Research on improvement of radioactivity quantitation in the human body in thallium-201 scintigraphic imaging study

2001 Fiscal Year Final Research Report Summary

• Project/Area Number: 12680838
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Biomedical engineering/Biological material science
• Research Institution: Kumamoto University
• Principal Investigator: KOJIMA Akihiro Kumamoto University, Radioisotope Research Center, Associate professor, アイソトープ総合センター, 助教授 (20161903)
• Co-Investigator(Kenkyū-buntansha): TOMIGUCHI Seiji Kumamoto University, School of Medicine, Lecturer, 医学部・附属病院, 講師 (20172182) ; MATSUMOTO Masanori Kumamoto University, College of Medical Science, Professor, 医療技術短期大学部, 教授 (90040229)
• Project Period (FY): 2000 – 2001
• Keywords: thallium-201 imaging / radioactivity quantitation / computer simulation / scatter correction / attenuation correction / gamma camera / myocardial phantom experiment / SPECT

Research Abstract

In the nuclear medicine study, it is very important to accurately estimate radioactivity distribution in the human body for reliable diagnosis with scintigraphic images. In this study, we investigated it about improvement of radioactivity quantitation in the human body in thallium-201 (Tl-201) scintigraphic imaging.
First, we simulated the photons emitted from Tl-201 in a phantom using Monte Carlo programs and a personal computer, and analyzed energy distributions for photons detected outside the phantom in detail. From the amount of non-scattered with true emission location information and scattered photons with false emission location information contained within the imaging window, we could develop a scatter correction method. Next, we performed Tl-201 planar imaging of a simple phantom using a gamma camera and applied this scatter correction method for the images acquired. The results showed that this scatter correction method can distinguish non-scattered photons from scattered photons more accurately and effectively in comparison with the conventional ones. In addition, to investigate how both scatter arid attenuation corrections can quantitatively improve SPECT values, Tl-201 myocardial SPECT imaging was performed using a dual-head gamma camera SPECT system and a sophisticated phantom. The attenuation correction method which was developed with the joint researchers in this project was employed. From the results of this myocardial SPECT experiments, in order to improve quantitative SPECT value in the myocardial imaging, it became clear to be important to apply the attenuation correction to accurately scatter-corrected SPECT images.
We consider that our results from this research may be very useful to clinical Tl-201 myocardial imaging with more accurate diagnostic information.