Related Experiment Video
Updated: Aug 20, 2026
![Semi-quantitative Assessment Using [18F]FDG Tracer in Patients with Severe Brain Injury](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F58641.jpg&w=3840&q=50)
Semi-quantitative Assessment Using [18F]FDG Tracer in Patients with Severe Brain Injury
Published on: November 9, 2018
[Evaluation of optimized injection dose and acquisition time using body mass index for three-dimensional whole-body
Keiichi Matsumoto1, Hajime Matsuura, Eiri Minota
1Department of Image-based Medicine, Institute of Biomedical Research and Innovation.
Objective:
The standardized uptake value (SUV) is a relative measure of tracer uptake in tissue used in (18)F-FDG PET. However, the quality of ordered subset expectation maximization (OS-EM) images is sensitive to the number of iterations, because a large number of iterations leads to images with checkerboard noise. The main advantage of data acquisition in the three-dimensional (3D) mode is the high sensitivity to better exploit the intrinsic spatial resolution and the lower injection dose given to patients. In the 3D mode, the scatter fraction is higher, and, for a given administered dose, the random fraction is higher than that in the two-dimensional mode, which implies that correction methods need to be more accurate. Moreover, in clinical oncology (18)F-FDG PET studies, patients have a wide variety of body shapes and sizes, which may impact image statistics. Consequently, it is necessary to make constant the acquisition (true) counts. The purpose of this study was to optimize injection dose and acquisition time in consideration of body mass index (BMI) for 3D whole-body (18)F-FDG PET.
Methods:
A dedicated PET scanner, SIEMENS ECAT EXACT HR(+), was used to scan images of clinical data. The injection dose for BMI of <14-19, 19-22, 22-25, and 25< (kg/m(2)) were, 92.5 MBq, 111.0 MBq, 129.5 MBq, and 148.0 MBq, respectively. The emission scan time per bed position for BMI of <14-19, 19-22, 22-25, and >25 (kg/m(2)) were, 120, 120, 180, and 240 sec, respectively. A total of 20 patient subjects were evaluated as to true counts per bin (T/bin) of sinogram data and measured activity concentrations for the region of interest in the liver section.
Results:
T/bin was stable using an optimized protocol that took into consideration the BMI for any type of body morphology. The overall coefficient of variation was 7.27% for radioactivity concentration. Additionally, Gaussian filtering (8 mm FWHM) after reconstruction by the OS-EM method provided stable SUV values even when the iteration number was increased 30 times over.
Conclusion:
Optimization of injection dose and acquisition time indicated that BMI was a clinically useful acquisition protocol for 3D whole-body (18)F-FDG PET.
More Related Videos
08:31Visualization and Quantification of Brown and Beige Adipose Tissues in Mice using [18F]FDG Micro-PET/MR Imaging
Published on: July 1, 2021
09:03Radiotracer Administration for High Temporal Resolution Positron Emission Tomography of the Human Brain: Application to FDG-fPET
Published on: October 22, 2019
Related Concept Videos
Imaging Studies II: Positron Emission Tomography and Scintigraphy
Fundamental Principles of PET
Positron Emission Tomography
One of the main requirements of a PET scan is a positron-emitting radioisotope, which is produced in a cyclotron and then attached to a substance used by the part of the body being...
Radiological Investigation III: Pulmonary Angiogram and PET Scan
Pulmonary Angiogram
A Pulmonary Angiogram is an invasive procedure involving injecting a contrast medium through a catheter threaded into the pulmonary artery or the right side of the heart to visualize the pulmonary vasculature. Computed Tomography (CT) scans have mainly replaced this...