Matthew D. F. McInnes

Leiomyomas beyond the Uterus: Unusual Locations, Rare Manifestations

Uterine leiomyomas affect 20%-30% of women older than 35 years. Extrauterine leiomyomas are rarer, and they present a greater diagnostic challenge: These histologically benign tumors, which originate from smooth muscle cells, usually arise in the genitourinary tract (in the vulva, ovaries, urethra, and urinary bladder) but may arise in nearly any anatomic site. In addition, unusual growth patterns may be seen, including benign metastasizing leiomyoma, disseminated peritoneal leiomyomatosis, intravenous leiomyomatosis, parasitic leiomyoma, and retroperitoneal growth. In the presence of such a pattern, a synchronous uterine leiomyoma or a previous hysterectomy for removal of a primary uterine tumor may be indicative of the diagnosis. However, some extrauterine leiomyomas may mimic malignancies, and serious diagnostic errors may result. The most useful modalities for detecting extrauterine leiomyomas are ultrasonography, computed tomography, and magnetic resonance (MR) imaging. The superb contrast resolution and multiplanar capabilities of MR imaging make it particularly valuable for characterizing these tumors, which usually show low signal intensity similar to that of smooth muscle on T2-weighted images. The radiologists recognition of this and other characteristic features may help steer the clinician toward timely, appropriate management and away from unnecessary, potentially harmful treatment.

Association of Study Quality with Completeness of Reporting: Have Completeness of Reporting and Quality of Systematic Reviews and Meta-Analyses in Major Radiology Journals Changed Since Publication of the PRISMA Statement?

PURPOSE To evaluate whether completeness of reporting of systematic reviews and meta-analyses in major radiology journals has changed since publication of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement; a secondary objective is to evaluate whether completeness of reporting (ie, PRISMA) is associated with study quality (ie, Assessing the Methodological Quality of Systematic Reviews [AMSTAR]). MATERIALS AND METHODS Systematic reviews and meta-analyses published in major radiology journals between January 2007 and December 2011 were identified by searching MEDLINE with the modified Montori method. Studies were reviewed independently by two investigators and assessed for adherence to the AMSTAR and PRISMA checklists. The average results were analyzed to assess for change in mean score before and after PRISMA publication and to assess results over time; a Pearson correlation coefficient was calculated to assess for any association between PRISMA and AMSTAR results. RESULTS Included were 130 studies from 11 journals. Average PRISMA and AMSTAR results were 21.8 of 27 and 7.2 of 11, respectively. The average result was higher after publication of PRISMA, and PRISMA-reported items were 22.6 of 27 after publication of PRISMA versus 20.9 of 27 before publication of PRISMA; AMSTAR results were 7.7 of 11 after publication of PRISMA versus 6.7 of 11 before publication of PRISMA. There was a strong positive correlation (r = 0.86) between the PRISMA and AMSTAR results. There was high variability between journals. Radiology had the highest PRISMA reported items (24.7 of 27), and American Journal of Neuroradiology had the lowest (19.6 of 27). Two major areas for improvement include study protocol registration and assessment of risk of bias across studies (ie, publication bias). CONCLUSION In major radiology journal studies, there was modest improvement in completeness of reporting of systematic reviews and meta-analyses, assessed by PRISMA, which was strongly associated with higher study quality, assessed by AMSTAR. SUPPLEMENTAL MATERIAL http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13130273/-/DC1.

Benign Biliary Strictures: A Current Comprehensive Clinical and Imaging Review

OBJECTIVE There is a wide spectrum of nonneoplastic causes of biliary stricture that can pose a significant challenge to clinicians and radiologists. Imaging plays a key role in differentiating benign from malignant strictures, defining the extent, and directing the biopsy. We describe the salient clinical and imaging manifestations of benign biliary strictures that will help radiologists to accurately diagnose these entities. CONCLUSION Accurate diagnosis and management are based on correlating imaging findings with epidemiologic, clinical, and laboratory data. Cross-sectional imaging modalities permit precise localization of the site and length of the segment involved, thereby serving as a road map to surgery, and permit exclusion of underlying malignancy.

Percutaneous Image-guided Biopsy of the Spleen: Systematic Review and Meta-Analysis of the Complication Rate and Diagnostic Accuracy

PURPOSE To use meta-analysis to determine the complication rate and diagnostic accuracy of image-guided percutaneous needle biopsy of the spleen. MATERIALS AND METHODS Several electronic databases were searched through July 2010 without language restrictions. Two reviewers independently selected studies that met the inclusion criteria for the diagnostic accuracy and complication rate arms of the study. Study data were independently extracted by the two reviewers. The primary 2 × 2 data were investigated with a random-effects meta-analysis of sensitivity and specificity. The complication rate data were investigated with a random-effects meta-analysis; sensitivity analysis of complication rate, excluding needles larger than 18 gauge, was performed. RESULTS Four studies met the inclusion criteria for the diagnostic accuracy arm (639 patients), and nine met the inclusion criteria for the complication rate arm (741 patients). The meta-analysis showed a pooled sensitivity of 87.0% (95% confidence interval [CI]: 80.7%, 91.4%) and specificity of 96.4% (95% CI: 81.4%, 99.4%). The pooled major complication rate was 2.2% (95% CI: 0.8%, 5.6%). Sensitivity analysis with the removal of biopsies performed with needles larger than 18 gauge showed a major complication rate of 1.3% (95% CI: 0.6%, 2.5%). The most commonly encountered complications were hemorrhage followed by pain. CONCLUSION Image-guided percutaneous biopsy of the spleen demonstrates high diagnostic accuracy and a major complication rate, for needles 18 gauge or smaller, that is similar to that reported for the liver and kidney. This technique should be considered a favorable alternative to splenectomy.

Multiparametric MRI of solid renal masses: pearls and pitfalls.

Functional imaging [diffusion-weighted imaging (DWI) and dynamic contrast enhancement (DCE)] techniques combined with T2-weighted (T2W) and chemical-shift imaging (CSI), with or without urography, constitutes a comprehensive multiparametric (MP) MRI protocol of the kidneys. MP-MRI of the kidneys can be performed in a time-efficient manner. Breath-hold sequences and parallel imaging should be used to reduce examination time and improve image quality. Increased T2 signal intensity (SI) in a solid renal nodule is specific for renal cell carcinoma (RCC); whereas, low T2 SI can be seen in RCC, angiomyolipoma (AML), and haemorrhagic cysts. Low b-value DWI can replace conventional fat-suppressed T2W. DWI can be performed free-breathing (FB) with two b-values to reduce acquisition time without compromising imaging quality. RCC demonstrates restricted diffusion; however, restricted diffusion is commonly seen in AML and in chronic haemorrhage. CSI must be performed using the correct echo combination at 3 T or T2* effects can mimic intra-lesional fat. Two-dimensional (2D)-CSI has better image quality compared to three-dimensional (3D)-CSI, but volume averaging in small lesions can simulate intra-lesional fat using 2D techniques. SI decrease on CSI is present in both AML and clear cell RCC. Verification of internal enhancement with MRI can be challenging and is improved with image subtraction. Subtraction imaging is prone to errors related to spatial misregistration, which is ameliorated with expiratory phase imaging. SI ratios can be used to confirm subtle internal enhancement and enhancement curves are predictive of RCC subtype. MR urography using conventional extracellular gadolinium must account for T2* effects; however, gadoxetic acid enhanced urography is an alternative. The purpose of this review it to highlight important technical and interpretive pearls and pitfalls encountered with MP-MRI of solid renal masses.

Associations between residency selection strategies and doctor performance: a meta‐analysis

The purpose of this study was to use meta‐analysis to establish which of the information available to the resident selection committee is associated with resident or doctor performance.

Preferred Reporting Items for a Systematic Review and Meta-analysis of Diagnostic Test Accuracy Studies: The PRISMA-DTA Statement

Importance Systematic reviews of diagnostic test accuracy synthesize data from primary diagnostic studies that have evaluated the accuracy of 1 or more index tests against a reference standard, provide estimates of test performance, allow comparisons of the accuracy of different tests, and facilitate the identification of sources of variability in test accuracy. Objective To develop the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) diagnostic test accuracy guideline as a stand-alone extension of the PRISMA statement. Modifications to the PRISMA statement reflect the specific requirements for reporting of systematic reviews and meta-analyses of diagnostic test accuracy studies and the abstracts for these reviews. Design Established standards from the Enhancing the Quality and Transparency of Health Research (EQUATOR) Network were followed for the development of the guideline. The original PRISMA statement was used as a framework on which to modify and add items. A group of 24 multidisciplinary experts used a systematic review of articles on existing reporting guidelines and methods, a 3-round Delphi process, a consensus meeting, pilot testing, and iterative refinement to develop the PRISMA diagnostic test accuracy guideline. The final version of the PRISMA diagnostic test accuracy guideline checklist was approved by the group. Findings The systematic review (produced 64 items) and the Delphi process (provided feedback on 7 proposed items; 1 item was later split into 2 items) identified 71 potentially relevant items for consideration. The Delphi process reduced these to 60 items that were discussed at the consensus meeting. Following the meeting, pilot testing and iterative feedback were used to generate the 27-item PRISMA diagnostic test accuracy checklist. To reflect specific or optimal contemporary systematic review methods for diagnostic test accuracy, 8 of the 27 original PRISMA items were left unchanged, 17 were modified, 2 were added, and 2 were omitted. Conclusions and Relevance The 27-item PRISMA diagnostic test accuracy checklist provides specific guidance for reporting of systematic reviews. The PRISMA diagnostic test accuracy guideline can facilitate the transparent reporting of reviews, and may assist in the evaluation of validity and applicability, enhance replicability of reviews, and make the results from systematic reviews of diagnostic test accuracy studies more useful.

Pitfalls of Systematic Reviews and Meta-Analyses in Imaging Research

Systematic reviews of imaging research represent a tool to better understand test accuracy or the efficacy of interventions. Like any type of research, appropriate methods must be applied to optimize quality. The purpose of this review is to outline common pitfalls in performing systematic reviews of imaging research, with a focus on challenges particular to performing reviews of diagnostic accuracy studies. The following challenges are highlighted: posing relevant review questions, conducting comprehensive literature searches, assessing for bias in included studies, testing for heterogeneity and publication bias, pooling results across studies, and forming appropriate conclusions. By guiding authors on how to overcome these, the hope is that published reviews in imaging research will be of higher quality and have a positive impact on clinical practice. In addition, the review aims to educate readers of reviews so they become aware of crucial elements of systematic reviews that could bias review results.

Diagnosis of Sarcomatoid Renal Cell Carcinoma With CT: Evaluation by Qualitative Imaging Features and Texture Analysis.

OBJECTIVE The objective of our study was to determine whether CT findings, including texture analysis, can differentiate sarcomatoid renal cell carcinoma (RCC) from clear cell RCC. MATERIALS AND METHODS A retrospective case-control study was performed of consecutive patients with a histologic diagnosis of sarcomatoid RCC (n = 20) and clear cell RCC (n = 25) who underwent preoperative CT over a 3-year period. The CT images were independently reviewed by two blinded abdominal radiologists; they evaluated the following: tumor heterogeneity, tumor margin, calcification, intratumoral neovascularity, peritumoral neovascularity, renal sinus invasion, renal vein invasion, and adjacent organ invasion. Interobserver agreement was assessed using the Cohen kappa coefficient, and results were compared between groups using an independent Student t test and the chi-square test with a Bonferroni correction. For texture analysis, gray-level co-occurrence and run-length matrix features were extracted and compared using Mann-Whitney U tests. ROC curves for each tumor were constructed, and AUCs were calculated. RESULTS Overall, sarcomatoid RCCs were larger than clear cell RCCs, measuring 77 ± 27 mm (mean ± SD) compared with 50 ± 29 mm (p = 0.003), respectively; however, there was no difference in tumor size between the tumors that were compared using texture analysis or subjective analysis (p = 0.06 and 0.03, respectively). From the subjective analysis, only peritumoral neovascularity (readers 1 and 2: 70% and 70% sarcomatoid RCCs vs 0% and 41.6% clear cell RCCs, respectively; p = 0.001) and the size of the peritumoral vessels (p < 0.001) differed between sarcomatoid RCCs and clear cell RCCs, and interobserver agreement was fair (κ = 0.38). Other subjective imaging features did not differ between the tumors (p > 0.005). There was greater run-length nonuniformity and greater gray-level nonuniformity in sarcomatoid RCCs than in clear cell RCCs (p = 0.03 and p = 0.04, respectively). The combined textural features identified sarcomatoid RCC with an AUC of 0.81 ± 0.08 (standard error) (p < 0.0001). CONCLUSION Large tumor size, the presence of peritumoral neovascularity, and larger peritumoral vessels are features that are more commonly associated with sarcomatoid RCCs than with clear cell RCCs. Sarcomatoid RCCs are also more heterogeneous by texture analysis than clear cell RCCs.

Evaluation of the European Society of Urogenital Radiology (ESUR) PI-RADS scoring system for assessment of extra-prostatic extension in prostatic carcinoma

INTRODUCTION To evaluate extra-prostatic extension (EPE) comparing PI-RADS to non-standardized reporting. MATERIALS AND METHODS With IRB approval, 145 consecutive patients underwent radical prostatectomy (RP) and multi-parametric (T2W+DWI+DCE) MRI between 2012 and 2013. Eighty patients (66.3% with EPE) were staged without PI-RADS and 65 patients (64.6% with EPE) were staged using a 5-point PI-RADS scoring system. Studies were reported by fellowship-trained radiologists in routine clinical practice. Individual PIRADS scores were assessed using ROC to determine the score which optimized sensitivity/specificity. Diagnostic accuracy for EPE was compared with/without PI-RADS using the McNemar test. Subgroup analysis by radiologist experience was performed using Spearman correlation and chi-square. RESULTS Area under ROC curve for EPE using PI-RADS was 0.62 and optimal sensitivity/specificity was achieved with PI-RADS score ≥ 3. Compared to non-standardized reporting, sensitivity for EPE improved with PI-RADS (59.5% [49.1-68.2] vs. 24.5% [16.7-31.2]), p=0.01; with no difference in specificity (68.0% [50.5-82.6]) vs. (75.0% [60.1-87.6]), p=0.06. Overall accuracy improved with PI-RADS (62.7% [49.6-73.6] vs. 42.0% [31.7-50.7%]), p=0.006. Diagnostic accuracy was better among experienced radiologists without PI-RADS (p=0.005); however, there was no difference in accuracy by reader experience using PI-RADS (p=0.24). CONCLUSION The PI-RADS criteria for EPE improves sensitivity without reducing specificity. PI-RADS may reduce differences in accuracy by reader experience.