Image reconstruction parameters and the standardized uptake value ratios in brain amyloid PET.

Objectives: The present study investigated various image reconstruction protocols for amyloid PET using phantom test criteria published by the Japanese Society of Nuclear Medicine (JSNM) and compared them with the composite standardized uptake value ratio (cSUVR) in clinical imaging.

Methods: Hoffman 3D phantoms and cylindrical phantoms were collected for 30 min according to the JSNM guidelines. Images were created under various reconstruction protocols by three physical evaluation items in the guidelines and were assessed: gray matter/white matter contrast (%contrast), uniformity (SDuROImean), and image noise [coefficient of variation (CV)].

Evaluation of Data-Driven Respiration Gating in Continuous Bed Motion in Lung Lesions.

Respiration gating is used in PET to prevent image quality degradation due to respiratory effects. In this study, we evaluated a type of data-driven respiration gating for continuous bed motion, OncoFreeze AI, which was implemented to improve image quality and the accuracy of semiquantitative uptake values affected by respiratory motion. F-FDG PET/CT was performed on 32 patients with lung lesions.

Cancer-associated fibroblast-dependent and -independent invasion of gastric cancer cells.

Purpose: Cancer cells are known to exhibit a cancer-associated fibroblast (CAF)-dependent invasive mode in the presence of CAFs. The purpose of this study was to investigate whether intrinsic factors of gastric cancer cells influence the CAF-dependent invasive mode of cancer cells.

Methods: We observed dynamic movement of CAFs, and cancer cells, by time-lapse imaging of 2-D and 3-D collagen invasion models, and evaluated invasion modes of gastric cancer cell lines (MKN-7, MKN-45, and HSC44PE).

Achievements of true whole-body imaging using a faster acquisition of the lower extremities in variable-speed continuous bed motion.

Variable-speed continuous bed motion F-fluorodeoxyglucose positron emission tomography/computed tomography (F-FDG-PET/CT), a reliable imaging technique, allows setting the bed motion speed for arbitrary sections of the body. The purpose of this study was to evaluate the relationship between the PET image quality and the bed speed following shortening of the scanning time for the lower extremities to achieve whole-body acquisition optimization of the examination time. Four sets of images were created by editing four-phase dynamic whole-body PET/CT images acquired at a bed speed of 6 and 14 mm/s in the trunk and lower extremities, respectively.