Functional MR imaging in gynecologic malignancies: current status and future perspectives

Diagnostic Value of MRI for Pelvic Lymph Node Extracapsular Invasion in Early-Stage Endometrial Carcinoma

Objective

Endometrial cancer (EC) is the major female malignant tumor in developed countries. MRI is frequently applied in gynecologic malignancies. We probed the diagnostic value of MRI for pelvic lymph node extracapsular invasion (PLNEI) in early-stage EC patients.

Methods

Totally 142 early-stage EC patients were retrospectively enrolled and divided into the PLNEInegative/PLNEIpositive groups. Differences in MRI parameters [volume index (VI), total tumor volume (TTV), tumor volume ratio (TVR), mean apparent diffusion coefficient (ADCmean)] were analyzed. Early-stage EC patients with PLNEI were categorized into the high/low VI, TTV, TVR, ADCmean groups. The relationships of VI, TTV, TVR and ADCmean with clinicopathological characteristics were analyzed. Independent influencing factors for PLNEI, and the diagnostic value of VI, TTV, TVR and ADCmean for PLNEI were analyzed by logistic univariate/multivariate regression and receiver operating characteristic curve, with differences in areas under the curves compared by Delong test.

Results

There were significant differences in the histological type, histological grade, myometrial invasion depth, LVSI positive detection, LVSI type, cervical involvement, and CA125 level between the two groups. The VI, TTV and TVR values were elevated and ADCmean value was reduced in patients with PLNEI, which were associated with the clinicopathological characteristics of early-stage EC patients. The CA125 level, VI, TTV, TVR and ADCmean were independent influencing factors for PLNEI, showing high diagnostic value for PLNEI.

Conclusion

VI, TTV, TVR, and ADCmean had high diagnostic value for PLNEI in early-stage EC patients. MRI was a good method to detect PLNEI in EC patients.

Comparison of ASL and DSC perfusion methods in the evaluation of response to treatment in patients with a history of treatment for malignant brain tumor

OBJECTIVE

Perfusion MRI is of great benefit in the post-treatment evaluation of brain tumors. Interestingly, dynamic susceptibility contrast-enhanced (DSC) perfusion has taken its place in routine examination for this purpose. The use of arterial spin labeling (ASL), a perfusion technique that does not require exogenous contrast material injection, has gained popularity in recent years. The aim of the study was to compare two different perfusion techniques, ASL and DSC, using qualitative and quantitative measurements and to investigate the diagnostic effectiveness of both. The fact that the number of patients is higher than in studies conducted with 3D pseudo-continious ASL (pCASL), the study group is heterogeneous as it consists of patients with both metastases and glial tumors, the use of 3D Turbo Gradient Spin Echo (TGSE), and the inclusion of visual (qualitative) assessment make our study unique.

METHODS

Ninety patients, who were treated for malignant brain tumor, were enrolled in the retrospective study. DSC Cerebral Blood Volume (CBV), Cerebral Blood Flow (CBF) and ASL CBF maps of each case were obtained. In qualitative analysis, the lesions of the cases were visually classified as treatment-related changes (TRC) and relapse/residual mass (RRT). In the quantitative analysis, three regions of interest (ROI) measurements were taken from each case. The average of these measurements was compared with the ROI taken from the contralateral white matter and normalized values (n) were obtained. These normalized values were compared across events.

RESULTS

Uncorrected DSC normalized CBV (nCBV), DSC normalized CBF (nCBF) and ASL nCBF values of RRT cases were higher than those of TRC cases (p < 0.001). DSC nCBV values were correlated with DSC nCBF (r: 0.94, p < 0.001) and correlated with ASL nCBF (r: 0.75, p < 0.001). Similarly, ASL nCBF was positively correlated with DSC nCBF (r: 0.79 p < 0.01). When the ROC curve parameters were evaluated, the cut-off values were determined as 1.211 for DSC nCBV (AUC: 0.95, 93% sensitivity, 82% specificity), 0.896 for DSC nCBF (AUC; 0.95, 93% sensitivity, 82% specificity), and 0.829 for ASL nCBF (AUC: 0.84, 78% sensitivity, 75% specificity). For qualitative evaluation (visual evaluation), inter-observer agreement was found to be good for ASL CBF (0.714), good for DSC CBF (0.790), and excellent for DSC CBV (0.822). Intra-observer agreement was also evaluated. For the first observer, good agreement was found in ASL CBF (0.626, 70% sensitive, 93% specific), in DSC CBF (0.713, 76% sensitive, 95% specific), and in DSC CBV (0.755, 87% sensitive - 88% specific). In the second observer, moderate agreement was found in ASL CBF (0.584, 61% sensitive, 97% specific) and DSC CBF (0.649, 65% sensitive, 100% specific), and excellent agreement in DSC CBV (0.800, 89% sensitive, 90% specific).

CONCLUSION

It was observed that uncorrected DSC nCBV, DSC nCBF and ASL nCBF values were well correlated with each other. In qualitative evaluation, inter-observer and intra-observer agreement was higher in DSC CBV than DSC CBF and ASL CBF. In addition, DSC CBV is found more sensitive, ASL CBF and DSC CBF are found more specific for both observers. From a diagnostic perspective, all three parameters DSC CBV, DSC CBF and ASL CBF can be used, but it was observed that the highest rate belonged to DSC CBV.

Diffusion-weighted magnetic resonance imaging and magnetic resonance spectroscopy for non-invasive characterization of azoospermia: A prospective comparative single-center study

BACKGROUND

Azoospermia affects about 15% of childless males. The differential diagnosis between subtypes of azoospermia is the initial step in its management.

OBJECTIVES

To investigate the role of diffusion-weighted magnetic resonance imaging and proton magnetic resonance spectroscopy in distinguishing obstructive azoospermia from non-obstructive azoospermia and predicting sperm retrieval together with histological alterations in men with non-obstructive azoospermia.

MATERIALS AND METHODS

This prospective comparative study involved 60 men with obstructive azoospermia (group A) and 60 men with non-obstructive azoospermia (group B). Scrotal proton magnetic resonance spectroscopy and diffusion-weighted magnetic resonance imaging were conducted for all participants to respectively evaluate testicular metabolites and normalized apparent diffusion coefficient 1 week before sperm retrieval.

RESULTS

Apparent diffusion coefficient was significantly higher in group B as compared to group A (0.47 ± 0.11 vs. 0.29 ± 0.05; and 0.46 ± 0.14 vs. 0.28 ± 0.02) for the right and left testis, respectively. Conversely, testicular choline and lipids were significantly higher in group A as compared to group B. Normalized apparent diffusion coefficient, choline, and lipids at cut-off levels of 0.353, 0.31, and 0.725 could differentiate between obstructive azoospermia and non-obstructive azoospermia (area under the curve = 0.963; confidence interval = 0.939-0.986, area under the curve = 0.985; confidence interval = 0.974-0.997, and area under the curve = 0.970; confidence interval = 0.940-0.999, respectively). Regarding the prediction of sperm retrieval in the non-obstructive azoospermia group, choline levels had the highest area under the curve (0.923), and its cut-off level was 0.195. The normalized apparent diffusion coefficient was significantly lower in men with positive sperm retrieval as compared to men with unsuccessful retrieval. Finally, it was revealed that all magnetic resonance imaging parameters except creatine could independently predict testicular histology in men with non-obstructive azoospermia. The highest prediction was 95% in normal spermatogenesis, and the least prediction was 40% in spermatid arrest. Regression analysis was used to detect final predictors and extrapolate an equation that could be used to predict testicular pathology CONCLUSIONS: Normalized apparent diffusion coefficient and proton magnetic resonance spectroscopy are helpful in differentiating obstructive azoospermia from non-obstructive azoospermia and predicting sperm retrieval and related histological alterations in men with non-obstructive azoospermia.

Noninvasive Differentiation of Obstructive Azoospermia and Nonobstructive Azoospermia Using Multimodel Diffusion Weighted Imaging

RATIONALE AND OBJECTIVES

To evaluate the diagnostic performance of parameters derived from multimodel diffusion weighted imaging (monoexponential, stretched-exponential diffusion weighted imaging and diffusion kurtosis imaging [DKI]) from noninvasive magnetic resonance imaging in distinguishing obstructive azoospermia (OA) from nonobstructive azoospermia (NOA).

MATERIALS AND METHODS

Forty-six patients with azoospermia were prospectively enrolled and classified into two groups (21 OA patients and 25 NOA patients). The multimodel parameters of diffusion-weighted imaging (DWI; apparent diffusion coefficient [ADC], distributed diffusion coefficient [DDC], diffusion heterogeneity [α], diffusion kurtosis diffusivity [D_app], and diffusion kurtosis coefficient [K_app]) were derived. The diagnostic performance of these parameters for the differentiation of OA and NOA patients were evaluated using receiver operating characteristic analysis. The area under the curve (AUC) was calculated to evaluate the diagnostic accuracy of each parameter.

RESULTS

All the parameters (ADC, α, DDC, D_app, and K_app) values were significantly different between OA and NOA (P < 0.001 for all). For the differentiation of OA from NOA, K_app showed the highest AUC value (0.965), followed by DDC (0.946), D_app (0.933), ADC (0.922), and α (0.887). K_app had a significantly higher AUC than the conventional ADC (P < 0.05).

CONCLUSION

Parameters derived from multimodels of DWI have the potential for the noninvasive differentiation of OA and NOA. The K_app value derived from the DKI model might serve as a useful imaging marker for the differentiation of azoospermia.

Ultrasound Features of Uterine Sarcomas

Uterine sarcomas include leiomyosarcoma, smooth muscle tumor of uncertain malignant potential, endometrial stromal sarcoma, undifferentiated sarcoma, carcinosarcoma, adenosarcoma, and rhabdomyosarcoma. Leiomyosarcomas are the most common uterine sarcomas and list some potential others. Uterine sarcomas have a wide histopathological spectrum that may display various imaging features, making the preoperative diagnosis challenging. The purpose of this review was to discuss the clinical features of uterine sarcomas, as well as their imaging appearances and characteristics. From this, practitioners can ensure that suspicious sonographic findings of uterine sarcomas, including a large-size, heterogeneous echotexture, central cystic change or necrosis, and hypervascularity, are recognized to facilitate further evaluation. Familiarity with the clinical presentations and imaging features of uterine sarcomas can lead to a more accurate diagnosis and appropriate management.

Do DWI and quantitative DCE perfusion MR have a prognostic value in high-grade serous ovarian cancer?

PURPOSE

To evaluate whether perfusion and diffusion parameters from staging MR in ovarian cancer (OC) patients may predict the presence of residual tumor at surgery and the progression-free survival (PFS) in 12 months.

MATERIALS AND METHODS

Patients who are from a single institution, candidate for OC to cytoreductive surgery and undergoing MR for staging purposes were included in this study. Inclusion criteria were: preoperative MR including diffusion-weighted imaging (DWI) and perfusion dynamic contrast-enhanced (DCE) sequence; cytoreductive surgery performed within a month from MR; and minimum follow-up of 12 months. Patients' characteristics including the presence of residual tumor at surgery (R0 or R1) and relapse within 12 months from surgery were recorded. DWI parameters included apparent diffusion coefficient (ADC) of the largest ovarian mass (O-ADC) and normalized ovarian ADC as a ratio between ovarian ADC and muscle ADC (M-ADC). DCE quantitative parameters included were descriptors of tumor vascular properties such as forward and backward transfer constants, plasma volume and volume of extracellular space. Statistical analysis was performed, and p values < 0.05 were considered significant.

RESULTS

Forty-nine patients were included. M-ADC showed a slightly significant association with the presence of residual tumor at surgery. None of the other functional parameters showed either difference between R0 and R1 patients or association with PFS in the first 12 months.

CONCLUSIONS

This preliminary study demonstrated a slightly significant association between normalized ovarian ADC and the presence of residual tumor at surgery. The other perfusion and diffusion parameters were not significant for the endpoints of this study.

Usefulness of Testicular Volume, Apparent Diffusion Coefficient, and Normalized Apparent Diffusion Coefficient in the MRI Evaluation of Infertile Men With Azoospermia

OBJECTIVE

The purpose of this article is to assess retrospectively the usefulness of testicular volume, apparent diffusion coefficient (ADC), and normalized ADC as measured using MRI in predicting the histopathologic grade of azoospermia and in differentiating obstructive from nonobstructive azoospermia.

MATERIALS AND METHODS

A computerized search generated a list of 30 infertile men with azoospermia who had undergone both scrotal MRI and testis biopsy. MRI-determined testicular volumes, ADCs, and normalized ADCs were compared between infertile men with obstructive azoospermia and those with nonobstructive azoospermia. The normalized ADC was calculated as ADC of the testis divided by the ADC of the bladder lumen.

RESULTS

Sixteen men had obstructive azoospermia and 14 had nonobstructive azoospermia. The testicular volume was significantly greater in patients with obstructive azoospermia (8.7-27.6 mL) than in patients with nonobstructive azoospermia (1.8-15.4 mL; p < 0.001). The ROC AUC for distinguishing nonobstructive from obstructive azoospermia using testicular volume was 0.92 (a cutoff value of ≤ 13.06 mL yielded sensitivity of 85.71% and specificity of 87.5%). Testicular ADC and normalized ADC were significantly lower in patients with obstructive azoospermia (0.329 × 10-3 to 1.578 × 10-3 mm2/s for ADC; 0.113 to 0.449 for normalized ADC) than in patients with nonobstructive azoospermia (0.801 × 10-3 to 2.211 × 10-3 mm2/s [p = 0.0094] for ADC; 0.235 to 0.61 [p = 0.0001] for normalized ADC). The ROC AUCs for distinguishing nonobstructive from obstructive azoospermia using testicular ADC and normalized ADC were 0.741 (a cutoff value of > 1.031 × 10-3 mm2/s yielded sensitivity of 92.86% and specificity of 56.25%) and 0.875 (a cutoff value of > 0.425 yielded sensitivity of 78.57% and specificity of 93.75%), respectively.

CONCLUSION

Testicular volume, ADC, and normalized ADC, as measured using MRI, are useful in predicting the histopathologic grade of azoospermia and in differentiating obstructive from nonobstructive azoospermia.