Benign and Suspicious Ovarian Masses-MR Imaging Criteria for Characterization: Pictorial Review

Pattern Recognition or Adnexal MR Scoring System: Which Is More Accurate in Evaluating Adnexal Lesions?

PURPOSE

This study aims to compare the accuracy of the ADNEX MR scoring system and pattern recognition system to evaluate adnexal lesions indeterminate on the US exam.

METHODS

In this cross-sectional retrospective study, pelvic DCE-MRI of 245 patients with 340 adnexal masses was studied based on the ADNEX MR scoring system and pattern recognition system.

RESULTS

ADNEX MR scoring system with a sensitivity of 96.6% and specificity of 91% has an accuracy of 92.9%. The pattern recognition system's sensitivity, specificity, and accuracy are 95.8%, 93.3%, and 94.7%, respectively. PPV and NPV for the ADNEX MR scoring system were 85.1 and 98.1, respectively. PPV and NPV for the pattern recognition system were 89.7% and 97.7%, respectively. The area under the ROC curve for the ADNEX MR scoring system and pattern recognition system is 0.938 (95% CI, 0.909-0.967) and 0.950 (95% CI, 0.922-0.977). Pairwise comparison of these AUCs showed no significant difference (p = 0.052).

CONCLUSION

The pattern recognition system is less sensitive than the ADNEX MR scoring system, yet more specific.

Radiomics in the CT diagnosis of ovarian cystic malignancies - a pilot study

Background and aims

The conventional computed tomography (CT) appearance of ovarian cystic masses is often insufficient to adequately differentiate between benign and malignant entities. This study aims to investigate whether texture analysis of the fluid component can augment the CT diagnosis of ovarian cystic tumors.

Methods

Eighty-four patients with adnexal cystic lesions who underwent CT examinations were retrospectively included. All patients had a final diagnosis that was established by histological analysis in forty four cases. The texture features of the lesions content were extracted using dedicated software and further used for comparing benign and malignant lesions, primary tumors and metastases, malignant and borderline lesions, and benign and borderline lesions. Texture features' discriminatory ability was evaluated through univariate and receiver operating characteristics analysis and also by the use of the k-nearest-neighbor classifier.

Results

The univariate analysis showed statistically significant results when comparing benign and malignant lesions (the Difference Variance parameter, p=0.0074) and malignant and borderline tumors (the Correlation parameter, p=0.488). The highest accuracy (83.33%) was achieved by the classifier when discriminating primary tumors from ovarian metastases.

Conclusion

Texture parameters were able to successfully discriminate between different types of ovarian cystic lesions based on their content, but it is not entirely clear whether these differences are a result of the physical properties of the fluids or their appartenance to a particular histopathological group. If further validated, radiomics can offer a rapid and non-invasive alternative in the diagnosis of ovarian cystic tumors.

O-RADS MRI risk stratification system: pearls and pitfalls

In 2021, the American College of Radiology (ACR) Ovarian-Adnexal Reporting and Data System (O-RADS) MRI Committee developed a risk stratification system and lexicon for assessing adnexal lesions using MRI. Like the BI-RADS classification, O-RADS MRI provides a standardized language for communication between radiologists and clinicians. It is essential for radiologists to be familiar with the O-RADS algorithmic approach to avoid misclassifications. Training, like that offered by International Ovarian Tumor Analysis (IOTA), is essential to ensure accurate and consistent application of the O-RADS MRI system. Tools such as the O-RADS MRI calculator aim to ensure an algorithmic approach. This review highlights the key teaching points, pearls, and pitfalls when using the O-RADS MRI risk stratification system.Critical relevance statement This article highlights the pearls and pitfalls of using the O-RADS MRI scoring system in clinical practice.Key points• Solid tissue is described as displaying post- contrast enhancement.• Endosalpingeal folds, fimbriated end of the tube, smooth wall, or septa are not solid tissue.• Low-risk TIC has no shoulder or plateau. An intermediate-risk TIC has a shoulder and plateau, though the shoulder is less steep compared to outer myometrium.

Spectrum of Ovarian Incidentalomas: Diagnosis and Management

Incidental ovarian lesions are asymptomatic lesions that are accidentally discovered during a CT or MRI examinations that involves the pelvic cavity or during a routine obstetric ultrasound study. Incidental ovarian masses are usually benign with a very low risk of malignancy yet underlying malignant pathology may be discovered during the diagnostic work-up of these lesions. Suspicion of malignancy is directly correlating with the increase in the patient's age, the increase in the size of the lesion, the presence of the solid components or thick septa and a high color scale of the ovarian mass. Following standard reporting and management protocols are essential to choose the proper work-up of these lesions to avoid unnecessary additional imaging and operative intervention. In this article, we will provide a review of the characteristic imaging features of some incidental and yet commonly encountered ovarian lesions. We will also summarize the recently published algorithms that are important for consistent reporting and standard management of these lesions.

Ovarian Neoplasm: Delivering Suspicion of Cancer in the Emergency Department

Cancer is not infrequently detected in the Emergency Department (ED) and is sometimes even an incidental finding on imaging. Since the ED is designed to identify and treat acutely ill patients, the time providers can spend with patients and the depth of investigation into patient conditions is limited. However, Emergency Medicine physicians must ensure the appropriate follow-up for patients with presumptive diagnosis of cancer to ensure timely confirmatory testing, prompt treatment, and accurate prognosis. A 26-year-old woman presented to the ED for evaluation of abdominal pain and urinary complaints and was ultimately found to have a 36cm ovarian mass that was suspicious for neoplasm. The mass caused obstruction of urinary outflow leading the patient to develop a urinary tract infection. Emergency Medicine physicians are faced with the challenge of having limited time and short-lived doctor-patient relationships. In cases of suspicious findings, balancing the urgency of follow-up without causing undue harm from heightened anxiety for patients is essential. It is important to discuss findings that may be concerning for cancer with both clear verbal and written communication. Employ strategies such as direct communication with primary care physicians and outpatient specialists via phone consultation and electronic medical record messaging, as well as providing clear discharge instructions in-person and in-writing to the patient including whom to call and the time frame for follow-up.

Management of Large Pediatric and Adolescent Ovarian Neoplasms with a Leak-Proof Extracorporeal Drainage Technique: Our Experience Using a Hybrid Minimally Invasive Approach

STUDY OBJECTIVE

In a pediatric setting, laparoscopic management of large cystic ovarian neoplasms with low malignancy probability is not suitable, because of the mass size; nevertheless, an effort should be made to be as minimally invasive as possible, without violating the principles of oncologic surgery. We describe our experience in managing these neoplasms with leak-proof extracorporeal drainage through mini laparotomy, followed by cyst excision or oophorectomy.

DESIGN

Case series study, describing interventions and outcomes.

SETTING

Department of pediatric surgery in a tertiary pediatric and adult university hospital.

PARTICIPANTS

Pediatric patients affected by large cystic ovarian mass.

INTERVENTIONS

Hybrid minimally invasive approach using leak-proof extracorporeal drainage.

MAIN OUTCOME MEASURES

Data on demographic characteristics, tumor marker values, and imaging findings were collected and analyzed. Outcome of surgical technique was evaluated and reported.

RESULTS

Between 2011 and 2018, 17 patients (mean age, 10.2 years; range, 2-14 years) affected by large cystic ovarian mass, were eligible for this technique. All patients had negative preoperative tumor markers. Of the seventeen subjects, 13/17 girls (76%) underwent pelvic magnetic resonance imaging. No sign of lymphadenopathy or metastasis was found. Surgery was successful in all patients, with ovarian preservation in 5/17 cases (29.4%). Mean surgical time was 98 minutes; no intra-abdominal leakage of neoplasm content or postoperative complications occurred. Mature cystic teratoma was the most frequent histopathological diagnosis (71%).

CONCLUSION

After a thorough patient selection, the management of large cystic ovarian neoplasms with leak-proof extracorporeal drainage performed through a mini laparotomy is a feasible and safe approach, with excellent cosmetic results. When achievable, ovarian-sparing surgery has to be considered.

The diagnostic value of magnetic resonance imaging in differentiating benign and malignant pediatric ovarian tumors

BACKGROUND

The diagnostic workup of ovarian tumors in children and adolescents is challenging because preserving fertility, in addition to oncological safety, is of particular importance in this population. Therefore, a thorough preoperative assessment of ovarian tumors is required.

OBJECTIVE

To investigate the diagnostic value of MR imaging in differentiating benign from malignant ovarian tumors in children and adolescents.

MATERIALS AND METHODS

We conducted a retrospective study of all children and adolescents age <18 years who underwent MR imaging of ovarian tumors during 2014-2019 at a pediatric specialty center. Two radiologists reviewed all MR imaging. We used pathology reports to define the histological diagnosis.

RESULTS

We included 30 girls who underwent MR imaging for an ovarian tumor. Signs indicative for malignancy were tumors with a diameter ≥8 cm, with areas of contrast enhancement, irregular margins, extracapsular tumor growth, and ascites. All benign and malignant ovarian tumors were correctly identified by the radiologists.

CONCLUSION

The diagnostic utility of MR imaging in classifying ovarian tumors in children and adolescents as benign or malignant is promising and might aid in defining the indication for ovarian-sparing versus non-ovarian-sparing surgery. We recommend evaluating these tumors with MR imaging prior to deciding on surgical treatment.

Adnexal masses characterized on 3 tesla magnetic resonance imaging - added value of diffusion techniques

Background

To assess different types of adnexal masses as identified by 3T MRI and to discuss the added value of diffusion techniques compared with conventional sequences.

Patients and methods

174 women age between 13 and 87 underwent an MRI examination of the pelvis for a period of three years. Patients were examined in two radiology departments – 135 of them on 3 Tesla MRI Siemens Verio and 39 on 3 Tesla MRI Philips Ingenia. At least one adnexal mass was diagnosed in 98 patients and they are subject to this study. Some of them were reviewed retrospectively. Data from patients’ history, physical examination and laboratory tests were reviewed as well.

Results

124 ovarian masses in 98 females’ group of average age 47.2 years were detected. Following the MRI criteria, 59.2% of the cases were considered benign, 30.6% malignant and 10.2% borderline. Out of all masses 58.1% were classified as cystic, 12.9% as solid and 29% as mixed. Оf histologically proven tumors 74.4% were benign and 25.6% were malignant. All of the malignant tumors had restricted diffusion. 64 out of all patients underwent contrast enhancement. (34 there were a subject of contraindications). 39 (61%) of the masses showed contrast enhancement.

Conclusions

Classifying adnexal masses is essential for the preoperative management of the patients. 3T MRI protocols, in particular diffusion techniques, increase significantly the accuracy of the diagnostic assessment.

Bimodal magnetic resonance and optical imaging of extracellular matrix remodelling by orthotopic ovarian tumours

BACKGROUND

The extracellular matrix modulates the development of ovarian tumours. Currently, evaluation of the extracellular matrix in the ovary is limited to histological methods. Both magnetic resonance imaging (MRI) and two-photon microscopy (2PM) enable dynamic visualisation and quantification of fibrosis by endogenous contrast mechanisms: magnetisation transfer (MT) MRI and second-harmonic generation (SHG) 2PM, respectively.

METHODS

Here, we applied the MT-MRI protocol for longitudinal imaging of the stroma in orthotopic human ovarian cancer ES-2 xenograft model in CD1 athymic nude mice, and for orthotopically implanted ovarian PDX using a MR-compatible imaging window chamber implanted into NSG mice.

RESULTS

We observed differences between ECM deposition in ovarian and skin lesions, and heterogeneous collagen distribution in ES-2 lesions. An MR-compatible imaging window chamber enabled visual matching between T2 MRI maps of orthotopically implanted PDX grafts and anatomical images of their microenvironment acquired with a stereomicroscope and SHG-2PM intravital microscopy of the collagen. Bimodal MRI/2PM imaging allowed us to quantify the fibrosis within the same compartments, and demonstrated the consistent results across the modalities.

CONCLUSIONS

This work demonstrates a novel approach for measuring the stromal biomarkers in orthotopic ovarian tumours in mice, on both macroscopic and microscopic levels.

Imaging in pediatric ovarian tumors

The spectrum of ovarian tumors in the pediatric population differs significantly from that in adults. Germ cell tumors are the predominant class of ovarian tumors in children, whereas epithelial tumors are the most common in adults. Ultrasonography is the modality of choice for the initial evaluation of pediatric ovarian tumors. Determining the diagnosis based on imaging may prove difficult, and combining the imaging findings with the clinical scenario is very helpful in reaching a differential diagnosis during clinical practice. We will discuss the spectrum of ovarian neoplasms in the pediatric population and describe their clinical, pathologic, and imaging characteristics. A few unique entities related to ovarian tumors, such as growing teratoma syndrome, anti-N-methyl-D-aspartate receptor encephalitis, and hereditary ovarian tumor syndromes, are also discussed. In addition, we will review several entities that may mimic ovarian neoplasms as well as their distinct imaging features.

Functional MRI in the pre-operative assessment of GI-RADS 3, 4, and 5 ovarian masses

Background

Characterization of an ovarian lesion is a diagnostic challenge. A correct preoperative assessment is of great importance so as to arrange adequate therapeutic procedures. The aim of the current study is to evaluate the diagnostic performance of functional MRI in differentiation between malignant, borderline, and benign ovarian masses.

Results

This study included 56 adnexal lesions. Bilateral synchronous ovarian lesions are detected in 16 cases. Postoperative histologically proved to be benign in 17 (30%), borderline (low potential malignancy) in 12 (22%), and malignant in 27 (48%). The overall diagnostic performance of conventional MRI in the diagnosis of adenexal lesion was a sensitivity of 74%, specificity of 47%, positive predictive value (PPV) of 76%, negative predictive value (NPV) of 44%, and an accuracy of 66%. Functional pelvic MRI examination showed an increase in overall diagnostic performance compared to conventional values with the highest sensitivity of 90% and NPV of 67% using DWI, and the highest specificity of 88%, PPV of 94%, and an accuracy of 82% using DCE MRI.

Conclusion

Functional MRI in conjugation with conventional MRI plays a key role in the ovarian lesion detection, characterization, and staging. Functional MRI is currently being evaluated as possible predictive and prognostic biomarkers in ovarian lesions.

MR imaging in discriminating between benign and malignant paediatric ovarian masses: a systematic review

OBJECTIVES

The use of magnetic resonance (MR) imaging in differentiation between benign and malignant adnexal masses in children and adolescents might be of great value in the diagnostic workup of sonographically indeterminate masses, since preserving fertility is of particular importance in this population. This systematic review evaluates the diagnostic value of MR imaging in children with an ovarian mass.

METHODS

The review was made according to the PRISMA Statement. PubMed and EMBASE were systematically searched for studies on the use of MR imaging in differential diagnosis of ovarian masses in both adult women and children from 2008 to 2018.

RESULTS

Sixteen paediatric and 18 adult studies were included. In the included studies, MR imaging has shown good diagnostic performance in differentiating between benign and malignant ovarian masses. MR imaging techniques including diffusion-weighted imaging (DWI) and dynamic contrast-enhanced (DCE) imaging seem to further improve the diagnostic performance.

CONCLUSION

The addition of DWI with apparent diffusion coefficient (ADC) values measured in enhancing components of solid lesions and DCE imaging may further increase the good diagnostic performance of MR imaging in the pre-operative differentiation between benign and malignant ovarian masses by increasing specificity. Prospective age-specific studies are needed to confirm the high diagnostic performance of MR imaging in children and adolescents with a sonographically indeterminate ovarian mass.

KEY POINTS

• MR imaging, based on several morphological features, is of good diagnostic performance in differentiating between benign and malignant ovarian masses. Sensitivity and specificity varied between 84.8 to 100% and 20.0 to 98.4%, respectively. • MR imaging techniques like diffusion-weighted imaging (DWI) and dynamic contrast-enhanced (DCE) imaging seem to improve the diagnostic performance. • Specific studies in children and adolescents with ovarian masses are required to confirm the suggested increased diagnostic performance of DWI and DCE in this population.

External validation of ADNEX MR SCORING system: a single-centre retrospective study

AIM

To evaluate the accuracy of the ADNEX MR SCORING system for characterising adnexal masses.

MATERIALS AND METHODS

An institutional review board approved this retrospective study. The study population comprised 663 women who underwent magnetic resonance imaging (MRI) from January 2007 to December 2014 to characterise 778 adnexal masses that were indeterminate under ultrasonography (590 benign and 188 malignant). Two radiologists independently reviewed the MRI images. The masses were scored from 1 to 5 according to the ADNEX MR SCORING system. The diagnostic performance of the system was evaluated by receiver operating characteristic (ROC) analysis. Masses scored 4 or greater were considered malignant (including tumours of borderline malignancy or low malignant potential).

RESULTS

The malignancy rates of masses with scores of 2, 3, 4 and 5 were 1.9% (8/419), 12.8% (19/149), 62.6% (57/91) and 87.4% (104/119) for reader 1 and 2.1% (9/424), 13.6% (20/147), 67.6% (71/105) and 86.3% (88/102) for reader 2, respectively. The areas under the ROC curves for the differentiation of benign and malignant masses were 0.929 and 0.923, respectively; the sensitivity, specificity and accuracy of diagnosis were 85.6% (161/188), 91.7% (541/590), and 90.2% (702/778) for reader 1 and 84.6% (159/188), 91.9% (542/590), and 90.1% (701/778) for reader 2, respectively. Tumours of borderline malignancy or low malignant potential had a higher rate of misclassification (46.1%) than other malignant tumours (6-7.4%).

CONCLUSION

The ADNEX MR SCORING system was highly accurate in differentiating benign and malignant adnexal masses, although it may be less accurate for tumours of borderline malignancy or low malignant potential.

Screening for ovarian cancer: imaging challenges and opportunities for improvement

The United Kingdom Collaborative Trial of Ovarian Cancer Screening (UKCTOCS) recently reported a reduction in the average overall mortality among ovarian cancer patients screened with an annual sequential, multimodal strategy that tracked biomarker CA125 over time, where increasing serum CA125 levels prompted ultrasound. However, multiple cases were documented wherein serum CA125 levels were rising, but ultrasound screens were normal, thus delaying surgical intervention. A significant factor which could contribute to false negatives is that many aggressive ovarian cancers are believed to arise from epithelial cells on the fimbriae of the fallopian tubes, which are not readily imaged. Moreover, because only a fraction of metastatic tumors may reach a sonographically-detectable size before they metastasize, annual screening with ultrasound may fail to detect a large fraction of early-stage ovarian cancers. The ability to detect ovarian carcinomas before they metastasize is critical and future efforts towards improving screening should focus on identifying unique features specific to aggressive, early-stage tumors, as well as improving imaging sensitivity to allow for detection of tubal lesions. Implementation of a three-stage multimodal screening strategy in which a third modality is employed in cases where the first-line blood-based assay is positive and the second-line ultrasound exam is negative may also prove fruitful in detecting early-stage cases missed by ultrasound.

Magnetic Resonance Imaging (MRI) and Transvaginal Ultrasonography (TVU) at Ovarian Pain Caused by Benign Ovarian Lesions

Research goal

The aim of the research is to define the possibilities of TVU and the MRI in the diagnosis of the most common benign ovarian lesions which cause pelvic pain.

Patients and methods

In study were included n=74 patients with pelvic pain, who were examined with TVU and then with an MRI of pelvis. Diagnostic results of all patients (n=74) divided into two groups according to the modality that was performed (TVU results n=74 and MRI results n=74 MRI ). We compared the results of TVU and MRI, and with a pathohistological finding after surgery. TVU test sensitivity and MRI test sensitivity has been made for each pathological entity in particular. The overall sensitivity test of TVU was performed for all pathological entities together. The overall sensitivity test of MRI was performed for all pathological entities together.

Results

TVU demonstrated sensitivity of 83.3% for ectopic pregnancy, 83.3% for ovarian torsion, 84% for endometriotic cyst, 88.2% for hemorrhagic cysts, 58.3% for tubo-ovarian abscesses, 62.5% for dermoid cysts. Overall sensitivity of TVU for all these pathological entities was 78.4%. MRI showed a sensitivity of 100% for ovarian ectopic pregnancy, 83.3% for ovarian torsion, 100% for endometriotic cyst, 100% of hemorrhagic cysts, 83.3% tubo-ovarian abscess, and 87.5% for dermoid cysts. Overall sensitivity of MRI in all of these pathological entities was 94.6%. The analysis using the chi square test shows that there is a significant difference in the sensitivity between the US and MRI in favor of greater overall MRI sensitivity in diagnosing ovarian pain caused by benign lesions. (χ2 = 14.352, df = 9, p = 0.0021).

Conclusion

TVU is the first choice method for ovarian analysis due to the convenience and absence of radiation, and MRI is a very useful modality when TVU's results are confusing and unspecific.

Imaging after treatment in uterine malignancies: Spectrum of normal findings and most common complications

Uterine malignancies account for the majority of gynaecologic cancers. Different treatment options are available depending on histology, disease grade and stage. Hysterectomy is the most frequent surgical procedure. Chemotherapy and radiation therapy (CRT) represents the preferred therapeutic choice for locally advanced uterine and cervical malignancies. Imaging of the female pelvis following these treatments is particularly challenging due to alteration of the normal anatomy. Radiologists should be familiar with both the expected post-treatment imaging findings and the imaging features of possible complications to make the correct interpretation and avoid possible pitfalls. The purpose of this review is to show the expected computed tomography (CT) and Magnetic Resonance Imaging (MRI) appearances of the female pelvis following surgery and CRT for uterine and cervical cancer, to illustrate the imaging findings of early and delayed most common complications after surgery and CRT, describing the suitable imaging modalities and protocols for evaluation of patients treated for gynaecologic malignancies.

Magnetic Resonance Imaging of Pelvic Masses: A Compartmental Approach

Magnetic resonance imaging (MRI) is often "one stop shop" for evaluating female pelvic masses that helps in diagnosis, staging, and restaging of these tumors. A pelvic mass can arise from any tissue present within the pelvis. Although most masses in the female pelvis arise from the reproductive organs, masses may also arise from the gastrointestinal tract, urinary system, adjacent soft tissues, peritoneum, etc. It may not always be possible to determine the site of origin or distinguish these masses based on imaging characteristics. However, familiarity with the clinicopathologic and MRI features of most common pelvic masses helps in narrowing the differential diagnosis. Diagnosis of these masses needs a holistic approach as required for any tumor including clinical history, laboratory data, and imaging characteristics. We focus on MRI characteristics of commonly encountered pelvic masses. A compartmental imaging approach is discussed in this article that helps in identifying and characterizing these masses.

Magnetic Resonance Imaging of Gynecological Malignancies: Role in Personalized Management

Gynecological malignancies are a leading cause of mortality and morbidity in women and pose a significant health problem around the world. Currently used staging systems for management of gynecological malignancies have unresolved issues, the most important being recommendations on the use of imaging. Although not mandatory as per the International Federation of Gynecology and Obstetrics recommendations, preoperative cross-sectional imaging is strongly recommended for adequate and optimal management of patients with gynecological malignancies. Standardized disease-specific magnetic resonance imaging protocols help assess disease spread accurately and avoid pitfalls. Multiparametric imaging holds promise as a roadmap to personalized management in gynecological malignancies. In this review, we will highlight the role of magnetic resonance imaging in cervical, endometrial, and ovarian carcinomas.

Endometrioid adenocarcinoma of the ovary: MRI findings with emphasis on diffusion-weighted imaging for the differentiation of ovarian tumors

BACKGROUND

Preoperative differentiation of ovarian malignant tumors still remains a challenge. Diffusion-weighted imaging (DWI) provides information about cellularity of the lesion and might facilitate discrimination between different malignant ovarian lesions.

PURPOSE

To evaluate magnetic resonance imaging (MRI) findings of endometrioid adenocarcinoma of the ovary and to determine the value of DWI in the differential diagnosis of malignant and benign adnexal tumors.

MATERIAL AND METHODS

The following MRI findings were reviewed in 162 patients (21 endometrioid adenocarcinoma, 103 other malignant tumors, 38 benign tumors): lesion size, morphological appearance, T2-weighted (T2W) signal intensity, T1-weighted (T1W) signal intensity, contrast-enhancement pattern, DWI signals with apparent diffusion coefficient (ADC) calculated for b = 800 s/mm(2) in solid tumor components.

RESULTS

The most common morphological appearance was predominantly cystic lesion, found in 90.3% of patients with endometriod adenocarcinoma. The solid parts were slightly hyperintense on T2W images in 19 patients with marked enhancement after contrast administration. No significant difference (P = 0.13) in conventional MRI features was found between endometrioid adenocarcinoma and other malignant ovarian tumors. Hyperintensity on DWI was more frequently observed in malignant tumors than in benign lesions (P < 0.001). ADC values were significantly lower in endometrioid adenocarcinoma than other malignant tumors (0.79 ± 0.21 vs. 0.90 ± 0.19; P = 0.04) and in all malignant lesions compared with benign tumors (0.88 ± 0.31 vs. 1.33 ± 0.17; P < 0.001).

CONCLUSION

DWI with ADC measurement could indicate the presence of endometrioid adenocarcinomas due to a slightly but significantly lower ADC values compared to other malignant ovarian lesions. Thus, DWI is beneficial and should be part of a standard protocol for the evaluation of indeterminate adnexal lesions.

Magnetic resonance imaging features of ovarian fibroma, fibrothecoma, and thecoma

OBJECTIVE

To retrospectively evaluate the conventional and functional (diffusion- or perfusion-weighted) magnetic resonance (MR) imaging features of ovarian fibroma, fibrothecoma, and thecoma.

MATERIALS AND METHODS

Histologically proven ovarian fibromas (n = 19), fibrothecomas (n = 7), and thecomas (n = 2) were reviewed (26 patients). The morphologic and signal intensity (SI) characteristics on conventional MR imaging (n = 28, all cases) were analyzed. The b 1000 signal intensity on diffusion-weighted image (DWI) (n = 22) and the time-to-signal intensity curve on perfusion-weighted image (PWI) (n = 7) were also analyzed. The presence and shape of the ipsilateral ovarian tissue surrounding the lesions were evaluated on T2-weighted image.

RESULTS

Twenty-two cases (79%) were predominantly solid tumor. Majority of the detected lesions exhibited the characteristic homogeneous low SI on T1- (24/28, 86%) and T2- (19/28, 68%) weighted image. Conversely, a number of lesions exhibited high SI (9/28, 32%) on T2-weighted image. Most lesions presented with a detectable ipsilateral ovary on T2-weighted image (24/28, 86%). Tumors larger than 6 cm more likely showed atypical morphology (mixed solid and cystic, cystic), atypical SI (high on T1- and T2-weighted image), and large amount ascites. Larger tumor group (>6 cm) was more likely diagnosed as fibrothecoma or thecoma than fibroma by pathology. On DWI, 16 lesions showed low b 1000 signal intensity (16/22, 73%). On PWI, all lesions showed curve type 1 or 2 (7/7, 100%), which tends to characterize benign lesions. All (16/16, 100%) pre-menopausal women had a detectable ipsilateral ovary, and six (60%) out of 10 post-menopausal women had a detectable ipsilateral ovary (p < 0.05).

CONCLUSIONS

Combining conventional morphologic and signal intensity characteristics with the findings from DWI or PWI might help differentiate ovarian fibroma, fibrothecoma, and thecoma from ovarian malignancy, although further prospective larger scale study using DWI and PWI is needed.

MR imaging of ovarian masses: classification and differential diagnosis

OBJECTIVE

We propose a Magnetic Resonance Imaging (MRI) guided approach to differential diagnosis of ovarian tumours based on morphological appearance.

BACKGROUND

Characterization of ovarian lesions is of great importance in order to plan adequate therapeutic procedures, and may influence patient's management. Optimal assessment of adnexal masses requires a multidisciplinary approach, based on physical examination, laboratory tests and imaging techniques. Primary ovarian tumours can be classified into three main categories according to tumour origin: epithelial, germ cell and sex cord-stromal tumours. Ovarian neoplasms may be benign, borderline or malignant. Using an imaging-guided approach based on morphological appearance, we classified adnexal masses into four main groups: unilocular cyst, multilocular cyst, cystic and solid, predominantly solid. We describe MR signal intensity features and enhancement behaviour of ovarian lesions using pathologically proven examples from our institution.

CONCLUSION

MRI is an essential problem-solving tool to determine the site of origin of a pelvic mass, to characterize an adnexal mass, and to detect local invasion. The main advantages of MRI are the high contrast resolution and lack of ionizing radiation exposure. Although different pathological conditions may show similar radiologic manifestations, radiologists should be aware of MRI features of ovarian lesions that may orientate differential diagnosis.

TEACHING POINTS

• Diagnostic imaging plays a crucial role in detection, characterization and staging of adnexal masses. • Characterization of an ovarian lesion may influence patient's management. • Different pathological conditions may have similar radiologic manifestations. • Non-neoplastic lesions should always be taken into consideration.

Role of diffusion-weighted magnetic resonance imaging in differentiating malignancies from benign ovarian tumors

OBJECTIVE

We conducted a case-control study to evaluate the diagnostic values of computed tomography (CT) and diffusion-weighted magnetic resonance imaging (DW-MRI) in differentiating malignancies from benign ovarian tumors and a meta-analysis to further confirm our results on DW-MRI.

METHODS

Totally 64 patients pathologically confirmed as ovarian cancer were included in this study. CT scan and DWI-MRI were performed and analyzed to get compared with pathological results, thereby assessing their accuracy, sensitivity and specificity. Meta-analysis was conducted by database searching and strict eligibility criteria, using STATA 12.0 (Stata Corp, College Station, TX, USA) software.

RESULTS

The accuracy, sensitivity, specificity, positive predictive value and negative predictive value for diagnosis of ovarian cancer in CT were 81.82%, 84.48%, 76.67%, 87.50% and 71.88%, respectively; those in DW-MRI were 89.77%, 93.10%, 83.33%, 91.53% and 86.21%, respectively. The Kappa coefficient of DW-MRI (K = 0.771) compared with pathological results was higher than CT (K = 0.602). The average apparent diffusion coefficient values of DW-MRI in diagnosis of benign and malignant ovarian tumors suggested statistically significant difference (1.325 ± 0.269×10(-3) mm(2)/s vs. 0.878 ± 0.246×10(-3) mm(2)/s, P < 0.001). Meta-analysis results showed that the combined sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and diagnostic odds ratio of DW-MRI in discriminating benign versus malignant ovarian tumors were 0.93, 0.88, 7.70, 0.08 and 101.24, respectively. The area under the summary receiver operating characteristic curve was 0.95.

CONCLUSIONS

Both CT and DW-MRI were of great diagnostic value in differentiating malignancies from benign ovarian tumors, while DW-MRI was superior to CT with higher accuracy, sensitivity and specificity.

Semi-quantitative contrast-enhanced MR analysis of indeterminate ovarian tumours: when to say malignancy?

OBJECTIVE

To evaluate the ability of dynamic post-contrast sequence to specify indeterminate ovarian masses with inconclusive MR features of malignancy. Since management is dramatically different, special focus on the ability to differentiate borderline from invasive malignancy was considered.

METHODS

150 ovarian masses were detected by pelvic ultrasound in 124 patients. Masses had been considered for dynamic post-contrast MRI. We expressed the kinetic parameters (i.e. enhancement amplitude, time peak of maximal uptake and maximal slope) in the form of maximum relative enhancement percentage (MRE%), time of maximal peak of contrast uptake (Tmax) and slope enhancement ratio (SER) curves. Histological findings were the gold standard of reference.

RESULTS

Malignant ovarian masses showed higher MRE% than benign and borderline masses (p < 0.001). Tmax was shorter for malignant than benign (p < 0.01) and borderline (p < 0.001) ovarian masses. SER curves were the most suggestive of malignancy with a specificity and accuracy of 85.7% and 84.7%, respectively.

CONCLUSION

Dynamic contrast-enhanced MRI could be a specific sequence to differentiate ovarian masses with indeterminate MR morphology with a special discrimination for low potential from invasive ovarian malignancy.

ADVANCES IN KNOWLEDGE

The study evaluated the diagnostic performance of the individual parameters of dynamic post-contrast MR sequence in evaluating ovarian masses. Management divert between benign, borderline and invasive malignant masses; our work presented a cut-off value for the peak of contrast uptake of 120%, which helped in the differentiation between benign and malignant tumours; the SER curves with Type III (early washout) pattern that was indicative of invasive malignancy was more specific than borderline malignancy.

Spontaneous T1-Hyperintensity Within an Ovarian Lesion: Spectrum of Diagnoses

Whenever elevated signal intensity is displayed at magnetic resonance imaging (MRI) within an ovarian lesion on unenhanced T1-weighted sequences, some specific diagnoses should be considered because only 3 main components may be responsible for this T1-hyperintensity at MRI: fat, blood products, and proteinaceous or mucinous material. The associated clinical data and concomitant use of T2-weighted sequences and fat-saturation techniques is mandatory to make this tissue characterization possible. The goal of this pictorial review is to provide a simple radiologic reasoning and the differential diagnoses to consider in the presence of spontaneous elevated signal intensity on T1-weighted sequences within a cystic or solid ovarian tumour.

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.

Ovarian cancer: in search of better marker systems based on DNA repair defects

Ovarian cancer is the fifth most common female cancer in the Western world, and the deadliest gynecological malignancy. The overall poor prognosis for ovarian cancer patients is a consequence of aggressive biological behavior and a lack of adequate diagnostic tools for early detection. In fact, approximately 70% of all patients with epithelial ovarian cancer are diagnosed at advanced tumor stages. These facts highlight a significant clinical need for reliable and accurate detection methods for ovarian cancer, especially for patients at high risk. Because CA125 has not achieved satisfactory sensitivity and specificity in detecting ovarian cancer, numerous efforts, including those based on single and combined molecule detection and “omics” approaches, have been made to identify new biomarkers. Intriguingly, more than 10% of all ovarian cancer cases are of familial origin. BRCA1 and BRCA2 germline mutations are the most common genetic defects underlying hereditary ovarian cancer, which is why ovarian cancer risk assessment in developed countries, aside from pedigree analysis, relies on genetic testing of BRCA1 and BRCA2. Because not only BRCA1 and BRCA2 but also other susceptibility genes are tightly linked with ovarian cancer-specific DNA repair defects, another possible approach for defining susceptibility might be patient cell-based functional testing, a concept for which support came from a recent case-control study. This principle would be applicable to risk assessment and the prediction of responsiveness to conventional regimens involving platinum-based drugs and targeted therapies involving poly (ADP-ribose) polymerase (PARP) inhibitors.