Background: Estimates of effective dose (E) for cardiovascular CT are obtained from a scanner-provided dose metric, the dose-length product (DLP), and a conversion factor. These estimates may not adequately represent the risk of a specific scan to obese adults.
Objective: Our objective was to create dose maps sensitive to patient size and anatomy in the irradiated region from a patient's own CT images and compare measured E (EDoseMap) to doses determined from standard DLP conversion (EDLP) in obese adults.
Methods: 21 obese patients (mean body mass index, 39 kg/m(2)) underwent CT of the pulmonary veins, thoracic aorta, or coronary arteries. DLP values were converted to E. A Monte Carlo tool was used to simulate X-ray photon interaction with virtual phantoms created from each patient's image set. Organ doses were determined from dose maps. EDoseMap was computed as a weighted sum of organ doses multiplied by tissue-weighting factors.
Results: EDLP (mean ± SD, 5.7 ± 3.3 mSv) was larger than EDoseMap (3.4 ± 2.4 mSv) (difference = 2.3; P < .001).
Conclusion: Dose maps derived from patient CT images yielded lower effective doses than DLP conversion methods. Considering over all patient size, organ size, and tissue composition could lead to better dose metrics for obese patients.
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http://dx.doi.org/10.1016/j.jcct.2016.01.011 | DOI Listing |
Clin Radiol
December 2024
Department of Radiology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215006, China. Electronic address:
Aim: To assess transmural remission in patients with Crohn's disease using low-dose small bowel computed tomography (CT) perfusion scans.
Materials And Methods: Forty six patients were divided into active and remission phases based on Crohn's Disease Activity Index (CDAI) and C-reactive protein (CRP). Dual-source CT enterography with low-dose perfusion scans was conducted to generate perfusion parameter maps, including blood flow (BF), blood volume (BV), time to peak (TTP), mean transit time (MTT), and permeability of surface (PS).
Purpose: With the widespread introduction of dual energy computed tomography (DECT), applications utilizing the spectral information to perform material decomposition became available. Among these, a popular application is to decompose contrast-enhanced CT images into virtual non-contrast (VNC) or virtual non-iodine images and into iodine maps. In 2021, photon-counting CT (PCCT) was introduced, which is another spectral CT modality.
View Article and Find Full Text PDFJ Neuroimaging
January 2025
Toulouse NeuroImaging Center (ToNIC), INSERM, University of Toulouse Paul Sabatier, Toulouse, France.
Background And Purpose: Working memory, a primary cognitive domain, is often impaired in pediatric brain tumor survivors, affecting their attention and processing speed. This study investigated the long-term effects of treatments, including surgery, radiotherapy (RT), and chemotherapy (CT), on working memory tracts in children with posterior fossa tumors (PFTs) using resting-state functional MRI (rs-fMRI) and diffusion MRI tractography.
Methods: This study included 16 medulloblastoma (MB) survivors treated with postoperative RT and CT, 14 pilocytic astrocytoma (PA) survivors treated with surgery alone, and 16 healthy controls from the Imaging Memory after Pediatric Cancer in children, adolescents, and young adults study (NCT04324450).
Phys Med Biol
January 2025
Radiology, Stanford University, 1201 Welch Rd, P270, Stanford, California, 94305-6104, UNITED STATES.
Radiation dose and diagnostic image quality are opposing constraints in x-ray CT. Conventional methods do not fully account for organ-level radiation dose and noise when considering radiation risk and clinical task. In this work, we develop a pipeline to generate individualized organ-specific dose and noise at desired dose levels from clinical CT scans.
View Article and Find Full Text PDFEnviron Pollut
January 2025
Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China. Electronic address:
The co-existence of microplastics (MPs) and organic pollutants on agricultural ecosystems pose potential implications for both food safety and environmental integrity. The combined effects of MPs with Dechlorane Plus (DP), a newly listed banned flame retardant, remain unknown. This study explores the biological responses of soybean plants to exposure from polyethylene (PE) and polyvinyl chloride (PVC) MPs and DP.
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