en Radiation Biology Radiation Biology تحقيق بديع Original Research <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="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Background</span></span></span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-weight:bold"><span style="language:en-US">:</span></span></span></span></span> <span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">Computed tomography (CT) is a crucial technique in clinical practice for diagnosing thoracic pathologies. However, the risk associated with ionizing radiation requires measures to reduce patient exposure. </span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Materials and Methods: </span></span></span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">This study aims to optimize thoracic CT protocols on a multislice CT scanner, using both objective and subjective analyses of image quality to decrease radiation dose without compromising diagnostic accuracy. A 16-channel CT scanner with automatic tube current modulation (ATCM) was utilized, along with an analytical phantom for objective evaluation. Six protocols with different standard deviation values were selected, including three used in clinical routines and three additional ones for testing. Parameters such as spatial resolution, low contrast resolution, noise, and dosimetry were assessed. Subjective Image Quality evaluation was conducted through visual grading analysis (VGA). </span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Results: </span></span></span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">Optimized protocols were selected based on acceptable image quality and dose results. Data were statistically analyzed, demonstrating that optimized protocols showed a significant reduction in radiation dose while maintaining adequate diagnostic quality. </span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="color:#1f497d"><span style="font-style:italic"><span style="font-weight:bold"><span style="language:en-US">Conclusion: </span></span></span></span></span></span><span lang="en-US" style="font-size:9.0pt"><span style="font-family:Calibri"><span style="language:en-US">This study contributes to clinical practice by adhering to the ALARA (As Low As Reasonably Achievable) principles of dose reduction, ensuring accurate and safe diagnoses in thoracic CT examinations.</span></span></span></span></span></span></span></span></span></div> Computed tomography, dose optimization, image quality, thoracic imaging. 379 385 http://ijrr.com/browse.php?a_code=A-10-1-1340&slc_lang=en&sid=1 R.A.C. Guassu 7900319475328460031093 7900319475328460031093 No Department of Physics and Biophysics, Sao Paulo State University Julio de Mesquita Filho, Institute of Bioscience, R. Prof. Dr. Antônio Celso Wagner Zanin, 250 - Distrito de Rubião Junior, Botucatu, Brazil .A. Santana Souza 7900319475328460031094 7900319475328460031094 No Department of Physics and Biophysics, Sao Paulo State University Julio de Mesquita Filho, Institute of Bioscience, R. Prof. Dr. Antônio Celso Wagner Zanin, 250 - Distrito de Rubião Junior, Botucatu, Brazil M. Alvarez 7900319475328460031095 7900319475328460031095 No São Paulo State University Julio de Mesquita Filho, Medical School, Av. Prof. Mário Rubens Guimarães Montenegro - UNESP, Botucatu, Brazil S.M. Ribeiro 7900319475328460031096 7900319475328460031096 No São Paulo State University Julio de Mesquita Filho, Medical School, Av. Prof. Mário Rubens Guimarães Montenegro - UNESP, Botucatu, Brazil J.C.S. Trindade Filho 7900319475328460031097 7900319475328460031097 No São Paulo State University Julio de Mesquita Filho, Medical School, Av. Prof. Mário Rubens Guimarães Montenegro - UNESP, Botucatu, Brazil D.R. Pina diana.pina@unesp.br 7900319475328460031098 7900319475328460031098 Yes São Paulo State University Julio de Mesquita Filho, Medical School, Av. Prof. Mário Rubens Guimarães Montenegro - UNESP, Botucatu, Brazil