Characterization of adnexal mass lesions on MR imaging

Management of epithelial ovarian cancer from diagnosis to restaging: an overview of the role of imaging techniques with particular regard to the contribution of 18F-FDG PET/CT

Epithelial ovarian carcinoma is a major form of cancer affecting women in the western world. The silent nature of this disease results in late presentation at an advanced stage in many patients. It is therefore important to assess the role of imaging techniques in the management of these patients. This article presents a review of the literature on the role of (18)F-FDG-PET/CT in the different stages of management of epithelial ovarian cancer. Moreover, a comparison with other imaging techniques has been made and the relationship between (18)F-PET/CT and the assay of serum CA-125 levels has been discussed.

Primary fallopian tube carcinoma: correlation between magnetic resonance and diffuse weighted imaging characteristics and histopathologic findings

OBJECTIVE

The aim of this study was to investigate the magnetic resonance (MR) and diffusion-weighted (DW) imaging characteristics of primary fallopian tube carcinoma (PFTC).

METHODS

The clinical, MR, and DW imaging characteristics and pathologic findings of 23 patients with 27 tumors were studied retrospectively. The MR and DW imaging appearance of tumors including laterality, size and shape, architecture, signal intensity, apparent diffusion coefficient (ADC) value, enhancement pattern, hydrosalpinx, and intrauterine fluid collection were evaluated and correlated with pathologic findings.

RESULTS

Histopathologically, all 27 tumors were serous carcinoma with a unilateral tumor in 19 patients and bilateral tumors in 4 patients. Thirteen patients (57%) with PFTC were misdiagnosed preoperatively, 10 of which as epithelial ovarian carcinoma. The mean (SD) largest diameter was 61 (7) mm. The tumor shape was fusiform, sausagelike, or serpentine in 19 patients (70%) and nodular or irregular in 8 patients (30%). Twenty (74%) of the 27 tumors were solid, and 7 (26%) were cystic-solid. The solid components showed hypointensity to isointensity on T1-weighted imaging, and isointensity to slight hyperintensity on T2-weighted imaging. There were obvious hyperintensity on DW imaging; obvious hypointensity on ADC maps with a mean (SD) ADC value of 0.79 (0.22) × 10 mm; and mild (8/27, 30%), moderate (13/27, 48%), and marked (6/27, 22%) enhancement on contrast-enhanced imaging. Ipsilateral hydrosalpinx, intrauterine fluid collection, and ascites were found in 14 tumors (52%) and 7 (30%) and 5 (22%) patients, respectively.

CONCLUSIONS

The PFTC has some characteristic MR imaging features. The DW imaging, ADC maps, and ADC values are helpful for the detection and differentiation of PFTC from other pelvic masses.

Magnetic resonance imaging using gadolinium-based contrast agents

The purpose of this article was to review the basic properties of available gadolinium-based magnetic resonance contrast agents, discuss their fundamental differences, and explore common and evolving applications of gadolinium-based magnetic resonance contrast throughout the body excluding the central nervous system. A more specific aim of this article was to explore novel uses of these gadolinium-based contrast agents and applications where a particular agent has been demonstrated to behave differently or be better suited for certain applications than the other contrast agents in this class.

Use of an internal reference in semi-quantitative dynamic contrast-enhanced MRI (DCE MRI) of indeterminate adnexal masses

OBJECTIVE

Semi-quantitative dynamic contrast-enhanced MRI (DCE MRI) has proven useful in discriminating benign from borderline/malignant adnexal lesions. Our aim was to assess if the use of a lesion-to-internal-reference ratio improved the performance in characterizing adnexal masses and which internal reference was suitable.

METHODS

Semi-quantitative DCE MRI images of 71 indeterminate adnexal lesions were retrospectively reviewed. A region of interest was manually drawn onto the enhancing solid component, psoas muscle and normal outer myometrium. The DCE parameters were evaluated, and the lesion-to-internal-reference ratios were calculated.

RESULTS

When the wash in rate of the lesion was higher than that of the myometrium, 97% specificity and 12% sensitivity for borderline/malignancy was reached. When the maximum relative enhancement and maximum absolute enhancement (SImax) of the lesion was less than those of the psoas, 100% specificity for benignity was achieved. The highest area under the curve (AUC) (0.807) was achieved using a SImax lesion-myometrium ratio. A slightly lower AUC (0.799) was achieved using a SImax lesion-psoas ratio, but the psoas muscle was more frequently measurable in the same slice as the lesion ROI. Although the AUC was higher, when using ratios instead of individual DCE values, this was not significantly different.

CONCLUSION

DCE MRI has added diagnostic value in the assessment of adnexal lesions, and the use of internal references enables high specificity for malignancy and benignity. Lesion-internal-reference ratios have no added diagnostic value over DCE values alone.

ADVANCES IN KNOWLEDGE

Both psoas muscle and myometrium are suitable internal references in the DCE assessment of adnexal lesions enabling high specificity for malignancy and benignity.

Lesions of the ovary with T1-hypersignal

Pelvic magnetic resonance imaging (MRI) has been used successfully to diagnose ovarian masses that cannot be adequately evaluated using pelvic ultrasound. T1 hyperintensity is a common finding in an ovarian mass and has important diagnostic implications. The aims of this review are to list the substances that may produce high signal intensity on T1-weighted MRI, to explain the physical basis for causes of the high T1 signal intensity, and to describe common and uncommon T1 hyperintense ovarian lesions. The morphological findings, the imaging features of the additional sequences, and clinical variables can help in the differential diagnosis, and in some cases, enable a specific diagnosis, leading to appropriate management of the patient.

Pelvic MRI as the "gold standard" in the subsequent evaluation of ultrasound-indeterminate adnexal lesions: a systematic review

OBJECTIVE

Incidentally discovered adnexal masses are common, posing a challenging diagnostic problem because imaging features of benign and malignant overlap. Thus, once an adnexal lesion has been detected, the primary goal of further imaging is accurate tissue characterization resulting in surgery only for lesions that are indeterminate or frankly malignant. This study aims to conduct a systematic review, following the PRISMA guidelines, and critically appraise pelvic MR Imaging as the preferred advanced second imaging test, as regards detection of ovarian cancer and assessment of indeterminate adnexal masses, with respect to pre-operatively improving the assignment of these patients to the appropriate level of care.

METHODS

A comprehensive computerized systematic literature search of English language studies was performed (from 2002 to 2012) of PubMed, EMBASE, Scopus, Evidence Based Medicine Reviews (Cochrane Database and Cochrane Central Register of Controlled Trials), and Google Scholar. Relevant article reference lists were hand searched.

RESULTS

Computerized database search revealed 37 citations of relevance, 10 of which fulfilled the inclusion/exclusion criteria. From the aforementioned, 8 articles were acquired (2 authors were contacted but did not respond) as well as assessed with AHRQ, QUADAS, and STARD evaluation tools. Finally, 6 papers (5 prospective and 1 retrospective) were included in the systematic review.

CONCLUSIONS

MRI with intravenous (IV) contrast administration provides the highest post-test probability of ovarian cancer detection. However, the preponderant contribution of MRI in adnexal mass evaluation is its specificity because it provides confident diagnosis of many benign adnexal lesions.

Prospective evaluation of 3T MRI findings for primary adnexal lesions and comparison with the final histological diagnosis

PURPOSE

We prospectively investigated the diagnostic accuracy of magnetic resonance imaging (MRI) at 3.0 Tesla (3T) for the detection of suspected primary adnexal masses in a large cohort of patients.

METHODS

This prospective clinical study included 223 patients with suspected gynaecological disease who were referred for 3T MRI assessments before laparoscopy or laparotomy. Fifty-nine patients were excluded. All detected adnexal pathologies on MRI were categorized into the four groups (endometric cysts, teratomas, benign tumours and malignant tumours). Histological findings were used as the comparative reference standard. As measures to detect or rule out primary adnexal masses, accuracy, sensitivity, specificity, positive predictive values (PPV) and negative predictive values (NPV) were determined by lesion-based evaluations.

RESULTS

The reference standard method detected 141 primary adnexal lesions in 125 patients. The areas under the receiver operating characteristic curve of the lesion-based evaluations for endometric cysts, teratomas, benign lesions and malignant lesions were 92.8, 93.6, 95.1 and 94.4 %. Lesion-based evaluation yielded an accuracy of 90.3 %, sensitivity of 92.7 %, specificity of 89.3 %, PPV of 77.6 % and NPV of 96.8 % in differentiating malignancies from non-malignant lesions. The diagnostic value of 3T MRI for detecting malignancies was superior to that for benign tumours.

CONCLUSIONS

3T MRI well categorize the characteristics of primary adnexal lesions and may be a reliable modality for distinguishing malignancies from benign tumours.

MRI of ovarian masses

MRI provides exquisite views of the pelvic anatomy through its high spatial resolution and tissue contrast, and as such plays a key role in the work up of ovarian lesions, identifying features that distinguish benign and malignant lesions. In the case of primary tumors it enables local staging and detection of metastatic disease to help guide management options such as complex surgery or the consideration of neoadjuvant chemotherapy. Functional MRI techniques such as diffusion-weighted MRI (DW-MRI), dynamic contrast-enhanced MRI (DCE-MRI) and tumor-selective molecular imaging are currently being evaluated as possible predictive and prognostic biomarkers in the context of ovarian malignancy, and may play a larger role in routine clinical practice in the future. Herein we provide an overview of the conventional and advanced MRI techniques used to characterize ovarian masses and of the role that MR plays in the staging, treatment selection and follow up of patients with ovarian cancer.

Value of dynamic contrast-enhanced MRI for tissue characterization of ovarian teratomas: correlation with histopathology

AIM

To analyse the value of double contrast-enhanced (DCE) magnetic resonance imaging (MRI) in addition to conventional MRI to characterize ovarian teratomas subtypes with histological correlation.

MATERIALS AND METHODS

From January 2005 to December 2008, 38 women undergoing MRI and subsequent resection of ovarian teratomas were identified [40 mature cystic teratomas (MCT), two struma ovarii, three immature teratomas]. MRI images were analysed blindly by two radiologists according to morphological and vascular abnormalities. An experienced histopathologist reviewed all slides to determine the presence and histological composition of Rokitansky protuberances.

RESULTS

Thirty-one MCT (77%) had at least one small, regular Rokitansky protuberance presenting at an acute angle with the cyst wall. Ten out of 31 MCT did not display any enhancement on contrast-enhanced MRI related to sebaceous glands, adipose lobules, keratin, and pilosebaceous adnexa at histology. Three different time-intensity curve (TIC), types 1, 2, and 3, were related to presence of smooth muscular cells and fibrous, neuroglial, or thyroid tissue, respectively, found at histology of MCT. Type 3 TIC was also present in one struma ovarii and two immature teratomas.

CONCLUSION

TIC types are related to the specific content of the solid tissue of ovarian teratomas but cannot be used to differentiate benign and malignant ovarian teratomas.

Diseases of the female pelvis: advances in imaging evaluation

Magnetic resonance (MR) imaging has been widely accepted as a powerful imaging modality for the evaluation of the pelvis because of its intrinsic superior soft tissue contrast compared with that of computed tomography. In certain cases, however, the morphologic study provided by MR imaging may not be enough. Functional evaluation with perfusion and diffusion, which allow estimation of the microvascular characteristics and cellularity of the lesions, favors the differentiation of benign from malignant lesions. This article focuses on new magnetic resonance techniques and their contribution to the differentiation and characterization of pelvic pathologies.

The added role of MR imaging in treatment stratification of patients with gynecologic malignancies: what the radiologist needs to know

Many treatment options are available to patients with endometrial, cervical, or ovarian cancer. Magnetic resonance (MR) imaging plays an important role in the patient journey from the initial evaluation of the extent of the disease to appropriate treatment selection and follow-up. The purpose of this review is to highlight the added role of MR imaging in the treatment stratification and overall care of patients with endometrial, cervical, or ovarian cancer. Several MR imaging techniques used in evaluation of patients with gynecologic malignancies are described, including both anatomic MR imaging sequences (T1- and T2-weighted sequences) and pulse sequences that characterize tissue on the basis of physiologic features (diffusion-weighted MR imaging), dynamic contrast agent-enhanced MR imaging, and MR spectroscopy. MR imaging findings corresponding to the 2009 revised International Federation of Gynecology and Obstetrics staging of gynecologic malignancies are also described in detail, highlighting possible pearls and pitfalls of staging. With the growing role of the radiologist as a core member of the multidisciplinary treatment planning team, it is crucial for imagers to recognize that MR imaging has become central in tailoring treatment options and therapy in patients with gynecologic malignancies.

Imaging strategy for early ovarian cancer: characterization of adnexal masses with conventional and advanced imaging techniques

Early detection of ovarian cancer remains crucial for improving patient survival rates. However, early-stage disease is often asymptomatic, and population screening is currently unproven. Adnexal masses may be incidentally detected, but most are identified at ultrasonography (US) in patients who are symptomatic, and most may be characterized as benign or malignant. Indices are available to estimate the risk of malignancy on the basis of clinical and US findings. However, adnexal masses remain indeterminate in some cases, with some benign lesions demonstrating features of malignancy at US. In these cases, use of magnetic resonance (MR) imaging improves the ability to characterize adnexal masses and reduces the number of indeterminate lesions. Establishing the likelihood of malignancy on the basis of imaging features is important to the preoperative detection of early ovarian cancer and profoundly influences referral and management pathways. Conventional and contrast material-enhanced MR imaging are used to evaluate morphologic features, including lesion complexity, signal intensity, and enhancement of solid areas. At dynamic contrast-enhanced MR imaging with semiquantitative analysis, early enhancement characteristics may help differentiate some complex benign and malignant lesions. Diffusion-weighted imaging has a limited but useful role in evaluating adnexal masses: Those with a hypointense solid area on both diffusion-weighted (b = 1000 sec/mm²) and T2-weighted images are likely benign, whereas those that are hyperintense on diffusion-weighted images (b = 1000 sec/mm²) with intermediate signal intensity on T2-weighted images are likely malignant.

Quantitative multiparametric MRI of ovarian cancer

PURPOSE

To identify parameters associated with ovarian malignancy using multiparametric quantitative magnetic resonance imaging (MRI).

MATERIALS AND METHODS

After Institutional Review Board (IRB) approval, women with ovarian masses underwent preoperative imaging with 3 T MRI. Dynamic contrast-enhanced (DCE)-MRI with pharmacokinetic modeling, quantitative T2 mapping, and diffusion-weighted imaging with quantitative mapping of the water diffusion parameters were performed. Ovarian masses had one or more discreet regions of interest, categorized as cystic or solid, and histologically diagnosed as benign or malignant. Mean region of interest (ROI) values were compared between benign and malignant masses using generalized estimating equations. In addition, we compared classification accuracy for the mean ROI value to a combination of histogram characteristics (standard deviation, skewness, and kurtosis) from T2 map ROIs using logistic regression and ROC curve. The significance level was P = 0.05.

RESULTS

Several DCE-MRI parameters differentiated solid benign from malignant masses. Toft's rate constant (kep ) was significantly higher in malignant masses (P < 0.001), as well as quantitative T2 values (P = 0.003), and signal intensity on T2 weighted imaging (P = 0.008). A linear combination of the mean, standard deviation, skewness, and kurtosis of T2 within solid regions (area under the curve [AUC] 0.90) provided better classification accuracy than the mean of T2 alone (AUC 0.81).

CONCLUSION

Quantitative parameters from DCE-MRI and T2 mapping can differentiate benign from malignant ovarian masses.

Pearls and pitfalls in MRI of gynecologic malignancy with diffusion-weighted technique

OBJECTIVE

Developments in MRI techniques have increased the role of MRI in assessment of the pelvis in women. The aims of this review are a short overview of pelvic MRI with an emphasis on diffusion-weighted MRI (DWI) and presentation of a practical approach that includes the pearls and pitfalls of DWI.

CONCLUSION

DWI provides indispensable information in the evaluation of gynecologic malignancies. Prudent application of this technique requires knowledge of the optimal protocols and pitfalls in interpretation.

New MR techniques in gynecologic cancer

OBJECTIVE

Functional MR techniques report on a variety of biologic features of tumors: dynamic contrast-enhanced, diffusion-weighted, and intrinsic susceptibility-weighted MRI and MR spectroscopy reflect, at a simplistic level, vascularity, cellularity, hypoxic status, and metabolism, respectively. This article reviews the evidence for each of the functional MR readouts to determine these clinical end points and thus influence the management of ovarian, endometrial, and cervical cancer.

CONCLUSION

These techniques may be implemented in gynecologic malignancies to detect, characterize, and stage tumors as well as potentially to predict the outcome and measure response to treatment.

Multimodality imaging of ovarian cystic lesions: Review with an imaging based algorithmic approach

Ovarian cystic masses include a spectrum of benign, borderline and high grade malignant neoplasms. Imaging plays a crucial role in characterization and pretreatment planning of incidentally detected or suspected adnexal masses, as diagnosis of ovarian malignancy at an early stage is correlated with a better prognosis. Knowledge of differential diagnosis, imaging features, management trends and an algorithmic approach of such lesions is important for optimal clinical management. This article illustrates a multi-modality approach in the diagnosis of a spectrum of ovarian cystic masses and also proposes an algorithmic approach for the diagnosis of these lesions.

Enhancement of ovarian malignancy on clinical contrast enhanced MRI studies

Purpose. To assess if there is a significant difference in enhancement of high grade serous carcinoma of the ovary compared with other ovarian malignancies on clinically performed contrast enhanced MRI studies. Methods. In this institutional-review–board-approved study, two radiologists reviewed contrast enhanced MRI scans in 37 patients with ovarian cancer. Readers measured the signal intensity (SI) of ovarian mass and gluteal fat pre- and postcontrast administration. Percentage enhancement (PE) was calculated as [(post-pre)/precontrast SI] × 100. Results. Pathology revealed 19 patients with unilateral and 18 patients with bilateral malignancies for a total of 55 malignant ovaries-high grade serous carcinoma in 25/55 ovaries (45%), other epithelial carcinomas in 12 ovaries (22%), nonepithelial cancers in 8 ovaries (14%), and borderline tumors in 10 ovaries (18%). Enhancement of high grade serous carcinoma was not significantly different from other invasive ovarian malignancies (Reader 1 P = 0.865; Reader 2 P = 0.353). Enhancement of invasive ovarian malignancies was more than borderline tumors but did not reach statistical significance (Reader 1P = 0.102; Reader 2 P = 0.072). Conclusion. On clinically performed contrast enhanced MRI studies, enhancement of high grade serous ovarian carcinoma is not significantly different from other ovarian malignancies.

Evaluation of primary adnexal masses by 3T MRI: categorization with conventional MR imaging and diffusion-weighted imaging

Background

To investigate the 3.0-Tesla (3 T) magnetic resonance imaging (MRI) characteristics of primary adnexal lesions for discriminating benign from malignant lesions.

Methods

One hundred thirty-nine patients with pathologically proven primary adnexal masses referred for 3 T MRI assessment preoperatively were included. Baseline characteristics, components, and conventional MRI and diffusion-weighted imaging (DWI-MRI) signals were recorded and compared.

Results

There were 22 ovarian cysts, 33 endometriomas, 43 benign tumors and 42 malignant tumors. When ovarian cyst and endometrioma were excluded, there were no significant differences in patients’ age between benign and malignant tumor (P = 0.235). There were no significant differences (P = 0.606) in the conventional MRI signals and significant difference (P = 0.008) in DWI-MRI signal between the non-malignant and malignant lesions. There was a significant difference (P = 0.000) in the apparent diffusion coefficient values (ADCs) between the non-malignant and malignant lesions.

Conclusions

3 T MRI categorized the characteristics of primary adnexal lesions. Conventional MRI signals were not useful for characterizing between benign and malignant lesions. DWI-MRI and ADCs were helpful for distinguishing malignant from benign ovarian lesions.

Diagnostic accuracy of diffusion-weighted imaging with conventional MR imaging for differentiating complex solid and cystic ovarian tumors at 1.5T

Background

Preoperative characterization of complex solid and cystic adnexal masses is crucial for informing patients about possible surgical strategies. Our study aims to determine the usefulness of apparent diffusion coefficients (ADC) for characterizing complex solid and cystic adnexal masses.

Methods

One-hundred and 91 patients underwent diffusion-weighted (DW) magnetic resonance (MR) imaging of 202 ovarian masses. The mean ADC value of the solid components was measured and assessed for each ovarian mass. Differences in ADC between ovarian masses were tested using the Student’s t-test. The receiver operating characteristic (ROC) was used to assess the ability of ADC to differentiate between benign and malignant complex adnexal masses.

Results

Eighty-five patients were premenopausal, and 106 were postmenopausal. Seventy-four of the 202 ovarian masses were benign and 128 were malignant. There was a significant difference between the mean ADC values of benign and malignant ovarian masses (p < 0.05). However, there were no significant differences in ADC values between fibrothecomas, Brenner tumors and malignant ovarian masses. The ROC analysis indicated that a cutoff ADC value of 1.20 x10^-3 mm²/s may be the optimal one for differentiating between benign and malignant tumors.

Conclusions

A high signal intensity within the solid component on T2WI was less frequently in benign than in malignant adnexal masses. The combination of DW imaging with ADC value measurements and T2-weighted signal characteristics of solid components is useful for differentiating between benign and malignant ovarian masses.

Is MRI a useful tool to distinguish between serous and mucinous borderline ovarian tumours?

AIM

To analyse the morphological magnetic resonance imaging (MRI) features of borderline ovarian tumours (BOT) and to evaluate whether MRI can be used to distinguish serous from mucinous subtypes.

MATERIALS AND METHODS

A retrospective study of 72 patients who underwent BOT resection was undertaken. MRI images were reviewed blindly by two radiologists to assess MRI features: size, tumour type, grouped and irregular thickened septa, number of septa, loculi of different signal intensity, vegetations, solid portion, signal intensity of vegetations, normal ovarian parenchyma, and pelvic ascites. Statistical analysis was performed using Mann-Whitney and Fisher's exact tests. Logistic regression analysis was used to assess the predictive value of the MRI findings for histological subtypes.

RESULTS

At histology, there were 33 serous BOT (SBOT) and 39 mucinous BOT (MBOT). Predictive MRI criteria for SBOT were bilaterality, predominantly solid tumour, and the presence of vegetations, especially exophytic or with a high T2 signal (p < 0.01), whereas predictive MRI criteria for MBOT were multilocularity, number of septa, loculi of different signal intensity, and grouped and irregular thickened septa (p < 0.01). Using multivariate analysis, vegetations were independently associated with SBOT [odds ratio (OR) = 29.5] and multilocularity with MBOT (OR = 3.9).

CONCLUSION

Vegetations and multilocularity are two independent MRI features that can help to distinguish between SBOT and MBOT.

Diffusion-weighted MRI: a useful technique to discriminate benign versus malignant ovarian surface epithelial tumors with solid and cystic components

PURPOSE

To evaluate differences in apparent diffusion coefficient (ADC) values for the solid component of benign and malignant ovarian surface epithelial tumors with the goal of differentiating benign versus malignant ovarian tumors preoperatively.

MATERIALS AND METHODS

A total of 127 patients with 131 pelvic masses identified by ultrasound between January 2006 and January 2011 were enrolled in this study. 46 patients were diagnosed with benign tumors, and 85 patients were diagnosed with malignant pathologies. For all of the patients, routine spin-echo MRI and diffusion-weighted imaging were performed. ADC values were determined for all of the masses, and the mean ADC values for the benign and malignant tumors were analyzed using Student's t test. A P value <0.05 was considered statistically significant.

RESULTS

Mean ADC values associated with malignant ovarian surface epithelial tumors were significantly lower than the mean ADC values of the benign tumors. In addition, the range of ADC values associated with a 95% confidence interval did not overlap between the two groups. ROC analysis indicated that a cutoff ADC value of 1.25 × 10(-3) mm(2)/s was associated with 90.1% sensitivity and 89.9% specificity.

CONCLUSION

ADC values determined from 1.5 T MR DWI of benign and malignant ovarian masses were found to be significantly different.

Radiological manifestations of metastasis to the ovary

MRI is an effective tool for detection of ovarian neoplastic lesions. However, there are no highly specific radiological features that differentiate primary from metastatic ovarian masses. Histological diagnosis preoperatively is not always possible as there is a risk of disseminating an otherwise early stage primary ovarian cancer. The preoperative diagnosis of an ovarian lesion is therefore heavily dependent on the radiological features. The radiologist must rely on a combination of knowing the natural history of any known primary cancer, together with the radiological features such as bilaterality, mucinous appearance, pseudomyxoma as well as the clinical progress of the primary tumour in order to evaluate and predict the likelihood of metastatic disease. Even if a non-ovarian primary cancer is known, an ovarian mass cannot always be assumed to be a secondary lesion. Some tumours, such as BRAC-positive breast cancer, are known to have a high rate of concomitant primary ovarian cancer. Conversely, other tumours, such as gastric and appendiceal cancer, are known to have a high rate of ovarian metastatic disease. However, histology remains the only true way to determine an ovarian metastasis from a primary lesion.

The MRI features of histologically proven ovarian cystadenofibromas-an assessment of the morphological and enhancement patterns

OBJECTIVES

To assess the morphological and enhancement features of histologically proven cystadenofibromas (CAFs) on magnetic resonance imaging (MRI).

METHODS

Forty-seven histologically proven CAFs (42 benign, five borderline) were retrospectively reviewed. One benign CAF had a synchronous adenocarcinoma in the same ovary. The morphological, signal and enhancement characteristics on MRI were recorded.

RESULTS

The mean long axis diameter of the CAFs was 80 mm. The contralateral ovary was abnormal in 45 % of cases. A solid component was seen in 85 %, which returned low T2-weighted signal in 75 % of CAFs. Septa were seen in 74 % and one CAF was purely cystic. The majority of solid components and septa demonstrated enhancement that was less than the myometrium. Wash-in rates (WIR) of the solid tissue were available for measurement in nine patients with an average WIR of 3.2 l/s.

CONCLUSION

This is the largest series describing MRI appearances of histologically proven CAFs. They are typically complex adnexal lesions containing septa, cystic components and solid tissue. The majority of solid components demonstrate low T2 signal and minimal enhancement. Almost half of the cases have an abnormal contralateral ovary.

Incidental pelvic lesions in the oncology patient

The identification of an incidental (i.e. unexpected and asymptomatic) lesion can create a dilemma for the clinician and radiologist. The incidental abnormality may represent metastatic disease, a second primary malignancy or a benign lesion. The diagnosis and management of such incidental findings will depend in part on the clinical setting, the pathology and stage of underlying primary malignancy and the imaging features of the incidental abnormality. This article reviews the diagnosis and management of incidental pelvic lesions in the oncology patient.

Perfusion fraction of diffusion-weighted MRI for predicting the presence of blood supply in ovarian masses

PURPOSE

To evaluate whether perfusion fraction (PF) calculated with diffusion-weighted magnetic resonance imaging (MRI) predicts the presence of blood supply in ovarian masses.

MATERIALS AND METHODS

PFs of 92 ovarian lesions in 53 patients administered gadolinium were retrospectively calculated with diffusion-weighted images at b-values of 0, 500, and 1000 sec/mm(2). PFs were compared between ovarian lesions, except for fat, with (n = 21) or without contrast enhancement (n = 57), using Student's t-test and receiver operating characteristics (ROC) curve analysis. Lesion enhancement rates of contrast-enhanced images at 30 and 180 seconds after gadolinium injection (ER(30sec) and ER(180sec)) and PFs were compared using Pearson's correlation coefficient.

RESULTS

PFs of the lesions with contrast enhancement were significantly higher than those without contrast enhancement (0.22 ± 0.09 and 0.02 ± 0.08, respectively, P < 0.0001). The ROC curve identified the best cutoff point for PF at 0.135 (95.2% sensitivity and 94.7% specificity) as a predictor of the contrast enhancement effect. The area under the ROC curve was 0.984. PF correlated moderately with ER(30sec) (0.62, y = 0.13x + 0.04, P < 0.0001) and ER(180sec) (0.74, y = 0.13x + 0.03, P < 0.0001).

CONCLUSION

PF calculated with diffusion-weighted images can potentially predict blood supply in ovarian masses.

Accuracy of 64-multidetector computed tomography in diagnosis of adnexal tumors

BACKGROUND

Adnexal cancers are in fifth place among the tumors with the highest mortality in the female population. The aim of the present study was to evaluate the accuracy of Multi-detector computed tomography (MDCT) on a 64-multislice CT scanner in the detection and differentiation of adnexal masses stages.

METHODS

During the present prospective study, 95 women with a primary diagnosis of ovarian mass in base of clinical examination and ultrasonographic findings underwent preoperative evaluation by a 64-slice MDCT with a section thickness of 0.6 mm, 50% overlap and reconstructed images. Afterward, results of MDCT were compared with surgical and histopathological findings, and the sensitivity, specificity, positive and negative predictive value and accuracy were determined.

RESULTS

The mean age of patients was 48.63 ± 13.93 years. MDCT diagnosed 25 (26.3%) masses to be benign and 70 (73.7%) to be malignant (sensitivity, specificity, positive and negative predictive value and accuracy were 92.8%, 88.0%, 95.5%, 81.4% and 91.5% respectively). The sensitivity and specificity of MDCT in determining local extension was 72.2% and 93.4% respectively. And the sensitivity and specificity of MDCT in determining peritoneal seeding and liver extension was 81.8% and 93% respectively. Estimated stage was significantly agreed with the surgical (Cohen's Kappa (κ) = 0.891) and histopathological findings (κ = 0.858).

CONCLUSION

MDCT is a highly sensitive and specific diagnostic method in evaluation of adnexal masses and successfully stage the tumor in consistent with surgery and histopathology.

The role of dynamic contrast-enhanced and diffusion weighted magnetic resonance imaging in the female pelvis

Functional imaging by means of dynamic multiphase contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusion weighted magnetic resonance imaging (DW-MRI) is now part of the standard imaging protocols for evaluation of the female pelvis. DCE-MRI and DW-MRI are important MR imaging techniques which enable the radiologist to move from morphological to functional assessment of diseases of the female pelvis. This is mainly due to the limitations of morphologic imaging, particularly in lesion characterization, accurate lymph node staging, assessment of tumour response and inability to differentiate post-treatment changes from tumour recurrence. DCE-MRI improves the accuracy of T2WI in staging of endometrial cancer. It also helps differentiate tumour recurrence from radiation fibrosis in patients with cervical cancer. DCE-MRI improves characterization of cystic adnexal lesions and detection of small peritoneal implants in patients with ovarian cancer. DW-MRI is valuable in preoperative staging of patients with endometrial and cervical cancer, especially in detection of extra-uterine disease. It does increase reader's confidence for detection of recurrent disease in gynaecological malignancies and improves detection of small peritoneal implants in patients with ovarian cancer. In this review article we give an overview of both DCE-MRI and DW-MRI techniques, concentrating on their main clinical application in the female pelvis, and present a practical approach of the added value of these techniques according to the main pathological conditions, highlighting the pearls and pitfalls of each technique.

MRI of the female pelvis: a possible pitfall in the differentiation of haemorrhagic vs. fatty lesions using fat saturated sequences with inversion recovery

The use of fat-saturated techniques should be an integral part of the work-up of any T1-hyperintense structure in the female pelvis for tissue characterization and for differentiation of a fat-containing ovarian mature teratoma from a haemorrhagic lesion. Two cases with haematocolpos and haematometra are presented, respectively. The haemorrhagic content showed high signal both on T1- and T2-weighted images, whereas an unexpected signal decrease in the fat-saturated T2-weighted inversion-recovery sequence was encountered. This unspecific suppression of signal in tissues with similar T1 relaxation times as fat can lead to a diagnostic pitfall both in T1- and T2-weighted STIR pulse sequences. Furthermore, a loss of signal on T2-weighting may also be due to the phenomenon of "T2-shading" in T1-bright ovarian endometrioma. Therefore, the fat-specific spectral fat-saturation of T1-weighted images is strongly recommended for tissue characterization in gynaecological disease.

Radiological staging of ovarian carcinoma

Ovarian cancer is the sixth most commonly diagnosed cancer in the world, accounting for 4% of all female cancers. An estimated 1 in 71 women in the United States will develop ovarian cancer in their lifetime. Accurate staging of ovarian carcinoma is vital in the appropriate management and counseling of patients. The surgical staging proposed by the International Federation of Obstetrics and Gynaecology is the most universally used, and International Federation of Obstetrics and Gynaecology encourages the use of imaging techniques to assess prognostic factors, such as resectable disease and lymph node status. Identifying the volume and locations of tumor is valuable in planning percutaneous tissue biopsy, triaging patients to either primary cytoreductive surgery, or primary platinum-based chemotherapy. Contrast-enhanced computed tomography is the modality of choice for the staging of ovarian carcinoma, with magnetic resonance imaging being used as a problem-solving tool. In this article we discuss and illustrate the staging of ovarian carcinoma, with emphasis on the current imaging modalities and optimal image acquisition.