CT Evaluation of the Findings of Nutcracker Syndrome in Patients with Bladder Cancer after Radical Cystectomy and Ileal Neobladder Formation: A Correlation with Hematuria.

Purpose: Patients with bladder cancer may show hematuria after radical cystectomy with ileal neobladder formation, causing anxiety regarding tumor recurrence. Here, we aim to show that the nutcracker syndrome (NCS) can be a cause of hematuria post-operation, and is a common, rather than a rare syndrome. Materials and Methods: A retrospective review of contrast-enhanced abdominopelvic CT (CE-APCT) and urine analysis (UA) findings of 255 patients with bladder cancer who underwent radical cystectomy and ileal neobladder formation between 2011 and 2016 was performed. In the CE-APCT review, the left renal vein flow patterns were evaluated to determine the presence of NCS findings. In the UA review, patients were classified according to the percentage of UA tests with positive hematuria among the total number of UA tests. Results: CT findings of NCS were present in 31.9% of the 135 patients. In the positive hematuria group, there were 26% more patients with NCS findings than those without. Conclusion: NCS findings are prevalent even for bladder cancer patients after surgery, and there is a strong correlation between NCS findings and hematuria. Furthermore, the prevalence of NCS findings is much higher than urinary tract recurrence after the surgery.

Prediction of Pathologic Findings with MRI-Based Clinical Staging Using the Bayesian Network Modeling in Prostate Cancer: A Radiation Oncologist Perspective.

PURPOSE: This study aimed to develop a model for predicting pathologic extracapsular extension (ECE) and seminal vesicle invasion (SVI) while integrating magnetic resonance imaging-based T-staging (cTMRI, cT1c-cT3b). MATERIALS AND METHODS: A total of 1,915 who underwent radical prostatectomy between 2006-2016 met the inclusion/exclusion criteria. We performed a multivariate logistic regression analysis as well as Bayesian network (BN) modeling based on possible confounding factors. The BN model was internally validated using 5-fold validation. RESULTS: According to the multivariate logistic regression analysis, initial prostate-specific antigen (iPSA) (ß=0.050, p < 0.001), percentage of positive biopsy cores (PPC) (ß=0.033, p < 0.001), both lobe involvement on biopsy (ß=0.359, p=0.009), Gleason score (ß=0.358, p < 0.001), and cTMRI (ß=0.259, p < 0.001) were significant factors for ECE. For SVI, iPSA (ß=0.037, p < 0.001), PPC (ß=0.024, p < 0.001), Gleason score (ß=0.753, p < 0.001), and cTMRI (ß=0.507, p < 0.001) showed statistical significance. BN models to predict ECE and SVI were also successfully established. The overall area under the receiver operating characteristic curve (AUC)/accuracy of the BN models were 0.76/73.0% and 0.88/89.6% for ECE and SVI, respectively. According to internal comparison between the BN model and Roach formula, BN model had improved AUC values for predicting ECE (0.76 vs. 0.74, p=0.060) and SVI (0.88 vs. 0.84, p < 0.001). CONCLUSION: Two models to predict pathologic ECE and SVI integrating cTMRI were established and installed on a separate website for public access to guide radiation oncologists.

Utilization of virtual low-keV monoenergetic images generated using dual-layer spectral detector computed tomography for the assessment of peritoneal seeding from ovarian cancer.

This study aimed to compare the quality of virtual low-keV monoenergetic images vs conventional images reconstructed from dual-layer spectral detector computed tomography (SDCT) for the detection of peritoneal implants of ovarian cancer.Fifty ovarian cancer patients who underwent abdominopelvic SDCT scans were included in this retrospective study. Virtual monoenergetic images at 40 (VMI40) and 50 keV (VMI50), and two conventional images were reconstructed using filtered back projection (FBP) and iterative model reconstruction (IMR) protocols. The mean attenuation of the peritoneal implant, signal-to-noise ratio (SNR), contrast-to-noise ratio relative to ascites (CNRA) and adjacent reference tissues (e.g., bowel wall, hepatic, or splenic parenchyma [CNRB]) were calculated and compared using paired t tests. Qualitative image analysis regarding overall image quality, image noise, image blurring, lesion conspicuity, was performed by two radiologists. A subgroup analysis according to the peritoneal implant region was also conducted.VMI40 yielded significantly higher mean attenuation (183.35) of SNR and CNR values (SNR 11.69, CNRA 7.39, CNRB 2.68), compared to VMI50, IR, and FBP images (P < .001). The mean attenuation (129.65), SNR and CNR values (SNR 9.37, CNRA 5.72, CNRB 2.02) of VMI50 were also significantly higher than those of IR and FBP images (P < .001). In the subgroup analysis, all values were significantly higher on VMI40 regardless of the peritoneal implant region (P < .05). In both readers, overall image quality and image blurring showed highest score in VMI50, while image noise and lesion conspicuity showed best score in IMR and VMI40 respectively. Inter-reader agreements are moderate to almost perfect in every parameter.The low-keV VMIs improved both quantitative assessment and lesion conspicuity of peritoneal implants from ovarian cancer compared to conventional images.

Consensus survey on pre-procedural safety practices in radiological examinations: a multicenter study in seven Asian regions.

OBJECTIVE: To understand the status of pre-procedural safety practices in radiological examinations at radiology residency training institutions in various Asian regions. METHODS: A questionnaire based on the Joint Commission International Accreditation Standards was electronically sent to 3 institutions each in 10 geographical regions across 9 Asian countries. Questions addressing 45 practices were divided into 3 categories. A five-tier scale with numerical scores was used to evaluate safety practices in each institution. Responses obtained from three institutions in the United States were used to validate the execution rate of each surveyed safety practice. RESULTS: The institutional response rate was 70.0% (7 Asian regions, 21 institutions). 44 practices (all those surveyed except for the application of wrist tags for identifying patients with fall risks) were validated using the US participants. Overall, the Asian participants reached a consensus on 89% of the safety practices. Comparatively, most Asian participants did not routinely perform three pre-procedural practices in the examination appropriateness topic. CONCLUSION: Based on the responses from 21 participating Asian institutions, most routinely perform standard practices during radiological examinations except when it comes to examination appropriateness. This study can provide direction for safety policymakers scrutinizing and improving regional standards of care. ADVANCES IN KNOWLEDGE: This is the first multicenter survey study to elucidate pre-procedural safety practices in radiological examinations in seven Asian regions.

History of the Asian Society of Abdominal Radiology.

The history and administrative system of the Asian Society of Abdominal Radiology (ASAR) are described briefly with a focus on its academic activity, including congresses and education. ASAR is one of the three regional societies in the field of abdominal radiology, comprising approximately 2500 members from seven countries in Asia. A further increase in the numbers of members and affiliated societies is expected with the advancement of imaging technology and the distribution of radiologic equipment and knowledge. ASAR is responsible in Asia for matters of interdisciplinary collaboration in the field of abdominal radiology and has successfully represented Asia in the field of radiology.

Doppler US and CT Diagnosis of Nutcracker Syndrome.

Nutcracker syndrome (NCS) is a syndrome caused by compression of the left renal vein (LRV), between the abdominal aorta and the superior mesenteric artery, resulting in hypertension of the LRV and hematuria. Doppler ultrasonography (US) has been commonly used for the diagnosis of NCS. However, several technical issues, such as Doppler angle and sample volume, need to be considered to obtain satisfactory results. In addition, morphologic changes of the LRV and a jetting phenomenon across the aortomesenteric portion of the LRV on contrast-enhanced computed tomography (CECT) are diagnostic clues of NCS. With proper Doppler US and CECT, NCS can be diagnosed noninvasively.

Establishment of the Seoul National University Prospectively Enrolled Registry for Genitourinary Cancer (SUPER-GUC): A prospective, multidisciplinary, bio-bank linked cohort and research platform.

Purpose: To establish a prospective, comprehensive, multidisciplinary, bio-bank linked genitourinary cancer cohort based on standard real practice. Materials and Methods: We established the Seoul National University Prospectively Enrolled Registry for Genitourinary Cancer (SUPER-GUC), a prospective cohort clinical database and bio-specimen repository system for prostate cancer (SUPER-PC), renal cell carcinoma (SUPER-RCC), and urothelial cancer (SUPER-UC) at a high-volume, tertiary institution. Each cohort consists of several sub-cohorts based on treatment or disease status. Detailed longitudinal clinical information, and general and disease specific patient-reported outcomes are captured. We use the same evaluation format and questionnaires for all participating departments. Patients' blood, urine, tumor, and normal tissues are collected. The number of registered patients and their basic characteristics are summarized. For the surgical sub-cohort, study participation, bio-specimen, and tissue banking rates are analyzed. Results: Since March 2016, 11 sub-cohorts for all disease statuses have been opened, ranging from low-risk localized to metastatic disease. SUPER-PC, SUPER-RCC, and SUPER-UC enrolled 929, 796, and 1,221 patients, respectively. Study participation, bio-sampling, and fresh frozen tumor banking rates of surgical sub-cohorts were 89.0% to 93.1%, 91.2% to 99.1%, and 56.9% to 79.1%, respectively. Conclusions: SUPER-GUC is a study platform for comparative outcome, quality-of-life, and translational (genetics, biomarkers) research for genitourinary cancer.

Diagnostic Performance of MRI for Assessing Parametrial Invasion in Cervical Cancer: A Head-to-Head Comparison between Oblique and True Axial T2-Weighted Images.

OBJECTIVE: To directly compare the diagnostic performance of true and oblique axial T2-weighted imaging (T2WI) for assessing parametrial invasion (PMI) in cervical cancer. MATERIALS AND METHODS: This retrospective study included 71 women with treatment-naive cervical cancer who underwent MRI that included both oblique and true axial T2WI, followed by radical hysterectomy. Two blinded radiologists (Radiologist 1 and Radiologist 2) independently assessed the presence of PMI on both sequences using a 5-point Likert scale. Receiver operating characteristic (ROC) curve analysis was performed, with a subgroup analysis for tumors sized > 2.5 cm and ≤ 2.5 cm in diameter. Inter-reader agreement was assessed with kappa (k) statistics. RESULTS: At hysterectomy, 15 patients (21.1%) had PMI. For Radiologist 1, the area under the ROC curve (AUC) was greater for oblique axial than for true axial T2WI {0.941 (95% confidence interval [CI] = 0.858-0.983) vs. 0.917 (95% CI = 0.827-0.969), p = 0.027}. The difference was not significant for Radiologist 2 (0.879 [95% CI = 0.779-0.944] vs. 0.827 [95% CI = 0.719-0.906], p = 0.153). For tumors > 2.5 cm, AUC was greater with oblique than with true axial T2WI (0.906 vs. 0.860, p = 0.046 for Radiologist 1 and 0.839 vs. 0.765, p = 0.086 for Radiologist 2). Agreement between the radiologists was almost perfect for oblique axial T2WI (k = 0.810) and was substantial for true axial T2WI (k = 0.704). CONCLUSION: Oblique axial T2WI potentially provides greater diagnostic performance than true axial T2WI for determining PMI, particularly for tumors > 2.5 cm. The inter-reader agreement was greater with oblique axial T2WI.

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.

Intravoxel incoherent motion MRI-derived parameters and T2* relaxation time for noninvasive assessment of renal fibrosis: An experimental study in a rabbit model of unilateral ureter obstruction.

PURPOSE: To evaluate the association of apparent diffusion coefficient (ADC), intravoxel incoherent motion (IVIM) MRI-derived parameters, and T2* relaxation time with histopathological changes observed during renal fibrogenesis in a rabbit model of unilateral ureter obstruction (UUO). METHODS: Twenty New Zealand White rabbits underwent baseline MRI followed by surgery (sham or UUO) and then follow-up MRI at postoperative day (POD) 0, 3, 7, and 14. Hematoxylin and eosin and Masson's trichrome staining was performed to evaluate cell density and area of fibrosis. Spearman rank correlation and Pearson correlation tests and one-way analysis of variance were used for statistical analyses. RESULTS: There was a continuous increase in the area of fibrosis and cell density: rho = 0.900 (95% confidence interval [CI] = 0.760, 0.960; p < 0.0001) and 0.904 (95% CI = 0.769, 0.962; p < 0.0001), respectively. There was a tendency for all MRI variables to decrease at POD 3 and partly recover at POD 7. ADC, D, f, and T2* relaxation time showed significant correlation with area of fibrosis and cell density (r = -0.5177 and -0.6962, -0.5395 and -0.7851, -0.7168 and -0.7902, and -0.6808 and -0.7212, respectively; p = 0.0052-0.0481) while D* did not (p = 0.1997 and 0.7853, respectively). CONCLUSIONS: ADC, IVIM MRI-derived parameters, and T2* relaxation time were significantly associated with the area of fibrosis and cell density during renal fibrogenesis in a rabbit model of UUO. After validation in future studies, MRI may have potential for noninvasive assessment modality of renal fibrosis.

What MRI features suspect malignant pure mesenchymal uterine tumors rather than uterine leiomyoma with cystic degeneration?

OBJECTIVE: To retrospectively assess conventional magnetic resonance imaging (MRI) features that differentiate malignant pure mesenchymal uterine tumors (MPMUT); endometrial stromal sarcoma (ESS) and leiomyosarcoma (LMS) from uterine leiomyoma with cystic degeneration (ULCD). METHODS: We retrospectively reviewed magnetic resonance (MR) images of 30 patients with ULCD, 18 with ESS, and 15 with LMS, to assess tumor location, margin, T2 signal intensity (SI), speckled appearance, and peripheral band using univariate and multivariate analyses. RESULTS: ULCD more frequently showed subserosal location (53.3%), well-defined margin (96.7%), and speckled appearance (90.0%) compared with ESS (0%, 33.3%, and 33.3%, respectively) or LMS (20.0%, 33.3%, and 60.0%, respectively). In quantitative T2 SI comparisons, the T2 SI ratio of the main solid tumor portion to gluteus maximus muscle differed significantly among the three groups, with ULCD showing a lower SI ratio (0.62) compared with ESS (2.44) and LMS (1.13). On multivariate analysis, an ill-defined margin (odds ratio [OR]=44.885; p=0.003) and high T2 SI (OR=4.396; p=0.046) were the significant MR differentiators. CONCLUSION: An ill-defined tumor margin and high T2 SI ratio of the main solid tumor-to-gluteus maximus muscle were useful MRI features in the differentiation of MPMUT from ULCD.

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.

Diagnostic Performance of Magnetic Resonance Imaging for the Detection of Bone Metastasis in Prostate Cancer: A Systematic Review and Meta-analysis.

CONTEXT: Magnetic resonance imaging (MRI) has been tested for detecting bone metastasis and has shown promising results. Yet, consensus has not been reached regarding whether it can replace the role of bone scintigraphy in this clinical setting or not. OBJECTIVE: To review the diagnostic performance of contemporary (≥1.5 T) MRI for the detection of bone metastasis in patients with prostate cancer. EVIDENCE ACQUISITION: MEDLINE and EMBASE were searched up to January 22, 2017. We included studies that used MRI using ≥1.5-T scanners for the detection of bone metastasis in patients with prostate cancer, using histopathology or best value comparator as the reference standard. Two independent reviewers assessed the methodological quality using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Per-patient sensitivity and specificity of included studies were calculated, and pooled and plotted in a hierarchical summary receiver operating characteristic plot. Meta-regression and sensitivity analyses were performed. EVIDENCE SYNTHESIS: Ten studies (1031 patients) were included. Pooled sensitivity was 0.96 (95% confidence interval [CI] 0.87-0.99) with a specificity of 0.98 (95% CI 0.93-0.99). At meta-regression analysis, only the number of imaging planes (≥2 vs 1) was a significant factor affecting heterogeneity (p<0.01). Sensitivity analyses showed that specificity estimates were comparable and consistently high across all subgroups, but sensitivity estimates demonstrated some differences. Studies using two or more planes (n=4) had the highest sensitivity (0.99 [95% CI 0.98-1.00]). CONCLUSIONS: Contemporary MRI shows excellent sensitivity and specificity for detection of bone metastasis in patients with prostate cancer. Using two or more imaging planes may further improve sensitivity. However, caution is needed in applying our results due to the heterogeneity among the included studies. PATIENT SUMMARY: We reviewed studies using contemporary magnetic resonance imaging (MRI) for the detection of bone metastasis in prostate cancer patients. MRI shows excellent diagnostic performance in finding patients with bone metastasis.

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.

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.