study aims to evaluate the efficacy of multislice computed tomography combined with colon distension by water enteroclysis (MSCTe) in determining the presence and depth of bowel endometriotic lesions. Ninety-eight women with symptoms suggestive of colorectal endometriosis underwent MSCTe; locations, number of nodule/s, size of the nodule/s and depth of bowel wall infiltration were determined. Independently from the findings of MSCTe, all women underwent laparoscopy. MSCTe findings were compared with surgical and histological results. Abnormal findings suggestive of bowel endometriotic nodules were detected by MSCTe in 75 of the 76 patients with bowel endometriosis. MSCTe identified 110 (94.8%) of the 116 bowel endometriotic nodules removed at surgery; 6 nodules missed at MSCTe were located on the rectum. MSCTe correctly determined the degree of infiltration of the bowel wall in all of the 34 serosal bowel nodules identified at MSCTe. In six nodules reaching the submucosa, the depth of infiltration was underestimated by MSCTe. MSCTe had a sensitivity of 98.7%, a specificity of 100%, a positive predictive value of 100% and a negative predictive value of 95.7% in identifying women with bowel endometriosis. MSCTe is effective in determining the presence and depth of bowel endometriotic lesions.

MR imaging compared with intraoperative frozen-section examination for the diagnosis of adnexal tumors; correlation with final histology

The aim was to compare the accuracy of magnetic resonance imaging (MRI) and intraoperative consultation (IC) for the diagnosis of adnexal masses, with reference to final histology. MRI was performed in 136 women with sonographically indeterminate adnexal masses. IC included macroscopic and frozen-section examination. Macroscopic examination and MRI determined size, nature, and presence of vegetations or solid portions within masses. All masses were characterized as benign or malignant according to previously published MR imaging and histopathologic criteria. Sensitivities, specificities, and predictive values for the diagnosis of malignancy of MRI and IC were assessed. Histology revealed 168 adnexal masses (99 benign, 23 borderline and 46 invasive). Frozen sections were examined in 151 cases. Among the 151 adnexal masses studied by both MRI and IC, respective sensitivities, specificities, positive and predictive values of both methods for the diagnosis of malignancy were 89.7% and 84.5%, 91.4% and 100%, 86.7% and 100%, and 93.4% and 91.3%. Sensitivities of MR imaging and frozen section for the diagnosis of serous versus mucinous borderline tumors were 33.3% and 93.3%, and 62.5% and 12.5%, respectively. MRI is less accurate than IC for characterizing adnexal masses. However, MRI may increase the relevance of IC for borderline mucinous tumors.