Improvement of image quality for small lesion sizes in 18F-FDG prone breast silicon photomultiplier-based PET/CT imaging

Articles in Press

Document Type : Technical note

Authors

1 Department of Radiology, Shimane University Hospital

2 Department of Radiology, Faculty of Medicine, Shimane University

3 Division of Medical Informatics, Shimane University Hospital

10.22038/aojnmb.2024.78080.1553

Abstract

Objective

We investigated image quality and standardized uptake values (SUVs) for different lesion sizes using clinical data generated by 18F-FDG-prone breast silicon photomultiplier (SiPM)-based positron emission tomography/computed tomography (PET/CT).

Methods

We evaluated the effect of point-spread function (PSF) modeling and Gaussian filtering (Gau) and determined the optimal reconstruction conditions. We compared the signal-to-noise ratio (SNR), contrast, %coefficient of variation (%CV), SUV, and Likert scale score between ordered-subset expectation maximization (OSEM)+time-of-flight (TOF) and OSEM+TOF+PSF in phantom and clinical studies. The conventional image was generated with OSEM+TOF_Gau 6 mm. The National Electrical Manufacturers Association body phantom with 10-mm hot sphere data was acquired for 5 min. Twenty-six patients (40 lesions, ranging from 3.7 to 63.0 mm) were examined using prone breast PET/CT with a breast positioner for breast cancer staging. PET data were acquired 125 ± 9.7 min after intravenous injection of 220 ± 16.1 MBq at 5 min/bed.

Results

In the phantom study, a high SNR was obtained from a 3- to 5-mm Gaussian filter for OSEM+TOF+PSF. The contrast obtained with OSEM+TOF without Gaussian filtering was superior to that obtained with OSEM+TOF+PSF_Gau 4 mm. In the clinical study, the image quality depended on lesion size. The average SNR was significantly higher at 40.8% for lesions > 20 mm with OSEM+TOF_Gau 6 mm than with OSEM+TOF without Gaussian filtering. The average contrast for lesions ≤ 10 mm was significantly higher by 42.0% with OSEM+TOF without Gaussian filtering than with OSEM+TOF_Gau 6 mm. The average SUVmax of OSEM+TOF without Gaussian filtering significantly increased by 53.3% for lesions ≤ 10 mm.

Conclusion

OSEM+TOF without Gaussian filtering provided good contrast and quantitative value for small lesions.

Keywords

Main Subjects

Asia Oceania Journal of Nuclear Medicine and Biology

Articles in Press, Accepted Manuscript
Available Online from 09 July 2024

Files

Share

How to cite

Statistics