Objective: The aim of this study was to investigate the relationship between the NEC and TOF-PET image quality.
Methods: The National Electrical Manufactures Association and International Electrical Commission (NEMA IEC) body phantom with a 10-mm diameter sphere was filled with an 18F-FDG solution with a 4:1 radioactivity ratio. The PET data were acquired in the three-dimensional list mode for 20 min. We created frame data ranging from 1 to 5 min acquisition time, which were then reconstructed using the baseline ordered-subsets expectation maximization (OSEM), the OSEM + point spread function (PSF) algorithm, OSEM + time-of-flight (TOF) algorithm and OSEM + PSF + TOF algorithm. The PET images were analyzed according to the noise-equivalent count (NEC), the coefficients of variance of the background (CVBG), the maximum count (CVmax) and the contrast (CVCONT). The results were compared with the recommended value according to the guidelines for the oncology FDG-PET/CT protocol.
Results: The NEC was higher than the recommended value at 3 min or longer acquisition time. The CVBG lower than 15% were obtained at 3 min acquisition time without TOF and at 2 min acquisition time with TOF. The CVBG of 10% or lower were obtained at 5 min or longer acquisition time without TOF and at 4 min or longer acquisition time with TOF. Both the CVmax and CVCONT lower than 10% were obtained at 3 min or longer acquisition time without TOF and at 1 min acquisition or longer with TOF. No particular relationships were observed between the frame number and degree of the variation in the image quality. The CVCONT significantly correlated with the NEC for the data reconstructed without TOF information, while there were no significant correlations between these useful metrics for the data reconstructed with TOF.
Conclusion: This study demonstrated that the NEC is not a useful metric for the evaluation of the image quality on TOF-PET images.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1007/s12149-015-1032-0 | DOI Listing |
J Pharm Anal
October 2024
National Key Laboratory of Chinese Medicine Modernization, State Key Laboratory of Component-based Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, 301617, China.
Identifying the compound formulae-related xenobiotics in bio-samples is full of challenges. Conventional strategies always exhibit the insufficiencies in overall coverage, analytical efficiency, and degree of automation, and the results highly rely on the personal knowledge and experience. The goal of this work was to establish a software-aided approach, by integrating ultra-high performance liquid chromatography/ion-mobility quadrupole time-of-flight mass spectrometry (UHPLC/IM-QTOF-MS) and in-house high-definition MS library, to enhance the identification of prototypes and metabolites of the compound formulae , taking Sishen formula (SSF) as a template.
View Article and Find Full Text PDFEur J Nucl Med Mol Imaging
January 2025
Laboratory of Neuroimaging and Innovative Molecular Tracers (NIMTlab), Geneva University Neurocenter and Faculty of Medicine, University of Geneva, Geneva, Switzerland.
Purpose: As dual-phase amyloid-PET can evaluate amyloid (A) and neurodegeneration (N) with a single tracer injection, dual-phase tau-PET might be able to provide both tau (T) and N. Our study aims to assess the association of early-phase tau-PET scans and F-fluorodeoxyglucose (FDG) PET and their comparability in discriminating Alzheimer's disease (AD) patients and differentiating neurodegenerative patterns.
Methods: 58 subjects evaluated at the Geneva Memory Center underwent dual-phase F-Flortaucipir-PET with early-phase acquisition (eTAU) and F-FDG-PET within 1 year.
Rofo
January 2025
Faculty of Medicine and University Hospital Cologne, Department of Diagnostic and Interventional Radiology, University Hospital Cologne, Cologne, Germany.
Online survey about the current status of CT protocols in hepatocellular carcinoma (HCC) in the year 2023/2024. Moreover, the usage of structured reporting using LI-RADS and mRECIST was surveyed and the results were compared with a survey from 2020.Radiologists working in outpatient or inpatient care in Germany were invited.
View Article and Find Full Text PDFInvest Radiol
January 2025
From the Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany (A. Schwarz, A. Simon, A.M.); Siemens Healthineers AG, Forchheim, Germany (A. Schwarz, C.H., J.D., A. Simon); Institute for Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany (F.K.W., S.G., M.S.); and Institut for Radiology, Pediatric and Neuroradiology, Helios Hospital, Schwerin, Germany (H.-J.R.).
Objective: Respiratory motion can affect image quality and thus affect the diagnostic accuracy of CT images by masking or mimicking relevant lung pathologies. CT examinations are often performed during deep inspiration and breath-hold to achieve optimal image quality. However, this can be challenging for certain patient groups, such as children, the elderly, or sedated patients.
View Article and Find Full Text PDFEat Weight Disord
January 2025
Eating Disorders Unit, Department of Neuroscience, University of Turin, Via Cherasco 15, 10126, Turin, Turin, Italy.
Eating disorders (EDs) pose significant challenges to mental and physical health, particularly among adolescents and young adults, with the COVID-19 pandemic exacerbating risk factors. Despite advancements in psychosocial and pharmacological treatments, improvements remain limited. Early intervention in EDs, inspired by the model developed for psychosis, emphasizes the importance of timely identification and treatment initiation to improve prognosis.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!