STUDY OF TC-99M USE IN HEPATOBILIARY FUNCTION EXAMINATION: A BASIC NUCLEAR TECHNIQUE PERSPECTIVE

Abstract

Hepatobiliary function testing is a crucial pillar in the diagnosis and management of various liver and biliary tract diseases, which are now a significant global health challenge with the increasing prevalence of degenerative and infectious diseases. Nuclear medicine techniques, particularly the use of Technetium-99m (Tc-99m)-based radiopharmaceuticals, have become the gold standard for the non-invasive evaluation of gallbladder motility, bile flow, and bilirubin clearance efficiency. However, optimization of nuclear image acquisition and reconstruction parameters, based on radiation physics and detector principles, remains frequently neglected in daily clinical practice, creating a gap between the full diagnostic potential of this technology and its application. The urgency of this research is furthered by the rising cost of healthcare and the need for efficient and accurate diagnostic methods, which require a thorough understanding of the technical fundamentals to maximize the clinical value of nuclear imaging modalities. This study aims to comprehensively evaluate the effectiveness and optimization of the use of the radiopharmaceutical Tc-99m-Sestamibi in hepatobiliary function examinations through an in-depth analysis of image acquisition parameters and reconstruction techniques, with a theoretical framework based on the principles of nuclear physics and biophysics, with the main hypothesis that optimization of acquisition and reconstruction parameters can significantly improve the diagnostic quality of hepatobiliary images. The study design is an analytical observational study combining retrospective analysis of clinical data and computational simulation, involving 150 patients undergoing hepatobiliary examinations with Tc-99m-Sestamibi. The main instrument used is a dual-detector SPECT/CT gamma camera imaging system, and image quality was evaluated using quantitative metrics (SNR, CNR) as well as visual assessment by an independent specialist. The study procedure includes re-analysis of acquisition data with varying parameters and the application of different reconstruction algorithms, followed by comparative statistical analysis. The analysis results showed that optimizing the number of acquisition angles from 32 to 64 angles significantly improved the spatial resolution of hepatobiliary images (mean SNR increase of 15%, p < 0.01) and the accuracy of abnormality detection (sensitivity increase from 85% to 92%, specificity from 90% to 95%). The use of the Iterative Reconstruction algorithm with 10 iterations and 15 subsets proved superior to Filtered Back Projection in reducing artifacts and increasing the contrast of abnormal lesions (effect size Cohen's d = 0.75, p < 0.001). Secondary analysis showed that variations in radiopharmaceutical doses within the recommended range did not significantly impact image quality, but lower doses increased SNR in obese patients. An unexpected finding was a positive correlation between the duration of acquisition time per angle and motion artifacts. This study concluded that optimizing SPECT/CT image acquisition and reconstruction parameters with Tc-99m-Sestamibi substantially improved the diagnostic quality of hepatobiliary function examinations, which directly contributed to improved clinical accuracy. The theoretical contribution includes a deeper understanding of the relationship between nuclear physics and medical image interpretation, while the practical contribution is the provision of technical guidance that can be implemented in nuclear medicine facilities, with recommendations for the implementation of optimized protocols and further research on personalized imaging parameters.