Faculty Bibliography

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.

OBJECTIVE:) DWI regarding diagnostic performance in the detection of prostate cancer. MATERIALS AND METHODS/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/CONCLUSIONS: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.

OBJECTIVE:To compare the image quality of low-tube-voltage and low-iodine-concentration-contrast-medium (LVLC) computed tomography urography (CTU) with iterative reconstruction (IR) with that of conventional CTU. MATERIALS AND METHODS:This prospective, multi-institutional, randomized controlled trial was performed at 16 hospitals using CT scanners from various vendors. Patients were randomly assigned to the following groups: 1) the LVLC-CTU (80 kVp and 240 mgI/mL) with IR group and 2) the conventional CTU (120 kVp and 350 mgI/mL) with filtered-back projection group. The overall diagnostic acceptability, sharpness, and noise were assessed. Additionally, the mean attenuation, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and figure of merit (FOM) in the urinary tract were evaluated. RESULTS:The study included 299 patients (LVLC-CTU group: 150 patients; conventional CTU group: 149 patients). The LVLC-CTU group had a significantly lower effective radiation dose (5.73 ± 4.04 vs. 8.43 ± 4.38 mSv) compared to the conventional CTU group. LVLC-CTU showed at least standard diagnostic acceptability (score ≥ 3), but it was non-inferior when compared to conventional CTU. The mean attenuation value, mean SNR, CNR, and FOM in all pre-defined segments of the urinary tract were significantly higher in the LVLC-CTU group than in the conventional CTU group. CONCLUSION:The diagnostic acceptability and quantitative image quality of LVLC-CTU with IR are not inferior to those of conventional CTU. Additionally, LVLC-CTU with IR is beneficial because both radiation exposure and total iodine load are reduced.

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/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:/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/CONCLUSIONS: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.

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/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:= 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/CONCLUSIONS: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.

OBJECTIVE:To retrospectively evaluate the radiologic findings for predicting rehabilitation outcomes in patients with chronic symptomatic os subfibulare. MATERIALS AND METHODS/METHODS:38 patients with chronic lateral ankle pain and os subfibulare underwent a standardized rehabilitation program. Rehabilitation outcome was evaluated after ≥3 months of intervention as the following: good response group (n = 20) without the need for further treatment and poor response group (n = 18) who underwent surgery after rehabilitation. Size, shape and location of os subfibulare, anterior talofibular ligament abnormality and attachment to the os subfibulare, interposition of fluid signal intensity between the os subfibulare and the fibula, and bone marrow edema in the os subfibulare on radiographs and MRI were evaluated by two radiologists blinded to rehabilitation outcomes and were compared between the two groups. RESULTS:The mean size of os subfibulare was significantly different between good and poor response groups: 7 versus 12 mm (p < 0.01), respectively. The prevalence of interposition of fluid signal intensity between the os subfibulare and the fibula and bone marrow edema in the os subfibulare on MRI was significantly different between the two groups (p < 0.01). However, other radiologic findings were not significantly different (p ≥ 0.08). The optimal size to classify the two groups was 9 mm with sensitivity of 83.3% and specificity of 80%. Inter-observer reliability was good to excellent (ICC = 0.991 for size and kappa = 0.735-0.923 for others). CONCLUSIONS:MRI may be used to predict rehabilitation outcome in patients with chronic symptomatic os subfibulare.

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/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/CONCLUSIONS:SWE shows good performance for the detection of PCa. However, specific recommendations regarding cutoff value cannot be made because of study heterogeneity.