The diagnostic accuracy of high b-value diffusion- and T2-weighted imaging for the detection of prostate cancer: a meta-analysis

Purpose: This study aims to investigate the role of diffusion-weighted imaging (DWI) and T2-weighted imaging (T2WI) in combination for the detection of prostate cancer, specifically assessing the role of high b-values (> 1000 s/mm2), with a systematic review and meta-analysis of the existing published data.  Methods: The electronic databases MEDLINE, EMBASE, and OpenSIGLE were searched between inception and September 1, 2017. Eligible studies were those that reported the sensitivity and specificity of DWI and T2WI for the diagnosis of prostate cancer by visual assessment using a histopathologic reference standard. The QUADAS-2 critical appraisal tool was used to assess the quality of included studies. A meta-analysis with pooling of sensitivity, specificity, likelihood, and diagnostic odds ratios was undertaken, and a summary receiver-operating characteristics (sROC) curve was constructed. Predetermined subgroup analysis was also performed.  Results: Thirty-three studies were included in the final analysis, evaluating 2949 patients. The pooled sensitivity and specificity were 0.69 (95% CI 0.68–0.69) and 0.84 (95% CI 0.83–0.85), respectively, and the sROC AUC was 0.84 (95% CI 0.81–0.87). Subgroup analysis showed significantly better sensitivity with high b-values (> 1000 s/mm2). There was high statistical heterogeneity between studies.  Conclusion: The diagnostic accuracy of combined DWI and T2WI is good with high b-values (> 1000 s/mm2) seeming to improve overall sensitivity while maintaining specificity. However, further large-scale studies specifically looking at b-value choice are required before a categorical recommendation can be made

Ventricular-arterial uncoupling in heart failure with preserved ejection fraction after myocardial infarction in dogs - invasive versus echocardiographic evaluation

Heart failure with preserved left ventricular ejection fraction and abnormal diastolic function is commonly observed after recovery from an acute myocardial infarction. The aim of this study was to investigate the physiopathology of heart failure with preserved ejection fraction in a model of healed myocardial infarction in dogs.Journal ArticleResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe

Imagerie pour le traitement stéréotaxique des schwannomes vestibulaires. Facteurs d'erreur et corrections [Imaging for stereotaxic treatment of vestibular schwannomas. Error factors and corrections].

BACKGROUND AND PURPOSE: Gamma Knife radiosurgery treatment of vestibular schwannomas requires high accuracy for the prescribed dose definition and delivery. The main factors contributing to the error are the anatomical distortions of imaging modalities used for treatment planning. Imaging limitations and error factors are reviewed and detailed. Multimodality rationale for the delineation of vestibular schwannomas and surrounding structures are assessed. Quality control strategies are discussed and a distortion correction technique using a radiological phantom is presented. METHODS: Computed tomography is considered as the reference for spatial accuracy after appropriate scanner quality control using the stereotaxic fiducials system. Magnetic resonance imaging pulse sequence distortions are measured with a phantom designed for 3D non-linear local distortion evidence. A distortion correction transformation is computed from the phantom images and applied to the patient images. Results are verified using the stereotaxic fiducials system. RESULTS: Fiducials registration errors show spatial accuracy improvement, approaching computed tomography quality, after distortion correction of magnetic resonance images. CONCLUSIONS: The multimodal imaging approach for the dose planning of vestibular schwannomas radiosurgery treatment is relevant. Quality control of spatial accuracy for imaging modalities is mandatory and realistic in clinical routine