Unlabelled: Attenuation correction (AC) of whole-body PET data in combined PET/MRI tomographs is expected to be a technical challenge. In this study, a potential solution based on a segmented attenuation map is proposed and evaluated in clinical PET/CT cases.
Methods: Segmentation of the attenuation map into 4 classes (background, lungs, fat, and soft tissue) was hypothesized to be sufficient for AC purposes. The segmentation was applied to CT-based attenuation maps from (18)F-FDG PET/CT oncologic examinations of 35 patients with 52 (18)F-FDG-avid lesions in the lungs (n = 15), bones (n = 21), and neck (n = 16). The standardized uptake values (SUVs) of the lesions were determined from PET images reconstructed with nonsegmented and segmented attenuation maps, and an experienced observer interpreted both PET images with no knowledge of the attenuation map status. The feasibility of the method was also evaluated with 2 patients who underwent both PET/CT and MRI.
Results: The use of a segmented attenuation map resulted in average SUV changes of 8% +/- 3% (mean +/- SD) for bone lesions, 4% +/- 2% for neck lesions, and 2% +/- 3% for lung lesions. The largest SUV change was 13.1%, for a lesion in the pelvic bone. There were no differences in the clinical interpretations made by the experienced observer with both types of attenuation maps.
Conclusion: A segmented attenuation map with 4 classes derived from CT data had only a small effect on the SUVs of (18)F-FDG-avid lesions and did not change the interpretation for any patient. This approach appears to be practical and valid for MRI-based AC.
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http://dx.doi.org/10.2967/jnumed.108.054726 | DOI Listing |
Microorganisms
December 2024
College of Resource and Environment, Shanxi Agricultural University, Taigu 030801, China.
Nanoplastics (NPs) and cadmium (Cd) coexist in soil, but the combined effects of NPs and Cd on the rhizosphere bacterial community remain unknown. In this study, high-throughput sequencing and PICRUSt2 functional analysis were employed to explore the individual and combined effects of polystyrene (PS) NPs (low concentration [N1, 100 mg·kg] and high concentration [N2, 1000 mg·kg]) and Cd (low concentration [C1, 0.6 mg·kg] and high concentration [C2, 4 mg·kg]) on the diversity, structural composition, and function of the rhizosphere bacterial community associated with Hance.
View Article and Find Full Text PDFJ Anaesthesiol Clin Pharmacol
August 2024
Department of Anesthesia, RNT Medical College, Udaipur, Rajasthan, India.
Background And Aims: An exaggerated hemodynamic response to endotracheal intubation is observed in hypertensive patients, and its attenuation proves challenging. The role of oral ivabradine, a unique heart rate-lowering drug with a favorable hemodynamic profile, is not yet studied. The aim of this study was to evaluate the effect of oral ivabradine on the attenuation of hemodynamic response to endotracheal intubation in hypertensive surgical patients assessed by rate pressure product (RPP), which is a very reliable indicator of myocardial oxygen demand.
View Article and Find Full Text PDFJ Anaesthesiol Clin Pharmacol
November 2024
Department of Anaesthesiology, Amrita Institute of Medical Sciences, Amrita Vishwa Vidyapeetham, Kochi, Kerala, India.
Background And Aims: Nasotracheal intubation evokes greater hemodynamic responses than oral intubation. We compared the heart rate (HR) and mean arterial pressure (MAP) responses following nasal intubation during opioid-free anesthesia (OFA) using intravenous lignocaine versus standard regimen using morphine in cancer patients undergoing tumor resection.
Material And Methods: This randomized, double-blinded study was conducted in 84 adults.
Curr Med Imaging
January 2025
Department of Radiology, The First Affiliated Hospital of Shenzhen University, Health Science Center, Shenzhen Second People's Hospital,3002 SunGangXi Road, Shenzhen, China.
Purpose: This study aims to evaluate the clinical efficacy of spectral dual-energy detector computed tomography (SDCT) and its associated parameters in diagnosing acute pulmonary embolism (APE).
Methods: Retrospective analysis of imaging data from 86 APE-diagnosed patients using SDCT was conducted. Virtual monoenergetic images (VMIs) at 40, 70, and 100 KeV, Iodine concentration (IC) maps, Electron Cloud Density Map (ECDM), Effective atomic number (Z-eff) maps, and Hounsfield unit attenuation plots (VMI slope) were reconstructed from pulmonary artery phase CT images.
Biol Pharm Bull
January 2025
Xiyuan Hospital, China Academy of Chinese Medical Sciences.
Idiopathic pulmonary fibrosis (PF) is an irreversible and chronic inflammatory condition with limited therapeutic options and a high mortality rate. We aimed to determine the possible role and mechanisms of wogonin (WGN) on PF. A rat model of PF was established with intratracheally administrated with bleomycin (BLM), followed by intravenously injecting with WGN and weekly body weight measurements for four weeks.
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