Optimizing time-of-flight of PET/CT image quality via penalty β value in Bayesian penalized likelihood reconstruction algorithm

• Published in: Radiography (London, England. 1995) Vol. 31; no. 1; pp. 343 - 349
• Main Authors: Murat, H., Zulkifli, M.A.A., Said, M.A., Awang Kechik, M., Tahir, D., Abdul Karim, M.K.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.01.2025
• Subjects: Algorithms; Bayes Theorem; Bayesian penalized likelihood; Fluorodeoxyglucose F18; Humans; Image Processing, Computer-Assisted - methods; Image quality; Image reconstruction; Likelihood Functions; Phantoms, Imaging; Positron emission tomography; Positron Emission Tomography Computed Tomography - methods; Radiopharmaceuticals; Signal-To-Noise Ratio; Time-of-flight; β value; Image quality; Bayesian penalized likelihood; Positron emission tomography; β value; Time-of-flight; Image reconstruction
• ISSN: 1078-8174; 1532-2831; 1532-2831
• DOI: 10.1016/j.radi.2024.12.011

Optimizing the image quality of Positron Emission Tomography/Computed Tomography (PET/CT) systems is crucial for effective monitoring, diagnosis, and treatment planning in oncology. This study evaluates the impact of time-of-flight (TOF) on PET/CT performance, focusing on varying penalty β values within Q. Clear reconstruction algorithm. The study measured signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) using the Discovery MI PET/CT scanner and NEMA IQ phantom filled with the radiotracer fluorodeoxyglucose (18F-FDG). PET/CT scans were performed with and without TOF using β values of 100, 500, 1000, 1500, 2000, and 3000. Pixel intensity values were measured using ImageJ software, and SNR and CNR were calculated. Results indicated that increasing β values improved SNR and CNR for both non-TOF and TOF images. At a β value of 100, SNR and CNR increased across all sphere sizes (10 mm, 13 mm, 17 mm, 22 mm, 28 mm, 37 mm) when comparing non-TOF and TOF images. However, β values of 500 or higher led to decreased SNR and CNR, particularly in larger spheres (22 mm, 28 mm, 37 mm), when TOF was utilized. These findings underscore the importance of optimizing β values and employing TOF reconstruction in PET/CT scans to achieve the highest possible image quality. In clinical practice, practitioners should adjust β values in accordance with routine protocols, considering the size of the target region and the use of TOF reconstruction.