Image quality evaluation of real low-dose breast PET

Abstract

Purpose To evaluate the clinical feasibility of high-resolution dedicated breast positron emission tomography (dbPET) with real low-dose 18F-2-fluorodeoxy-d-glucose (18F-FDG) by comparing images acquired with full-dose FDG. Materials and methods Nine women with no history of breast cancer and previously scanned by dbPET injected with a clinical 18F-FDG dose (3 MBq/kg) were enrolled. They were injected with 50% of the clinical 18F-FDG dose and scanned with dbPET for 10 min for each breast 60 and 90 min after injection. To investigate the effect of the scan start time and acquisition time on image quality, list-mode data were divided into 1, 3, 5, and 7 min (and 10 min with 50% FDG injected) from the start of acquisition and reconstructed. The reconstructed images were visually and quantitatively compared for contrast between mammary gland and fat (contrast) and for coefficient of variation (CV) in the mammary gland. Results In visual evaluation, the contrast between the mammary gland and fat acquired at a 50% dose for 7 min was comparable and even better in smoothness than that in the images acquired at a 100% dose. No visual difference between the images with a 50% dose was found with scan start times 60 and 90 min after injection. Quantitative evaluation showed a slightly lower contrast in the image at 60 min after 50% dosing, with no difference between acquisition times. There was no difference in CV between conditions; however, smoothness decreased with shorter acquisition time in all conditions. Conclusions The quality of dbPET images with a 50% FDG dose was high enough for clinical application. Although the optimal scan start time for improved lesion-to-background mammary gland contrast remained unknown in this study, it will be clarified in future studies of breast cancer patients.

Clinical Utility of Breast Ultrasound Images Synthesized by a Generative Adversarial Network

“…In recent years, breast imaging diagnostics have advanced significantly, with improvements in imaging technology and diagnostic accuracy [27][28][29][30][31][32]. This progress is not only due to enhancements in the quality of mammography and ultrasound images and the establishment of more refined reading techniques but also to the emergence of new modalities such as contrast-enhanced Magnetic Resonance Imaging (MRI), Positron Emission Tomography/Computed Tomography (PET/CT), and PET mammography.…”

Proposal to Improve the Image Quality of Short-Acquisition Time-Dedicated Breast Positron Emission Tomography Using the Pix2pix Generative Adversarial Network

“…Thus, even images with fewer RI counts caused by reduced FDG dose can be improved. A previous study on actual low-dose dbPET revealed that a clinically acceptable image quality is obtained at approximately 25–50% of the dose for conventional whole-body FDG PET [ 15 ]. In this study, images were sampled from the start time of collection; thus, the earlier the start time of acquisition, the higher the RI counts, and the later the start time of acquisition, the lower the RI counts, even within the same minute.…”

“…However, this is a very complicated method, and in practice, it is difficult to do in each case. Therefore, we chose this simple method used in a previous study [ 15 ]. Accordingly, we can approximately assume that (A% acquisition times) × (B% dose) image” = “(B% acquisition times) × (A% dose) image.…”

“…Repeated exposure may also increase the likelihood of developing malignant tumors over a lifetime [ 14 ]. This problem may be solved by reducing the drug dosage; however, poor diagnostic performance due to reduced image quality is a concern [ 15 ].…”