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.

Length of capsular contact on prostate MRI as a predictor of extracapsular extension: which is the most optimal sequence?

Background Length of capsular contact (LCC) is a promising biomarker for predicting extracapsular extension (ECE), but the most optimal magnetic resonance imaging (MRI) sequence for measuring LCC is yet to be determined. Purpose To evaluate LCC using different MRI sequences for determining ECE in prostate cancer. Material and Methods A total of 185 patients underwent prostate MRI followed by radical prostatectomy. LCC was measured separately on T2-weighted (T2W) images, apparent diffusion coefficient (ADC) maps, and dynamic contrast-enhanced (DCE) MRI. LCCs (LCCT2, LCCADC, LCCDCE, and LCCmax [greatest value of 3 LCCs]) were compared between sequences using Wilcoxon signed rank test and was tested for determining ECE using the Mann-Whitney U test, ROC curve analysis, and logistic regression analysis. Results There were no significant differences among LCCs ( P = 0.333-0.837). All LCCs were significantly greater in patients with ECE ( P < 0.001). The optimal threshold value for predicting ECE was >14, >13, >12, and >14 mm for LCCT2, LCCADC, LCCDCE, and LCCmax, respectively. LCCmax yielded the highest area under the curve (0.895) which was significantly greater than that by LCCADC (0.858, P = 0.030). Otherwise, there were no significant difference between LCCs ( P = 0.052-0.985). At univariate analysis, age, clinical stage, PSA, Gleason score, and all LCCs were significantly associated with ECE ( P < 0.001-0.040). At multivariate analysis, GS ( P ≤ 0.008) and all LCCs ( P < 0.001) were independently predictive factors. Conclusion LCC measured on any sequence was significantly different in patients with and without ECE and was independently associated with the presence of ECE. Although LCCmax showed the greatest ability to predict ECE, there was relatively equivalent performance among different MRI sequences.

PI-RADS version 2 for prediction of pathological downgrading after radical prostatectomy: a preliminary study in patients with biopsy-proven Gleason Score 7 (3+4) prostate cancer.

OBJECTIVES: To evaluate PI-RADSv2 for predicting pathological downgrading after radical prostatectomy (RP) in patients with biopsy-proven Gleason score (GS) 7(3+4) PC. METHODS: A total of 105 patients with biopsy-proven GS 7(3+4) PC who underwent multiparametric prostate MRI followed by RP were included. Two radiologists assigned PI-RADSv2 scores for each patient. Preoperative clinicopathological variables and PI-RADSv2 scores were compared between patients with and without downgrading after RP using the Wilcoxon rank sum test or Fisher's exact test. Logistic regression analyses with Firth's bias correction were performed to assess their association with downgrading. RESULTS: Pathological downgrading was identified in ten (9.5 %) patients. Prostate-specific antigen (PSA), PSA density, percentage of cores with GS 7(3+4), and greatest percentage of core length (GPCL) with GS 7(3+4) were significantly lower in patients with downgrading (p = 0.002-0.037). There was no significant difference in age and clinical stage (p = 0.537-0.755). PI-RADSv2 scores were significantly lower in patients with downgrading (3.8 versus 4.4, p = 0.012). At univariate logistic regression analysis, PSA, PSA density, and PI-RADSv2 scores were significant predictors of downgrading (p = 0.003-0.022). Multivariate analysis revealed only PSA density and PI-RADSv2 scores as independent predictors of downgrading (p = 0.014-0.042). CONCLUSIONS: The PI-RADSv2 scoring system was an independent predictor of pathological downgrading after RP in patients with biopsy-proven GS 7(3+4) PC. KEY POINTS: • PI-RADSv2 was an independent predictor of downgrading in biopsy-proven GS 7(3+4) PC • PSA density was also an independent predictor of downgrading • MRI may assist in identifying AS candidates in biopsy-proven GS 7(3+4) PC patients.

JOURNAL CLUB: Identification of Bone Metastasis With Routine Prostate MRI: A Study of Patients With Newly Diagnosed Prostate Cancer.

OBJECTIVE: The purpose of this study was to evaluate whether routine prostate MRI is adequate for detection of bone metastasis in patients with newly diagnosed prostate cancer. MATERIALS AND METHODS: The study included 308 patients with newly diagnosed prostate cancer who underwent prostate MRI. Two radiologists categorized MRI findings as normal, metastasis, or equivocal. Histologic analysis or best valuable comparator based on comprehensive review of images and clinical follow-up studies were used as reference standards. Clinicopathologic variables and MRI findings were compared between patients with and those without bone metastasis by use of chi-square and t tests. The diagnostic performance of prostate MRI for detecting bone metastasis was assessed by ROC analysis. Subgroup analysis was performed for patients at high risk of bone metastasis. RESULTS: Twenty-one (6.8%) patients had bone metastasis. They had significantly higher prostate-specific antigen levels (p = 0.015) and Gleason scores (p < 0.001) than those without bone metastasis. The diagnostic performance of MRI was as follows: sensitivity, 95.2%; specificity, 99-100%; positive predictive value, 86.9-100%; negative predictive value, 99.7%. For 119 patients at high risk of bone metastasis, these values were 95%, 100%, 100%, and 99%. Only 1 of the 21 (4.8%) patients had bone metastasis only in an area not explored with prostate MRI, that is, the thoracic spine. CONCLUSION: The diagnostic performance of routine prostate MRI for identifying bone metastasis in patients with newly diagnosed prostate cancer was excellent.

Preoperative Evaluation of Prostate Cancer Aggressiveness: Using ADC and ADC Ratio in Determining Gleason Score.

OBJECTIVE: The objective of our study was to evaluate apparent diffusion coefficient (ADC) and various ADC ratios in determining aggressiveness of prostate cancer. MATERIALS AND METHODS: One hundred sixty-five patients with biopsy-proven prostate cancer underwent 3-T MRI followed by radical prostatectomy. ADC and ADC ratios were calculated using the peripheral zone, transition zone, same zone as the tumor, and urinary bladder as references. ADC and ADC ratios were correlated with Gleason score using the Spearman correlation coefficient (ρ) and were compared between low-grade (Gleason score = 6) and high-grade (Gleason score ≥ 7) prostate cancer using the unpaired t test. ROC curves were used to compare diagnostic accuracies of ADC and ADC ratios in determining high-grade prostate cancer. RESULTS: Fifty-six (33.9%) and 109 (66.1%) patients had low- and high-grade prostate cancer, respectively. ADC (ρ = -0.476) and all ADC ratios (ρ = -0.397, -0.412, -0.381, and -0.474, respectively) correlated significantly with Gleason score (p < 0.001) and were significantly lower in patients with high-grade prostate cancer (p < 0.001). For predicting high-grade prostate cancer, tumor ADC and tumor-to-urinary bladder ADC ratio showed the highest AUC (0.794 and 0.790, respectively) but without statistically significant difference (p = 0.803). AUC of tumor ADC (0.794) was statistically significantly higher than those of the tumor-to-peripheral zone and tumor-to-transition zone ADC ratios (0.746, p = 0.039; 0.751, p = 0.027; respectively). AUC of tumor ADC was not statistically significantly higher than that of the tumor-to-tumor zone ADC ratio (0.763, p = 0.193). AUC calculated using the tumor-to-urinary bladder ADC ratio was statistically significantly higher than that using the tumor-to-transition zone ADC ratio (p = 0.028) and marginally higher than that from tumor-to-peripheral zone ADC ratio (p = 0.080). Otherwise, no significant differences were seen in the AUCs (p = 0.193-0.828). CONCLUSION: Both ADC and various ADC ratios correlated significantly with Gleason score and were significant predictors of high-grade prostate cancer. However, no benefit was found in using ADC ratio over ADC.

Early stage cervical cancer: role of magnetic resonance imaging after conization in determining residual tumor.

BACKGROUND: Although magnetic resonance imaging (MRI) is currently indispensable in the management of cervical cancer, its role in determining residual tumor in patients with cervical cancer after conization is not well known. PURPOSE: To evaluate the value of MRI after conization in determining residual tumor in patients with FIGO stage IA-IB1 cervical cancer. MATERIAL AND METHODS: In this retrospective study, 55 patients underwent conization followed by preoperative MRI and definitive surgery. Two radiologists evaluated the presence of residual tumor on MRI. MRI and preoperative clinical variables were compared between patients with and without residual tumor at final pathology using Student's t-test or Chi-square test. Association between variables and the presence of residual tumor was assessed using logistic regression analyses and receiver operating characteristic (ROC) curves. RESULTS: Residual tumor at final pathology was found in 30 (54.5%) patients. Patients with residual tumor were older, had greater SCC antigen, and more frequently had positive conization margins and identifiable tumor on MRI (P < 0.008). Multivariate analysis showed that age (P = 0.008; odds ratio [OR] = 1.140), positive conization margin (P = 0.016; OR = 11.919), and identifiable tumor on MRI (P = 0.038; OR = 6.926) were independently predictive of residual tumor. Areas under the curve (AUCs) calculated with age (0.693), SCC antigen (0.755), and identifiable tumor on MRI (0.727) were greater than lymphovascular space invasion (0.517) and histological subtype (0.520, P ≤ 0.049). Otherwise, there were no significant differences in the AUCs derived from different variables (P = 0.053-0.970). CONCLUSION: Identifiable tumor on MRI after conization in patients with early stage cervical cancer was an independent predictor of residual tumor at final pathology.

Exophytic renal angiomyolipoma and perirenal liposarcoma: revisiting the role of CT for differential diagnosis.

BACKGROUND: Exophytic renal angiomyolipoma and liposarcoma are two representative tumors in the retroperitoneum with fatty components that have potential to be misdiagnosed with each other. PURPOSE: To compare the computed tomography (CT) findings of exophytic renal angiomyolipoma and perirenal liposarcoma. MATERIAL AND METHODS: Fourteen and 16 cases with histologically-proven exophytic renal angiomyolipoma and perirenal liposarcoma, respectively, with preoperative CT from January 2000 to December 2013 were reviewed by two radiologists blinded to the clinical and pathological findings for an array of CT findings. These findings were compared between exophytic renal angiomyolipoma and perirenal liposarcoma using the Student t-test and Fisher's exact test. RESULTS: Patients with exophytic renal angiomyolipoma were younger (P = 0.001) without differences in sex (P = 1.000). Exophytic renal angiomyolipomas were smaller (P = 0.004) and more commonly showed the following findings: renal parenchymal defect (P < 0.001), multiple linear vessels (P = 0.026), aneurysmal dilatation of intratumoral vessels (P = 0.024), renal parenchymal vascular pedicle (P < 0.001), hemorrhage (P = 0.037), encapsulated margin (P = 0.001), and other intrarenal fatty lesions (P = 0.037). No significant difference was seen in laterality, renal hilar vascular pedicle, non-fatty soft tissue nodule, calcification, or kidney displacement (P = 0.236-1.000). CONCLUSION: Several CT findings were significantly different between exophytic renal angiomyolipoma and perirenal liposarcoma and may be helpful for differentiating between the two entities when confronting a fatty mass in the perirenal space.

Prostate cancer-specific mortality after radical prostatectomy: value of preoperative MRI.

BACKGROUND: Although magnetic resonance imaging (MRI) is currently indispensable in the preoperative setting of biopsy-proven prostate cancer, the value of preoperative MRI for predicting prostate cancer-specific mortality (PCSM) is not well known. PURPOSE: To evaluate the value of MRI for predicting PCSM in patients who underwent radical prostatectomy (RP) for localized prostate cancer. MATERIAL AND METHODS: A total of 318 patients underwent MRI followed by RP. MRI was assessed for the presence of clinically significant cancer using a five-point Likert scale, where ≥4 was considered positive. Cox proportional hazards regression analyses was used to determine the relationship of preoperative factors with PCSM. PCSM was calculated using the Kaplan-Meier method and compared between factors using the log-rank test. RESULTS: After a median follow-up of 104 months, 11 (3.5%) patients died of prostate cancer. One hundred and four (32.7%) patients had clinically significant prostate cancer on MRI. Univariate analysis revealed that Gleason grade, greatest percentage of involved core length (GPCL), and clinically significant cancer on MRI were significantly related to PCSM (P = 0.001-0.003). Multivariate analysis showed that GPCL (hazard ratio [HR], 1.028; 95% confidence interval [CI], 1.000-1.057; P = 0.048) and clinically significant cancer on MRI (HR, 10.903; 95% CI, 1.287-92.374; P = 0.028) were independent predictors of PCSM. The 5 - and 10-year PCSM rates were 0.6% and 1.3% in patients with GPCL <50% and 5.1% and 8.6% in those with GPCL ≥50% (P = 0.012). Patients without clinically significant cancer on MRI showed 5 - and 10-year PCSM rates of 0% and 0.5%, respectively, whereas those with clinically significant cancer on MRI showed rates of 8% and 14.2%, respectively (P < 0.001). CONCLUSION: Preoperative MRI and GPCL may be used to predict PCSM after RP.