en Radiation Biology Radiation Biology اخبار و تازه‌ها News and Features <div style="text-align: justify;"><span style="font-size:10pt"><span style="text-justify:newspaper"><span style="text-kashida-space:50%"><span style="line-height:119%"><span style="font-family:Calibri"><span style="color:black"><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">The Physics Sessions of the 40th Iranian Congress of Radiology (IRC 2025) focused on improving patient safety, diagnostic accuracy, and evidence-based practice across ionizing and non-ionizing imaging modalities. The lectures emphasized that high-quality imaging requires effective radiation protection, rigorous quality assurance (QA), and well-trained professionals. A major theme of the congress was the development of a strong radiation safety culture based on justification, optimization (ALARA), and dose limitation. Speakers highlighted the importance of leadership, structured education, standardized safety protocols, and transparent communication in reducing unnecessary radiation exposure to patients and healthcare workers. Another key topic was quality control in diagnostic imaging. Properly implemented QA programs improve image quality while minimizing radiation dose. Monitoring parameters such as spatial and contrast resolution, image noise, artifacts, and contrast-to-noise ratio (CNR) is essential for maintaining diagnostic reliability and reducing repeat examinations. The congress also reviewed evolving evidence regarding patient lead shielding. Recent findings indicate that routine shielding may provide limited benefit in modern imaging systems and can occasionally interfere with automatic exposure control (AEC) or image quality. Current radiation protection strategies increasingly emphasize optimized imaging parameters, precise collimation, and avoidance of repeat imaging. Sessions on neonatal and obstetric ultrasound safety stressed the importance of monitoring Thermal Index (TI) and Mechanical Index (MI), minimizing scan duration, and improving operator awareness. Discussions on the Linear No-Threshold (LNT) model concluded that despite evidence of non-linear biological responses at low doses, the LNT model remains a practical and conservative framework for radiation protection policy.</span></span></span></span></span></span></span></span></span></div> Radiation safety culture, ALARA, ultrasound safety, linear no-threshold model, medical imaging optimization. 921 924 http://ijrr.com/browse.php?a_code=A-10-1-1594&slc_lang=en&sid=1 H. Mozdarani 7900319475328460034493 7900319475328460034493 No Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran M. Bakhshandeh Mohsen Bakhshandeh 7900319475328460034494 7900319475328460034494 Yes Department of Radiology Technology, School of Allied Medical Faculty, Shahid Beheshti University of Medical Sciences, Tehran, Iran H. Keivan 7900319475328460034495 7900319475328460034495 No School of Allied Medical Sciences, Shahroud University of Medical Sciences, Shahroud, Iran V. Changizi 7900319475328460034496 7900319475328460034496 No Department of Radiology Technology and Radiotherapy, School of Allied Medical Sciences, Tehran University of Medical Sciences, Tehran, Iran O. Azadbakht 7900319475328460034497 7900319475328460034497 No Behbahan Faculty of Medical Sciences, Behbahan, Iran H. Zamani 7900319475328460034498 7900319475328460034498 No Department of Medical Physics, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran R.K. Samani 7900319475328460034499 7900319475328460034499 No Department of Medical Physics and Radiology, School of Allied Medical Sciences, Shahrekord University of Medical Sciences, Shahrekord, Iran E. Soleimani 7900319475328460034500 7900319475328460034500 No Department of Radiology Technology, School of Allied Medical Faculty, Shahid Beheshti University of Medical Sciences, Tehran, Iran S.M.J. Mortazavi 7900319475328460034501 7900319475328460034501 No Department of Medical Physics, School of Medicine Shiraz University of Medical Sciences Shiraz Iran