Indeterminate adnexal masses at ultrasound: effect of MRI imaging findings on diagnostic thinking and therapeutic decisions

Added value of gadolinium-based contrast agents for magnetic resonance evaluation of adnexal torsion in girls

PURPOSE

Ultrasound is the first-line imaging modality to evaluate adnexa in girls with clinical suspicion of torsion. Patients with equivocal ultrasound findings can undergo MRI for better delineation of adnexal pathology. Here, we assess the utility of intravenous contrast in MRI evaluation of adnexal torsion in children.

METHODS

Two pediatric radiologists (R1, R2) retrospectively reviewed 198 pelvic MRI exams in 172 girls (median age 15 years). Each MRI was reviewed twice. The first review included pre-contrast images only. A second review, at least 1 month later, included both pre- and post-contrast images. Readers concluded if findings were suspicious for torsion or not. Readers' findings were compared to each other's and to surgical and MRI reports and clinical course.

RESULTS

198 MRI exams yielded 354 evaluable ovaries. Surgical and pathological reports were available for 47 patients. 11 patients had adnexal torsion. Both readers accurately diagnosed acutely torsed ovaries during pre- and post-contrast reviews (n = 4). However, readers disagreed on torsed paraovarian cysts (n = 4) and chronically/intermittently torsed ovaries (n = 3). In 21 non-torsed ovaries that had lesions, one or both readers concluded that there were pre-contrast features of torsion. In this set with ovarian lesions, contrast helped readers to correctly conclude no torsion (R1 = 8, R2 = 6) more commonly than to incorrectly conclude torsion (1 each), improving post-contrast specificity for each reader.

CONCLUSIONS

Post-contrast sequences did not provide additional benefit in evaluating acutely torsed ovaries but helped in excluding torsion in patients with adnexal lesions. Therefore, contrast administration should be individualized, potentially reserved only for those with abnormal ultrasound or pre-contrast images.

Application of Multimodal Imaging Biomarker in the Differential Diagnosis of Ovarian Mass: Integration of Conventional and Molecular Imaging

PURPOSE

The aim is to investigate the diagnostic performance of multimodal imaging with 18F-FDG PET/CT, MRI, and contrast-enhanced CT (CECT) in cases with unilateral or bilateral ovarian mass without ancillary findings of malignancy.

METHODS

Retrospectively, 307 patients who had unilateral or bilateral ovarian masses and underwent preoperative FDG PET/CT and/or MRI/CECT were included. The criterion standard for the ovarian mass was the final pathology. The peak standardized uptake value (SULpeak) among benign tumors (BTs), borderline ovarian tumors (BoTs), and malignant ovarian tumors (MTs) were compared. The cutoff value of SULpeak to discriminate between BT/BoT and MT was determined from the training (n = 200) and validation (n = 131) cohorts. Diagnostic performances of SULpeak, Ovarian-Adnexal Reporting Data System (O-RADS) MRI score, CECT findings, and combination of multimodal imagings were analyzed.

RESULTS

SULpeak of MT was significantly higher than that of BT or BoT (P < 0.05). There was no significant difference in SULpeak between BT and BoT (P = 0.147). The cutoff value of SULpeak for discriminating between BT/BoT and MT was 1.76 (sensitivity, 87.0%; specificity, 83.0%). Diagnostic performance for BT/BoT versus MT of O-RADS MRI, CECT, FDG PET/CT plus O-RADS MRI score, and FDG PET/CT plus CECT yielded the respective sensitivities of 100%, 94%, 95%, and 82%, and specificities of 43%, 46%, 88%, and 91%, respectively.

CONCLUSIONS

Multimodal imaging biomarkers including FDG PET/CT and MR/CECT could provide additional information to differentiate ovarian masses.

Diagnostic performance of dynamic contrast-enhanced magnetic resonance imaging for malignant ovarian tumors: a systematic review and meta-analysis

BACKGROUND

Accurate preoperative diagnosis of malignant ovarian tumors (MOTs) is particularly important for selecting the optimal treatment strategy and avoiding overtreatment.

PURPOSE

To evaluate the diagnostic efficacy of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for MOTs.

MATERIAL AND METHODS

A systematic search was performed in PubMed, Embase, the Cochrane Library, and Web of Science databases to find relevant original articles up to October 2019. The included studies were assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Studies on the diagnosis of MOTs with quantitative or semi-quantitative DCE-MRI were analyzed separately. The bivariate random-effects model was used to assess the diagnostic authenticity. Meta-regression analyses were performed to analyze the potential heterogeneity.

RESULTS

For semi-quantitative DCE-MRI, the pooled sensitivity, specificity, positive likelihood ratio (LR), negative LR, diagnostic odds ratio (DOR), and the area under the summary receiver operating characteristic curves (AUC) were 85% (95% confidence interval [CI] 0.75-0.92), 85% (95% CI 0.77-0.91), 5.8 (95% CI 3.8-8.8), 0.17 (95% CI 0.10-0.30), 33 (95% CI 18-61), and 0.92 (95% CI 0.89-0.94), respectively. For quantitative DCE-MRI, the pooled sensitivity, specificity, positive LR, negative LR, DOR, and AUC were 88% (95% CI 0.65-0.96), 93% (95% CI 0.78-0.98), 12.3 (95% CI 3.4-43.9), 0.13 (95% CI 0.04-0.45), 91 (95% CI 10-857), and 0.96 (95% CI 0.94-0.98), respectively.

CONCLUSION

DCE-MRI has great diagnostic value for MOTs. Semi-quantitative DCE-MRI may be a relatively mature approach; however, quantitative DCE-MRI appears to be more promising than semi-quantitative DCE-MRI.

Computer Tomography in the Diagnosis of Ovarian Cysts: The Role of Fluid Attenuation Values

Pathological analysis of ovarian cysts shows specific fluid characteristics that cannot be standardly evaluated on computer tomography (CT) examinations. This study aimed to assess the ovarian cysts’ fluid attenuation values on the native (Np), arterial (Ap), and venous (Vp) contrast phases of seventy patients with ovarian cysts who underwent CT examinations and were retrospectively included in this study. Patients were divided according to their final diagnosis into the benign group (n = 32) and malignant group (n = 38; of which 27 were primary and 11 were secondary lesions). Two radiologists measured the fluid attenuation values on each contrast phase, and the average values were used to discriminate between benign and malignant groups and primary tumors and metastases via univariate, multivariate, multiple regression, and receiver operating characteristics analyses. The Ap densities (p = 0.0002) were independently associated with malignant cysts. Based on the densities measured on all three phases, neoplastic lesions could be diagnosed with 89.47% sensitivity and 62.5% specificity. The Np densities (p = 0.0005) were able to identify metastases with 90.91% sensitivity and 70.37% specificity, while the combined densities of all three phases diagnosed secondary lesions with 72.73% sensitivity and 92.59% specificity. The ovarian cysts’ fluid densities could function as an adjuvant criterion to the classic CT evaluation of ovarian cysts.

Radiomic Analysis of MRI Images is Instrumental to the Stratification of Ovarian Cysts

The imaging diagnosis of malignant ovarian cysts relies on their morphological features, which are not always specific to malignancy. The histological analysis of these cysts shows specific fluid characteristics, which cannot be assessed by conventional imaging techniques. This study investigates whether the texture-based radiomics analysis (TA) of magnetic resonance (MRI) images of the fluid content within ovarian cysts can function as a noninvasive tool in differentiating between benign and malignant lesions. Twenty-eight patients with benign (n = 15) and malignant (n = 13) ovarian cysts who underwent MRI examinations were retrospectively included. TA of the fluid component was undertaken on an axial T2-weighted sequence. A comparison of resulted parameters between benign and malignant groups was undertaken using univariate, multivariate, multiple regression, and receiver operating characteristics analyses, with the calculation of the area under the curve (AUC). The standard deviation of pixel intensity was identified as an independent predictor of malignant cysts (AUC = 0.738; sensitivity, 61.54%; specificity, 86.67%). The prediction model was able to identify malignant lesions with 84.62% sensitivity and 80% specificity (AUC = 0.841). TA of the fluid contained within the ovarian cysts can differentiate between malignant and benign lesions and potentially act as a noninvasive tool augmenting the imaging diagnosis of ovarian cystic lesions.

The value of MR-detectable ipsilateral ovaries in characterizing the origin and malignancy of an adnexal tumors

OBJECTIVE

To investigate the magnetic resonance (MR) imaging morphological relationship between adnexal tumors and the ipsilateral ovaries to characterize the origin and malignancy of tumors.

MATERIAL AND METHODS

Clinical and MR imaging data of 496 adnexal tumors confirmed by histology (ovary tumors, n = 400, non-ovarian tumors, n = 96; benign tumors, n = 183, borderline tumors, n = 120, and malignant tumors, n = 193) were retrospectively analyzed. The presence and shape of the ipsilateral ovaries within the context of adnexal tumors of different origins, malignancies and configurations were evaluated. The relationships between the presence of the ipsilateral ovary and patient age, menstrual status and tumor size were also analyzed.

RESULT

The ipsilateral ovary was detected on MRI in 23% (90/400) of ovarian tumors and in 45% (43/96) of non-ovarian tumors (p < 0.001). A normal ovoid morphology of the ipsilateral ovary was found in only 7% (26/400) of ovarian tumors and in 26% (25/96) of non-ovarian tumors (p < 0.001). The ipsilateral ovary was detectable in 38% (69/183) of benign tumors, 35% (42/120) of borderline tumors, and 11% (22/193) of malignant tumors (p <  0.001); in 24% (24/101) of cystic tumors, 27% (49/179) of mixed cystic-solid tumors and 28% (60/216) of solid tumors (p = 0.737); and in 40% (120/303) of adnexal tumors in premenopausal patients and 7% (13/193) of adnexal tumors in postmenopausal patients (p < 0.001).

CONCLUSION

Detection of the ipsilateral ovary contributes to the localization and characterization of adnexal tumors. The ipsilateral ovary can be detected more frequently in non-ovarian tumors and in benign or borderline ovarian tumors.

Magnetic resonance imaging of pediatric adnexal masses and mimics

Evaluation of adnexal masses in children and adolescents relies on imaging for appropriate diagnosis and management. Pelvic MRI is indicated and adds value for all adnexal masses when surgery is considered or when ultrasound findings are indeterminate. Specifically, features on MR imaging can help distinguish between benign and malignant lesions, which not only influences the decision between surgery and conservative treatment, but also the type of surgery to be performed, including potential use of fertility-sparing approaches with minimally invasive techniques. Larger size, younger age, presentation with precocious puberty or virilization, restricted diffusion in a solid mass, and rapid and strong enhancement of solid components are all features concerning for malignancy. In addition, distinctive MR imaging features of adnexal masses, combined with clinical and laboratory biomarkers, might suggest a specific histological diagnosis.

Value of Diffusion-Weighted Magnetic Resonance Imaging in the Characterization of Complex Adnexal Masses

Aims and background

The aim of the study was to define the role of diffusion-weighted imaging in the characterization of adnexal complex masses, with particular regard to the distinction between benign and malignant lesions. Conflicting results on this topic have emerged from studies in the last decade, with a consequent substantial limitation to the use of this relatively novel technique in clinical practice.

Methods and study design

Magnetic resonance imaging examinations performed on 91 patients with ovarian masses (56 benign, 35 malignant) were retrospectively evaluated by two observers unaware of the final histopathological diagnosis. Diffusion-weighted sequences with b values of 0, 500 and 1000 were performed in all cases, and apparent diffusion coefficient maps were automatically generated. The signals of both the cystic and solid components of the ovarian masses were evaluated on T2-weighted and diffusion-weighted images acquired with a b value of 1000. Apparent diffusion coefficient values were measured in all cases.

Results

With regard to the solid components, hypointensity on both the T2-weighted and diffusion-weighted images has proved to be a reliable indicator of benignancy. In contrast, hyperintensity on both sequences was suggestive of malignancy. Signal intensity of the cystic components and apparent diffusion coefficient values of both components have not proven useful in characterization of the masses.

Conclusions

Only the definition of the signal intensities on diffusion-weighted images obtained with the use of high b values on the solid component of a complex adnexal mass is useful to characterize an ovarian mass as benign or malignant.

External validation of the MR imaging scoring system for the management of adnexal masses

OBJECTIVE

To investigate the prognostic value of ADNEX Magnetic Resonance Imaging Scoring in the preoperative management of adnexal masses.

STUDY DESIGN

We performed a retrospective study on patients who underwent surgery for an adnexal mass, with prior exploration by Magnetic Resonance Imaging (MRI), at the Gynecology Department of the Poissy Teaching Hospital between May 2012 and August 2014. MRI data were retrospectively read by radiologists, without knowledge of the histology, and classified according to the criteria of the ADNEX MR score. The radiological presumption of benign or malignant mass was compared with the final histological diagnosis. We calculated the sensitivity, specificity, positive and negative likelihood ratios and ROC curve of the ADNEX MR score with their 95% confidence intervals (95%CI).

RESULTS

One-hundred-and-forty-eight patients were included in the study of which 24 had malignant or borderline ovarian tumors. The proportion of malignant or borderline ovarian tumors in each class of the ADNEX MR score in our study was: ADNEX I: 0% (95%CI, 0-8); ADNEX II: 1.7% (95%CI, 0.04-8.9); ADNEX III: 7.7% (95%CI, 0.2-36); ADNEX IV: 57.1% (95%CI, 34.2-78.8) and ADNEX V: 100% (95%CI, 69.2-100). Thus, for an ADNEX MR score greater than or equal to 4, the sensitivity was 91.7% (95%CI, 73-99) and the specificity 92.7% (95%CI, 86.7-96.6) for the diagnosis of a malignant or borderline ovarian tumor. The area under the ROC curve was 0.92 (95% CI%, 0.86-0.98).

CONCLUSIONS

MRI, coupled with the use of the ADNEX MR scoring system, can accurately classify adnexal masses into low-risk (ADNEX MR score <4) or high-risk (ADNEX MR score ≥4) group, thereby allowing for appropriate preoperative counseling and planning for surgery.

Simulated impact of pelvic MRI in treatment planning for pediatric adnexal masses

BACKGROUND

There are no studies on utility of MRI in management of pediatric adnexal masses.

OBJECTIVE

To determine the diagnostic and therapeutic impact of pelvic MRI in adnexal masses in children and adolescents.

MATERIALS AND METHODS

We included 32 females age 18 years and younger who had adnexal masses and who underwent both pelvic ultrasound (US) and MRI. A radiologist retrospectively reviewed US and MR images and created a standard radiologic report for each patient. In a prospective theoretical fashion, two pediatric gynecologists reviewed the clinical data and US report for each patient and indicated conservative versus surgical management; in surgical cases the options were laparoscopy versus laparotomy, midline versus Pfannenstiel incision, and oophorectomy versus cystectomy. Subsequently, the gynecologists were presented the MRI report and were asked to indicate their treatment options again. A binomial test was conducted to determine the effect of adding MRI findings to the management plan.

RESULTS

The addition of MRI significantly changed management in 10 of 32 patients (P=0.0322), with a change in surgical versus conservative treatment in 5, a change in laparotomy vs. laparoscopy in 2, and a change from oophorectomy to cystectomy along with change in incision in 3 cases. This was based on additional information provided by MRI regarding the nature of the mass in 8 cases and origin of the mass in 2 cases.

CONCLUSION

Preoperative pelvic MRI findings might change the surgical management of pediatric patients with adnexal masses, so it is a valuable addition to the conventional workup in the clinical management.

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.

The Value of Diffusion-Weighted Imaging in the Differential Diagnosis of Ovarian Lesions: A Meta-Analysis

OBJECTIVES

The ability of contrast-enhanced MRI to distinguish between malignant and benign ovarian masses is limited. The aim of this meta-analysis is to evaluate the diagnostic performance of diffusion-weighted imaging (DWI) in differentiating malignant from benign ovarian masses.

METHODS

A comprehensive literature search was performed in several authoritative databases to identify relevant articles. The weighted mean difference (WMD) and corresponding 95% confidence interval (95% CI) were calculated. We also used subgroup analysis to analyze study heterogeneity, and evaluated publication bias.

RESULTS

The meta-analysis is based on 21 studies, which reported the findings for 731 malignant and 918 benign ovarian masses. There was no significant difference in apparent diffusion coefficient (ADC) values for DWI between benign and malignant lesions (WMD = 0.22, 95% CI = -0.02-0.47, p = 0.08). Subgroup analysis by benign tumor type revealed higher ADC values (or a trend toward higher values) for cysts, cystadenomas and other benign tumors compared to malignant masses (cyst: WMD = 0.54, 95% CI = -0.05-1.12, p = 0.07; cystadenoma: WMD = 0.73, 95% CI = 0.38-1.07, p < 0.0001; other benign tumor: WMD = 0.16, 95% CI = -0.13-0.46, p = 0.28). On the other hand, lower ADC values (or a trend toward lower values) were observed for endometrioma and teratoma compared to malignant masses (endometrioma: WMD = -0.09, 95% CI = -0.47-0.29, p = 0.64; teratoma: WMD = -0.49, 95% CI = -0.85-0.12, p = 0.009). Subgroup analysis by mass property revealed higher ADC values in cystic tumor types than in solid types for both benign and malignant tumors. Significant study heterogeneity was observed. There was no notable publication bias.

CONCLUSIONS

Quantitative DWI is not a reliable diagnostic method for differentiation between benign and malignant ovarian masses. This knowledge is essential in avoiding misdiagnosis of ovarian masses.

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.

Magnetic resonance imaging evaluation of non ovarian adnexal lesions

Differentiation of nonovarian from ovarian lesions is a diagnostic challenge. MRI (Magnetic Resonance Imaging) of the pelvis provides excellent tissue characterization and high contrast resolution, allowing for detailed evaluation of adnexal lesions. Salient MRI characteristics of predominantly cystic lesions and predominantly solid adnexal lesions are presented along with epidemiology and clinical presentation. Due to its excellent soft tissue resolution, MRI may be able to characterize indeterminate adnexal masses and aid the radiologist to arrive at the correct diagnosis, thus positively affect patient management.

Added Value of Assessing Adnexal Masses with Advanced MRI Techniques

This review will present the added value of perfusion and diffusion MR sequences to characterize adnexal masses. These two functional MR techniques are readily available in routine clinical practice. We will describe the acquisition parameters and a method of analysis to optimize their added value compared with conventional images. We will then propose a model of interpretation that combines the anatomical and morphological information from conventional MRI sequences with the functional information provided by perfusion and diffusion weighted sequences.

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.

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.

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.

Should less motion sensitive T2-weighted BLADE TSE replace Cartesian TSE for female pelvic MRI?

Objectives

To prospectively compare the diagnostic performance of a non-Cartesian k-space sampling T2-weighted TSE BLADE sequence with a conventional T2-weighted TSE sequence in female pelvic organs.

Methods

Forty-seven patients with sonographically indeterminate adnexal masses or uterine lesions underwent sagittal BLADE and conventional TSE at 1.5 T after glucagon administration. Two radiologists independently determined their preferred sequence by rating: overall image diagnostic quality, conspicuity of the zonal anatomy and delineation of pathologies of the uterus and cervix, presence of artefacts, and of fluid in the pouch of Douglas (Wilcoxon signed rank test). Signal-to noise ratios (SNRs) and contrast-to-noise ratios (CNRs) were measured for the myometrium versus the rectus abdominis muscle (Student’s t-test).

Results

BLADE significantly (p < 0.0001) reduced motion and ghosting artefacts and showed improved conspicuity (p = 0.3/0.24), but overall image quality did not differ significantly (inter-observer agreement BLADE κ = 0.89; TSE κ = 0.84). In the majority of cases (53.2 % vs 59.6 %, respectively, κ = 0.82) radiologists preferred conventional TSE due to better image contrast (p < 0.0001) and visibility of free pelvic fluid (p ≤ 0.0001). SNR (TSE 57.5 ± 37.7; BLADE 16.6 ± 12.2) and CNR (TSE 40.4 ± 33.5; BLADE 7.2 ± 8.8) were significantly higher on conventional TSE (p < 0.0001).

Conclusions

Although BLADE reduces motion artefacts and provides a clearer delineation of uterine zonal anatomy compared with conventional TSE, this comes at the expense of overall contrast.

Main Messages

• Use of BLADE may reduce T2 contrast and thus visibility of free pelvic fluid or cystic structures

• Non-Cartesian sampling of k-space such as BLADE is beneficial due to less motion sensitivity

• BLADE provides clearer delineation and conspicuity of uterine zonal anatomy on pelvic MRIs