CT-based preoperative risk assessment of prolonged urine leak in patients undergoing partial nephrectomy.

OBJECTIVES: This study aims to evaluate risk factors of prolonged urine leak following partial nephrectomy (PN) to identify objective imaging characteristics on preoperative CT. METHODS: A total of 865 patients who underwent PN and had preoperative CT and postoperative imaging were included. We set a twofold size-matched control group without urine leak, with all tumors located ≤ 4 mm to the collecting system to identify imaging parameters that increase the risk of urine leak other than tumor size and location. Four CT parameters that show the relationship of the tumor and collecting system, namely, curvilinear border length, protruding distance, margin at the interface, and pelvicalyceal contact, were analyzed. Multivariate logistic regression analyses were performed to identify significant predictors of urine leak. The diagnostic performance of the significant parameters was evaluated using the area under the receiver operating characteristic curve (AUC). RESULTS: Fifty-three of 865 patients (6.1%) demonstrated urine leak. Compared with the control group, urine leak group showed longer curvilinear border length, longer protruding distance, frequent non-smooth contact interface, and frequent direct pelvicalyceal contact (p < 0.05 for all). In the multivariate analysis, pelvicalyceal contact was the independent predictor of urine leak (OR = 2.62; 95% C.I 1.02-6.63). Combining four CT parameters, an AUC of 0.70 with a sensitivity of 58.5% and a specificity of 79.2% for identifying urine leak after PN could be obtained. CONCLUSIONS: The four CT features that describe the relationship between the tumor and collecting system might be useful for evaluating the risk of urine leak before PN. KEY POINTS: • Four CT parameters (curvilinear border length, protruding distance, margin at the interface, and pelvicalyceal contact) were significantly associated with postoperative urine leak after partial nephrectomy. • A comprehensive preoperative imaging evaluation of the relationship between the tumor and renal sinus may help in selecting the optimal surgical options and afford better patient counseling of complication risk.

Fully automatic volume measurement of the adrenal gland on CT using deep learning to classify adrenal hyperplasia.

OBJECTIVES: To develop a fully automated deep learning model for adrenal segmentation and to evaluate its performance in classifying adrenal hyperplasia. METHODS: This retrospective study evaluated automated adrenal segmentation in 308 abdominal CT scans from 48 patients with adrenal hyperplasia and 260 patients with normal glands from 2010 to 2021 (mean age, 42 years; 156 women). The dataset was split into training, validation, and test sets at a ratio of 6:2:2. Contrast-enhanced CT images and manually drawn adrenal gland masks were used to develop a U-Net-based segmentation model. Predicted adrenal volumes were obtained by fivefold splitting of the dataset without overlapping the test set. Adrenal volumes and anthropometric parameters (height, weight, and sex) were utilized to develop an algorithm to classify adrenal hyperplasia, using multilayer perceptron, support vector classification, a random forest classifier, and a decision tree classifier. To measure the performance of the developed model, the dice coefficient and intraclass correlation coefficient (ICC) were used for segmentation, and area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, and specificity were used for classification. RESULTS: The model for segmenting adrenal glands achieved a Dice coefficient of 0.7009 for 308 cases and an ICC of 0.91 (95% CI, 0.90-0.93) for adrenal volume. The models for classifying hyperplasia had the following results: AUC, 0.98-0.99; accuracy, 0.948-0.961; sensitivity, 0.750-0.813; and specificity, 0.973-1.000. CONCLUSION: The proposed segmentation algorithm can accurately segment the adrenal glands on CT scans and may help clinicians identify possible cases of adrenal hyperplasia. KEY POINTS: • A deep learning segmentation method can accurately segment the adrenal gland, which is a small organ, on CT scans. • The machine learning algorithm to classify adrenal hyperplasia using adrenal volume and anthropometric parameters (height, weight, and sex) showed good performance. • The proposed segmentation algorithm may help clinicians identify possible cases of adrenal hyperplasia.

Prediction of acute rejection in renal allografts using shear-wave dispersion slope.

OBJECTIVES: To evaluate the role of shear-wave dispersion slope for predicting renal allograft dysfunction. METHODS: We retrospectively reviewed 128 kidney transplant recipients (median age, 55 years [interquartile range, 43-62 years]; male, 68) who underwent biopsy for allograft evaluation from November 2022 to February 2023. Cortex and renal sinus fat stiffness and shear-wave dispersion slope were obtained at shear-wave elastography (SWE). Cortex-to-sinus stiffness ratio (SR) and dispersion slope ratio (DSR)-related clinical and pathologic factors were evaluated using multivariable linear regression analysis. We conducted univariate and multivariate analyses for multiparametric ultrasound (US) parameters for identifying acute rejection and calculated the area under the receiver operating curve (AUC) values. RESULTS: Of 128 patients, 31 (24.2%) demonstrated acute rejection. The SR value did not differ between patient groups (1.21 vs. 1.20, p = 0.47). Patients with acute rejection demonstrated a higher DSR than those without rejection (1.4 vs. 1.21, p < 0.01). Interstitial fibrosis and tubular atrophy grade (IFTA; coefficient, 0.11/grade; p = 0.04) and renal transplant and biopsy interval (coefficient, 0.00007/day; p = 0.03) were SR determinant factors, whereas only IFTA grade (coefficient, 0.10/grade; p = 0.01) for DSR. Multivariate analysis revealed mean resistive index (odds ratio [OR] 1.08, 95% confidence interval [CI] 1.02-1.14, p = 0.01) and DSR value (OR 16.0, 95% CI 3.0-85.8, p = 0.001) as independent factors for predicting acute rejection. An AUC of 0.74 for detecting acute rejection was achieved by combining the resistive index and DSR value. CONCLUSION: Shear-wave dispersion slope obtained at SWE may help identify renal allograft dysfunction. CLINICAL RELEVANCE STATEMENT: Acute rejection in renal allografts is a major cause of allograft failure, but noninvasive diagnosis is a challenge. Shear-wave dispersion slope can identify acute rejection non-invasively. KEY POINTS: • The interstitial fibrosis and tubular atrophy grade was a determinant factor for stiffness ratio and shear-wave dispersion slope ratio between cortex and renal sinus fat. • Shear-wave dispersion slope ratio between cortex and renal sinus fat could identify acute rejection in renal allografts. • A shear-wave dispersion slope has a potential to reduce unnecessary renal biopsy for evaluating renal allografts.

Quantitative magnetic resonance imaging of chronic kidney disease: an experimental in vivo study using rat chronic kidney disease models.

BACKGROUND: Recent advances in magnetic resonance imaging (MRI) may allow it to be an alternative emerging tool for the non-invasive evaluation of renal parenchymal disease. PURPOSE: To validate the usefulness of quantitative multiparametric MRI protocols and suggest the suitable quantitative MR sequence protocol to evaluate parenchymal fibrosis using an animal model of chronic kidney disease (CKD) by long-term adenine intake. MATERIAL AND METHODS: In this prospective animal study, 16 male Wistar rats were analyzed and categorized into three groups. Rats in the CKD groups underwent 0.25% adenine administration for three or six weeks. Quantitative MRI protocols, including diffusion-weighted imaging (DWI), T1ρ (T1 rho), and T2* mapping were performed using a 9.4-T animal MR scanner. A semi-quantitative histopathologic analysis for renal fibrosis was conducted. Quantitative MR values measured from anatomic regions of kidneys underwent intergroup comparative analyses. RESULTS: The apparent diffusion coefficient (ADC) and T1 (T1 rho) values were significantly increased in all CKD groups. Values measured from the cortex and outer medulla showed significant intergroup differences. Total ADC values tended to increase according to periods, and T1ρ values increased in three weeks and decreased in six weeks. CONCLUSION: Quantitative MRI protocols could be a non-invasive assessment modality in the diagnosis and evaluation of CKD. Particularly, T1ρ may be a suitable MR sequence to quantitatively assess renal parenchymal fibrosis.

Prognostic implications of body composition change during primary treatment in patients with ovarian cancer: A retrospective study using an artificial intelligence-based volumetric technique.

OBJECTIVE: To investigate the impact of changes in body composition during primary treatment on survival outcomes in patients with epithelial ovarian cancer (EOC). METHODS: We retrospectively identified patients diagnosed with EOC between 2010 and 2019. Using an artificial intelligence-based tool, the volumes of skeletal muscle, visceral fat, and subcutaneous fat were measured automatically at the waist level from pre-treatment and post-treatment computed tomography scans. Associations between changes in body mass index (BMI) and volume of each body composition component and survival outcomes were evaluated. RESULTS: A total of 208 patients were included. A significant decrease in BMI and waist volumes of skeletal muscle and visceral fat was observed during the primary treatment. Patients with BMI loss ≥5% showed significantly worse progression-free survival (PFS) and overall survival (OS) than those with BMI loss <5%. In multivariate analyses adjusting for clinicopathologic factors, BMI loss ≥5% was identified as an independent poor prognostic factor for PFS (adjusted HR, 1.565; 95% CI, 1.074-2.280; P = 0.020) and OS (adjusted HR, 2.754; 95% CI, 1.382-5.488; P = 0.004). Meanwhile, both muscle loss ≥10% and visceral fat loss ≥20% were associated with an increased mortality rate but did not affect disease recurrence. In multivariate analyses, muscle loss ≥10% (adjusted HR, 2.069; 95% CI, 1.055-4.058; P = 0.034) and visceral fat loss ≥20% (adjusted HR, 2.292; 95% CI, 1.023-5.133; P = 0.044) were poor prognostic factors for OS. Consistent results were observed in the advanced-stage disease subgroup (n = 173). CONCLUSIONS: Changes in BMI and waist volume of skeletal muscle and visceral fat were associated with survival outcomes in patients with EOC.

The Efficacy of Lymph Node Embolization Using N-Butyl Cyanoacrylate Compared to Ethanol Sclerotherapy in the Management of Symptomatic Lymphorrhea after Pelvic Surgery.

PURPOSE: To compare the efficacy of lymph node (LN) embolization using N-butyl cyanoacrylate versus ethanol sclerotherapy in the management of symptomatic postoperative pelvic lymphorrhea. MATERIALS AND METHODS: Thirty-three patients with 40 instances of symptomatic postoperative lymphorrhea were treated with either LN embolization or sclerotherapy at Seoul National University Hospital from January 2009 to July 2017 and were retrospectively included (LN embolization group: 24 lymphoceles of 19 patients, mean age of 59.29 years; sclerotherapy group: 16 lymphoceles of 14 patients, mean age of 60.95 years). The types of operations were hysterectomy and bilateral oophorectomy with pelvic lymph node dissection (n = 9), radical prostatectomy (n = 3), and renal transplantation (n = 2) for the sclerotherapy group and radical prostatectomy (n = 10) and hysterectomy and bilateral oophorectomy with pelvic lymph node dissection (n = 9) for the LN embolization group. The 3 most common indications of treatment were lower extremity edema (n = 11), pain (n = 11), and fever (n = 8). The amount of leak before treatment (initial daily drainage) and clinical outcomes, including the clinical success rate in 3 weeks, treatment period, and complication rate were compared between both groups. RESULTS: LN embolization showed a higher 3-week clinical success rate than sclerotherapy in a univariate analysis (83.3% and 43.8%, P = .026). There was no statistically significant difference in the treatment period and the complication rate (7.1 days and 12.3 days, P = .098; 8.3% and 25.0%, P = .184). CONCLUSIONS: LN embolization is more effective for treating postoperative pelvic lymphorrhea than sclerotherapy with similar safety.

Pheochromocytoma as a frequent false-positive in adrenal washout CT: A systematic review and meta-analysis.

OBJECTIVE: To evaluate the proportion of pheochromocytomas meeting the criteria for adenoma on adrenal washout CT and the diagnostic performance of adrenal washout CT for differentiating adenoma from pheochromocytoma. METHODS: MEDLINE and EMBASE were searched to 28 March 2017. We included studies that used adrenal washout CT for characterisation of pheochromocytomas. Two independent reviewers assessed the methodological quality using Quality Assessment of Diagnostic Accuracy Studies-2. Proportions were pooled using an inverse variance method for calculating weights (random-effects). Sensitivity and specificity were pooled using hierarchical logistic regression modelling and plotted in a hierarchical summary receiver-operating-characteristics (HSROC) plot. RESULTS: Ten studies (114 pheochromocytomas) were included. The pooled proportion of pheochromocytomas meeting the criteria for adenomas was 35 % (95 % CI 20-51). For eight studies providing information on diagnostic performance, the pooled sensitivity and specificity for differentiating adenoma from pheochromocytoma were 0.97 (95 % CI 0.93-0.99) and 0.67 (95 % CI 0.44-0.84), respectively. The area under the HSROC curve was 0.97 (95 % CI 0.95-0.98). CONCLUSIONS: There was a non-negligible proportion of pheochromocytomas meeting the criteria for adenoma on adrenal washout CT. Although overall diagnostic performance was excellent for differentiating adenoma from pheochromocytoma, specificity was relatively low. KEY POINTS: • Non-negligible proportion of pheochromocytomas can be mistaken for adenoma. • Adrenal washout CT showed good sensitivity (97%) but relatively low specificity (67%). • Findings other than washout percentage should be used when diagnosing pheochromocytomas.

Magnetic resonance imaging for detection of parametrial invasion in cervical cancer: An updated systematic review and meta-analysis of the literature between 2012 and 2016.

OBJECTIVE: To review the diagnostic performance of MRI for detection of parametrial invasion (PMI) in cervical cancer patients. METHODS: MEDLINE and EMBASE databases were searched for studies providing diagnostic performance of MRI for detecting PMI in patients with cervical cancer. Studies published between 2012 and 2016 using surgico-pathological results as reference standard were included. Study quality was evaluated using QUADAS-2. Sensitivity and specificity of all studies were calculated. Results were pooled and plotted in a hierarchical summary receiver operating characteristic plot. Meta-regression and subgroup analyses were performed. RESULTS: Fourteen studies (1,028 patients) were included. Study quality was generally moderate. Pooled sensitivity was 0.76 (95% CI 0.67-0.84) and specificity was 0.94 (95% CI 0.91-0.95). The possibility of heterogeneity was considered low: Cochran's Q-test (p = 0.471), Tau2 (0.240), Higgins I2 (0%). With meta-regression analysis, magnet strength, use of DWI, and antispasmodic drugs were significant factors affecting heterogeneity (p < 0.01). Subgroup analysis for studies solely using radical hysterectomy as reference standard yielded pooled sensitivity and specificity of 0.73 (95% CI 0.60-0.83) and 0.93 (95% CI 0.90-0.95), respectively. CONCLUSIONS: MRI shows good performance for detection of PMI in cervical cancer. Using 3-T scanners and DWI may improve diagnostic performance. KEY POINTS: • MRI shows good performance for detection of parametrial invasion in cervical cancer. • Subgroup of studies using only radical hysterectomy showed consistent results. • Using 3-Tesla scanners and diffusion-weighted imaging may improve diagnostic performance.

The Diagnostic Performance of MRI for Detection of Lymph Node Metastasis in Bladder and Prostate Cancer: An Updated Systematic Review and Diagnostic Meta-Analysis.

OBJECTIVE: The purpose of this article is to review the diagnostic performance of MRI for the detection of pelvic lymph node (LN) metastasis in patients with bladder and prostate cancer. MATERIALS AND METHODS: MEDLINE and EMBASE were searched up to January 13, 2017. We included diagnostic accuracy studies that used MRI for pelvic LN detection in patients with bladder or prostate cancer, using histopathologic analyses published since 2000 as the reference standard. Two independent reviewers assessed the methodologic quality using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Sensitivity and specificity of all studies were calculated. Per-patient and per-LN results were pooled and plotted in a hierarchic summary ROC plot. Metaregression, sensitivity, and subgroup analyses were performed. RESULTS: Twenty-four studies (2928 patients) were included. Pooled per-patient sensitivity (n = 21) was 0.56 (95% CI, 0.42-0.69) with a specificity of 0.94 (95% CI, 0.90-0.96). Per-LN pooled estimates (n = 9) showed consistent results: sensitivity of 0.57 (95% CI, 0.29-0.82) and specificity of 0.97 (95% CI, 0.94-0.98). At metaregression analysis, type of cancer, magnet field strength, and use of ultrasmall superparamagnetic particles of iron oxide (USPIO) were significant factors affecting heterogeneity (p ≤ 0.01). Sensitivity analyses showed that specificity estimates were comparable (range, 0.87-0.95), but sensitivity estimates showed significant differences. Studies that used USPIO (n = 4) had higher sensitivity (0.86; 95% CI, 0.62-0.96) than did those not using USPIO (n = 17; 0.46; 95% CI, 0.35-0.58). CONCLUSION: MRI shows high specificity but poor and heterogeneous sensitivity for detecting pelvic LN metastasis in patients with bladder and prostate cancer. Using USPIO can improve sensitivity.

Head-To-Head Comparison Between High- and Standard-b-Value DWI for Detecting Prostate Cancer: A Systematic Review and Meta-Analysis.

OBJECTIVE: The purpose of this study was to perform a head-to-head comparison between high-b-value (> 1000 s/mm2) and standard-b-value (800-1000 s/mm2) DWI regarding diagnostic performance in the detection of prostate cancer. MATERIALS AND METHODS: The MEDLINE and EMBASE databases were searched up to April 1, 2017. The analysis included diagnostic accuracy studies in which high- and standard-b-value DWI were used for prostate cancer detection with histopathologic examination as the reference standard. Methodologic quality was assessed with the revised Quality Assessment of Diagnostic Accuracy Studies tool. Sensitivity and specificity of all studies were calculated and were pooled and plotted in a hierarchic summary ROC plot. Meta-regression and multiple-subgroup analyses were performed to compare the diagnostic performances of high- and standard-b-value DWI. RESULTS: Eleven studies (789 patients) were included. High-b-value DWI had greater pooled sensitivity (0.80 [95% CI, 0.70-0.87]) (p = 0.03) and specificity (0.92 [95% CI, 0.87-0.95]) (p = 0.01) than standard-b-value DWI (sensitivity, 0.78 [95% CI, 0.66-0.86]); specificity, 0.87 [95% CI, 0.77-0.93] (p < 0.01). Multiple-subgroup analyses showed that specificity was consistently higher for high- than for standard-b-value DWI (p ≤ 0.05). Sensitivity was significantly higher for high- than for standard-b-value DWI only in the following subgroups: peripheral zone only, transition zone only, multiparametric protocol (DWI and T2-weighted imaging), visual assessment of DW images, and per-lesion analysis (p ≤ 0.04). CONCLUSION: In a head-to-head comparison, high-b-value DWI had significantly better sensitivity and specificity for detection of prostate cancer than did standard-b-value DWI. Multiple-subgroup analyses showed that specificity was consistently superior for high-b-value DWI.

Head-to-Head Comparison Between Biparametric and Multiparametric MRI for the Diagnosis of Prostate Cancer: A Systematic Review and Meta-Analysis.

OBJECTIVE: The purpose of this study was to perform a systematic review and meta-analysis of a head-to-head comparison between the performance of biparametric MRI (bpMRI; only T2-weighted imaging and DWI) and that of multiparametric MRI (mpMRI; T2-weighted imaging, DWI, dynamic contrast-enhanced MRI) for the diagnosis of prostate cancer. MATERIALS AND METHODS: The PubMed and Embase databases were searched up to November 11, 2017. The search included diagnostic test accuracy studies that compared bpMRI and mpMRI for prostate cancer diagnosis with histopathologic findings from biopsy or radical prostatectomy as the reference standard. Methodologic quality was evaluated with the revised Quality Assessment of Diagnostic Accuracy Studies tool. Sensitivity and specificity were pooled by means of bivariate and hierarchic summary ROC (HSROC) modeling and graphically presented with HSROC plots. Meta-regression analysis and multiple subgroup analyses were used to compare the diagnostic performances of bpMRI and mpMRI. RESULTS: Twenty studies (2142 patients) were included. Pooled sensitivity and specificity were 0.74 (95% CI, 0.66-0.81) and 0.90 (95% CI, 0.86-0.93) for bpMRI and 0.76 (95% CI, 0.69-0.82) and 0.89 (95% CI, 0.85-0.93) for mpMRI. MRI protocol (bpMRI vs mpMRI) was not a significant factor in heterogeneity (p = 0.83). In 26 subgroups evaluated on the basis of stratification to clinicopathologic, study, and MRI characteristics, MRI protocol (bpMRI vs mpMRI) was not a significant factor in heterogeneity in any subgroup (p = 0.25-0.97). CONCLUSION: A head-to-head comparison showed that the performance of bpMRI was similar to that of mpMRI in the diagnosis of prostate cancer. Consistent results were found in multiple subgroup analyses.

Differentiation between papillary renal cell carcinoma and fat-poor angiomyolipoma: a preliminary study assessing detection of intratumoral hemorrhage with chemical shift MRI and T2*-weighted gradient echo.

Background Recent literature suggests that intratumoral hemorrhage detection may be helpful in differentiating papillary renal cell carcinoma (pRCC) from fat-poor angiomyolipoma (fpAML). Purpose To determine whether intratumoral hemorrhage detected using chemical shift magnetic resonance imaging (MRI) and T2*-weighted (T2*W) gradient echo (GRE) can be used to differentiate pRCC from fpAML. Material and Methods This retrospective study included 42 patients with pRCC (n = 28) and fpAML (n = 14) who underwent MRI followed by surgery. Two blinded radiologists independently assessed the presence of intratumoral hemorrhage using chemical shift MRI (decrease in signal intensity from opposed- to in-phase) and T2*W GRE ("blooming"). Consensus reading was determined for discrepant cases. MRI findings were compared using Chi-square test. Inter-observer agreement was assessed using kappa statistics. Results Inter-observer agreement was substantial for both sequences ( k = 0.622 and 0.793, P < 0.001). For chemical shift MRI, the prevalence of intratumoral hemorrhage was significantly greater in pRCC than in fpAML (71.4% versus 28.6%, P = 0.019 for reader 1; 64.3% versus 14.3%, P = 0.003 for reader 2; and 75% versus 21.4%, P = 0.002 for the consensus). T2*W GRE showed a similar tendency (46.4% versus 14.3%, P = 0.049 for both readers; and 50% versus 14.3%, P = 0.042 for the consensus). Using the consensus reading, sensitivity and specificity of determining pRCC were 75% and 78.6% for chemical shift MRI and 50% and 85.7% for T2*W GRE. Conclusion The prevalence of intratumoral hemorrhage identified from chemical shift MRI or T2*W GRE was significantly different between pRCC and fpAML. These hemorrhage-sensitive MRI sequences may be used as an adjunctive tool for discriminating between the two entities.

Apparent diffusion coefficient for prediction of parametrial invasion in cervical cancer: a critical evaluation based on stratification to a Likert scale using T2-weighted imaging.

PURPOSE: To evaluate the value of apparent diffusion coefficient (ADC) for determining parametrial invasion (PMI) in cervical cancer, by stratifying them into subgroups based on a Likert scale using T2-weighted imaging (T2WI). MATERIALS AND METHODS: This retrospective study included 87 patients with FIGO stage IA2-IIB cervical cancer who underwent preoperative MRI followed by radical hysterectomy. Radiological PMI was assessed on T2WI using a six-point Likert scale and ADC values of the tumors were measured. MRI findings were compared between patients with and without PMI. Differences in ADC according to the Likert scale were also assessed. RESULTS: 19 (21.8%) patients had pathological PMI. The prevalence of PMI was significantly associated with Likert scale (P < 0.001). ADC values significantly differed according to Likert scale (P < 0.001). However, only tumors with a Likert score of 0 (MRI-invisible) had significantly greater ADC than others (P < 0.001) while no significant difference was observed among tumors with Likert scores of 1-5 (P = 0.070-0.889). Patients with PMI had significantly lower ADC values than those without PMI (P = 0.034). However, no significant difference was seen between patients with and without PMI within each Likert score group (P = 0.180-0.857). CONCLUSION: T2WI-based Likert score for radiological PMI and ADC values of the tumor were significantly associated with pathological PMI. However, the apparent association seen between ADC values and PMI may be due to contribution of high ADC values of MRI-invisible tumors rather than reflecting their relationship.

Diagnostic value of integrated PET/MRI for detection and localization of prostate cancer: Comparative study of multiparametric MRI and PET/CT.

PURPOSE: To evaluate the diagnostic value of integrated positron emission tomography/magnetic resonance imaging (PET/MRI) compared with conventional multiparametric MRI and PET/computed tomography (CT) for the detailed and accurate segmental detection/localization of prostate cancer. MATERIALS AND METHODS: Thirty-one patients who underwent integrated PET/MRI using 18 F-choline and 18 F-FDG with an integrated PET/MRI scanner followed by radical prostatectomy were included. The prostate was divided into six segments (sextants) according to anatomical landmarks. Three radiologists noted the presence and location of cancer in each sextant on four different image interpretation modalities in consensus (1, multiparametric MRI; 2, integrated 18 F-FDG PET/MRI; 3, integrated 18 F-choline PET/MRI; and 4, combined interpretation of 1 and 18 F-FDG PET/CT). Sensitivity, specificity, accuracy, positive and negative predictive values, likelihood ratios, and diagnostic performance based on the DOR (diagnostic odds ratio) and NNM (number needed to misdiagnose) were evaluated for each interpretation modality, using the pathologic result as the reference standard. Detection rates of seminal vesicle invasion and extracapsular invasion were also evaluated. RESULTS: Integrated 18 F-choline PET/MRI showed significantly higher sensitivity than did multiparametric MRI alone in high Gleason score patients (77.0% and 66.2%, P = 0.011), low Gleason score patients (66.7% and 47.4%, P = 0.007), and total patients (72.5% and 58.0%, P = 0.008) groups. Integrated 18 F-choline PET/MRI and 18 F-FDG PET/MRI showed similar sensitivity and specificity to combined interpretation of multiparametric MRI and 18 F-FDG PET/CT (for sensitivity, 58.0%, 63.4%, 72.5%, and 68.7%, respectively, and for specificity, 87.3%, 80.0%, 81.8%, 72.7%, respectively, in total patient group). However, integrated 18 F-choline PET/MRI showed the best diagnostic performance (as DOR, 11.875 in total patients, 27.941 in high Gleason score patients, 5.714 in low Gleason score groups) among the imaging modalities, regardless of Gleason score. Integrated 18 F-choline PET/MRI showed higher sensitivity and diagnostic performance than did integrated 18 F-FDG PET/MRI (as DOR, 6.917 in total patients, 15.143 in high Gleason score patients, 3.175 in low Gleason score groups) in all three patient groups. CONCLUSION: Integrated PET/MRI carried out using a dedicated integrated PET/MRI scanner provides better sensitivity, accuracy, and diagnostic value for detection/localization of prostate cancer compared to multiparametric MRI. Generally, integrated 18 F-choline PET/MRI shows better sensitivity, accuracy, and diagnostic performance than does integrated 18 F-FDG PET/MRI as well as combined interpretation of multiparametric MRI with 18 F-FDG PET/CT. LEVEL OF EVIDENCE: 2 J. Magn. Reson. Imaging 2017;45:597-609.

Assessment of deep myometrial invasion of endometrial cancer on MRI: added value of second-opinion interpretations by radiologists subspecialized in gynaecologic oncology.

OBJECTIVE: To investigate the added value of secondary reports issued by radiologists subspecializing in gynaecologic imaging for determining deep myometrial invasion of endometrial cancer on MRI. METHODS: Initial (from referring institutions) and secondary (by subspecialized radiologists) interpretations of MRI of 55 patients with endometrial cancer were retrospectively reviewed. A radiologist blinded to clinicopathological information assessed both reports for the presence of deep myometrial invasion. Reference standard was based on hysterectomy specimens. Kappa coefficients (k) were used to measure their concordance. McNemar testing and receiver operating characteristic (ROC) analysis was used to compare sensitivities, specificities and areas under the curves (AUCs). RESULTS: Deep myometrial invasion was present in 25 (45.5 %) patients. Among 27.3 % (15/55; k = 0.458) patients with discrepant results, secondary interpretations were correct in 10 (66.7 %) cases. Sensitivity was higher in secondary than in initial reports (76.0 % vs. 48.0 %, p = 0.039) while no significant difference was seen in specificity (70.0 % vs. 76.7 %, p = 0.668). At ROC analysis, there was a tendency for higher AUCs in secondary reports (0.785 vs 0.669, p = 0.096). CONCLUSION: Secondary readings of MRI by subspecialized gynaecologic oncologic radiologists may provide incremental value in determining deep myometrial invasion of endometrial cancer. KEY POINTS: • Deep myometrial invasion is an important prognostic factor in endometrial cancer. • Assessment of deep myometrial invasion is often discrepant between initial and secondary reports. • Secondary reports showed higher sensitivity and accuracy. • Secondary review of MRI may provide incremental value in endometrial cancer patients.

Shear-Wave Elastography for Detection of Prostate Cancer: A Systematic Review and Diagnostic Meta-Analysis.

OBJECTIVE: The objective of this study is to review the diagnostic performance of shear-wave elastography (SWE) in the detection of prostate cancer (PCa). MATERIALS AND METHODS: The MEDLINE, EMBASE, and Cochrane library databases were searched up to December 23, 2016. We included diagnostic accuracy studies that used SWE for PCa detection with prostatectomy or biopsy used as the reference standard. The methodologic quality of the studies was evaluated by two independent reviewers using the revised Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. The sensitivity and specificity of all studies were calculated. Results were pooled and plotted in a hierarchical summary ROC plot with further exploration done using meta-regression analysis and subgroup analysis. RESULTS: Eight studies (a total of 1028 patients) were evaluated. The pooled sensitivity was 0.83 (95% CI, 0.66-0.92) with a specificity of 0.85 (95% CI, 0.78-0.90) for the detection of PCa. Study design (prospective vs retrospective) was the only significant factor affecting heterogeneity (p < 0.01). At subgroup analysis, the pooled sensitivity and specificity were 0.84 (95% CI, 0.64-0.94) and 0.84 (95% CI, 0.76-0.90), respectively, in studies using shear-wave speed imaging and 0.84 (95% CI, 0.64-0.94) and 0.86 (95% CI, 0.78-0.91), respectively, in studies based on per-lesion analysis. CONCLUSION: SWE shows good performance for the detection of PCa. However, specific recommendations regarding cutoff value cannot be made because of study heterogeneity.

Diagnostic Performance of CT for Diagnosis of Fat-Poor Angiomyolipoma in Patients With Renal Masses: A Systematic Review and Meta-Analysis.

OBJECTIVE: The purpose of this article is to systematically review and perform a meta-analysis of the diagnostic performance of CT for diagnosis of fat-poor angiomyolipoma (AML) in patients with renal masses. MATERIALS AND METHODS: MEDLINE and EMBASE were systematically searched up to February 2, 2017. We included diagnostic accuracy studies that used CT for diagnosis of fat-poor AML in patients with renal masses, using pathologic examination as the reference standard. Two independent reviewers assessed the methodologic quality using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Sensitivity and specificity of included studies were calculated and were pooled and plotted in a hierarchic summary ROC plot. Sensitivity analyses using several clinically relevant covariates were performed to explore heterogeneity. RESULTS: Fifteen studies (2258 patients) were included. Pooled sensitivity and specificity were 0.67 (95% CI, 0.48-0.81) and 0.97 (95% CI, 0.89-0.99), respectively. Substantial and considerable heterogeneity was present with regard to sensitivity and specificity (I2 = 91.21% and 78.53%, respectively). At sensitivity analyses, the specificity estimates were comparable and consistently high across all subgroups (0.93-1.00), but sensitivity estimates showed significant variation (0.14-0.82). Studies using pixel distribution analysis (n = 3) showed substantially lower sensitivity estimates (0.14; 95% CI, 0.04-0.40) compared with the remaining 12 studies (0.81; 95% CI, 0.76-0.85). CONCLUSION: CT shows moderate sensitivity and excellent specificity for diagnosis of fat-poor AML in patients with renal masses. When methods other than pixel distribution analysis are used, better sensitivity can be achieved.

Diagnostic Performance of DWI for Differentiating High- From Low-Grade Clear Cell Renal Cell Carcinoma: A Systematic Review and Meta-Analysis.

OBJECTIVE: The purpose of our study was to review the diagnostic performance of DWI for differentiating high- from low-grade clear cell renal cell carcinoma (RCC). MATERIALS AND METHODS: MEDLINE, EMBASE, and Cochrane library databases were searched up to March 15, 2017. We included diagnostic accuracy studies that used DWI for differentiating high- from low-grade clear cell RCC compared with histopathologic results of Fuhrman grade based on nephrectomy or biopsy specimens in original research articles. Two independent reviewers assessed methodologic quality using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Sensitivity and specificity of the included studies were pooled and graphically presented using a hierarchic summary ROC plot. For heterogeneity exploration, we assessed the presence of a threshold effect and performed meta-regression analyses. RESULTS: Eight retrospective studies (394 patients with 397 clear cell RCCs) were included. Pooled sensitivity was 0.78 (95% CI, 0.68-0.85) with a specificity of 0.86 (95% CI, 0.70-0.94). A considerable threshold effect was observed with a correlation coefficient of 0.811 (95% CI, 0.248-0.964) between the sensitivity and false-positive rate. At meta-regression analysis, apparent diffusion coefficient (× 10 mm2/s) cutoff value (< 1.57 vs ≥ 1.57; p = 0.03) and location of ROI (solid portion vs whole tumor; p = 0.04) were significant factors affecting heterogeneity. Other factors with regard to patients and tumors, study, and MRI characteristics were not significant (p = 0.17-0.91). CONCLUSION: DWI shows moderate diagnostic performance for differentiating high-from low-grade clear cell RCC. Substantial heterogeneity was observed because of a threshold effect. Further prospective studies may be needed; all included studies were retrospective.

Clear Cell Adenocarcinoma of the Urethra in Women: Distinctive MRI Findings for Differentiation From Nonadenocarcinoma and Non-Clear Cell Adenocarcinoma of the Urethra.

OBJECTIVE: The purpose of this study is to evaluate the MRI findings differentiating clear cell adenocarcinoma of the urethra (CCAU) from nonadenocarcinoma of the urethra (NACU) and non-clear cell adenocarcinoma of the urethra (NCCAU) in women. MATERIALS AND METHODS: Six women with pathologically proven CCAU, six women with pathologically confirmed NACU (two squamous cell carcinomas and four transitional cell carcinomas), and nine women with NCCAU underwent preoperative MRI. The MRI findings for CCAU, NACU, and NCCAU were reviewed by a radiologist who was blinded to the histopathologic findings and were compared using the Mann-Whitney U test and the Fisher exact test. RESULTS: CCAU was shorter in height than NACU (3.4 cm vs 5.5 cm; p = 0.020) and also had a smaller height-to-width ratio than NACU (0.85 vs 1.51; p < 0.001) and NCCAU (0.85 vs 1.48; p = 0.002). The proportion of preserved urethra in CCAU (67%) was larger than that in either NACU (9%; p < 0.001) or NCCAU (22%; p < 0.001). All cases of CCAU originated within a diverticulum, whereas none of the cases of NACU and only one NCCAU originated in a diverticulum. Intratumoral septation was more frequently observed in CCAU (100%) than in NACU (16.6%; p = 0.015) or NCCAU (11.1%; p = 0.001). CONCLUSION: MRI findings for CCAU were significantly distinctive, compared with findings for NACU and NCCAU. All cases of CCAU were associated with a urethral diverticulum, and CCAU had a lower height-to-width ratio, more frequent intratumoral septation, and greater preservation of normal urethra than did NACU and NCCAU.

Total kidney and liver volume is a major risk factor for malnutrition in ambulatory patients with autosomal dominant polycystic kidney disease.

BACKGROUND: In patients with autosomal dominant polycystic kidney disease (ADPKD), malnutrition may develop as renal function declines and the abdominal organs become enlarged. We investigated the relationship of intra-abdominal mass with nutritional status. METHODS: This cross-sectional study was performed at a tertiary hospital outpatient clinic. Anthropometric and laboratory data including serum creatinine, albumin, and cholesterol were collected, and kidney and liver volumes were measured. Total kidney and liver volume was defined as the sum of the kidney and liver volumes and adjusted by height (htTKLV). Nutritional status was evaluated by using modified subjective global assessment (SGA). RESULTS: In a total of 288 patients (47.9% female), the mean age was 48.3 ± 12.2 years and the mean estimated glomerular filtration rate (eGFR) was 65.3 ± 25.3 mL/min/1.73 m2. Of these patients, 21 (7.3%) were mildly to moderately malnourished (SGA score of 4 and 5) and 63 (21.7%) were at risk of malnutrition (SGA score of 6). Overall, patients with or at risk of malnutrition were older, had a lower body mass index, lower hemoglobin levels, and poorer renal function compared to the well-nourished group. However, statistically significant differences in these parameters were not observed in female patients, except for eGFR. In contrast, a higher htTKLV correlated with a lower SGA score, even in subjects with an eGFR ≥45 mL/min/1.73 m2. Subjects with an htTKLV ≥2340 mL/m showed an 8.7-fold higher risk of malnutrition, after adjusting for age, hemoglobin, and eGFR. CONCLUSIONS: Nutritional risk was detected in 30% of ambulatory ADPKD patients with relatively good renal function. Intra-abdominal organomegaly was related to nutritional status independently from renal function deterioration.