Promoting the use of the PI-QUAL score for prostate MRI quality: results from the ESOR Nicholas Gourtsoyiannis teaching fellowship

OBJECTIVES: The Prostate Imaging Quality (PI-QUAL) score is a new metric to evaluate the diagnostic quality of multiparametric magnetic resonance imaging (MRI) of the prostate. This study assesses the impact of an intervention, namely a prostate MRI quality training lecture, on the participant's ability to apply PI-QUAL. METHODS: Sixteen participants (radiologists, urologists, physicists, and computer scientists) of varying experience in reviewing diagnostic prostate MRI all assessed the image quality of ten examinations from different vendors and machines. Then, they attended a dedicated lecture followed by a hands-on workshop on MRI quality assessment using the PI-QUAL score. Five scans assessed by the participants were evaluated in the workshop using the PI-QUAL score for teaching purposes. After the course, the same participants evaluated the image quality of a new set of ten scans applying the PI-QUAL score. Results were assessed using receiver operating characteristic analysis. The reference standard was the PI-QUAL score assessed by one of the developers of PI-QUAL. RESULTS: There was a significant improvement in average area under the curve for the evaluation of image quality from baseline (0.59 [95 % confidence intervals: 0.50-0.66]) to post-teaching (0.96 [0.92-0.98]), an improvement of 0.37 [0.21-0.41] (p < 0.001). CONCLUSIONS: A teaching course (dedicated lecture + hands-on workshop) on PI-QUAL significantly improved the application of this scoring system to assess the quality of prostate MRI examinations. KEY POINTS: • A significant improvement in the application of PI-QUAL for the assessment of prostate MR image quality was observed after an educational intervention. • Appropriate training on image quality can be delivered to those involved in the acquisition and interpretation of prostate MRI. • Further investigation will be needed to understand the impact on improving the acquisition of high-quality diagnostic prostate MR examinations

Insights on Glucocorticoid Receptor Activity Modulation through the Binding of Rigid Steroids

Background: The glucocorticoid receptor (GR) is a transcription factor that regulates gene expression in a ligand-dependent fashion. This modular protein is one of the major pharmacological targets due to its involvement in both cause and treatment of many human diseases. Intense efforts have been made to get information about the molecular basis of GR activity. Methodology/Principal Findings: Here, the behavior of four GR-ligand complexes with different glucocorticoid and antiglucocorticoid properties were evaluated. The ability of GR-ligand complexes to oligomerize in vivo was analyzed by performing the novel Number and Brightness assay. Results showed that most of GR molecules form homodimers inside the nucleus upon ligand binding. Additionally, in vitro GR-DNA binding analyses suggest that ligand structure modulates GRDNA interaction dynamics rather than the receptor's ability to bind DNA. On the other hand, by coimmunoprecipitation studies we evaluated the in vivo interaction between the transcriptional intermediary factor 2 (TIF2) coactivator and different GR-ligand complexes. No correlation was found between GR intranuclear distribution, cofactor recruitment and the homodimerization process. Finally, Molecular determinants that support the observed experimental GR LBD-ligand/TIF2 interaction were found by Molecular Dynamics simulation. Conclusions/Significance: The data presented here sustain the idea that in vivo GR homodimerization inside the nucleus can be achieved in a DNA-independent fashion, without ruling out a dependent pathway as well. Moreover, since at least one GR-ligand complex is able to induce homodimer formation while preventing TIF2 coactivator interaction, results suggest that these two events might be independent from each other. Finally, 21-hydroxy-6,19-epoxyprogesterone arises as a selective glucocorticoid with potential pharmacological interest. Taking into account that GR homodimerization and cofactor recruitment are considered essential steps in the receptor activation pathway, results presented here contribute to understand how specific ligands influence GR behavior. © 2010 Presman et al.Fil:Presman, D.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Alvarez, L.D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Levi, V. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Martí, M.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Veleiro, A.S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Burton, G. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Pecci, A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina