Purpose: To investigate within phantoms the minimum CT dose allowed for accurate attenuation correction of PET data and to quantify the effective dose reduction when a CT for this purpose is incorporated in the clinical setting.
Methods: The NEMA image quality phantom was scanned within a large parallelepiped container. Twenty-one different CT images were acquired to correct attenuation of PET raw data. Radiation dose and image quality were evaluated. Thirty-one patients with proven multiple myeloma who underwent a dual tracer PET/CT scan were retrospectively reviewed. F-fluorodeoxyglucose PET/CT included a diagnostic whole-body low dose CT (WBLDCT: 120 kV-80mAs) and C-Methionine PET/CT included a whole-body ultra-low dose CT (WBULDCT) for attenuation correction (100 kV-40mAs). Effective dose and image quality were analysed.
Results: Only the two lowest radiation dose conditions (80 kV-20mAs and 80 kV-10mAs) produced artifacts in CT images that degraded corrected PET images. For all the other conditions (CTDI ≥ 0.43 mGy), PET contrast recovery coefficients varied less than ± 1.2%. Patients received a median dose of 6.4 mSv from diagnostic CT and 2.1 mSv from the attenuation correction CT. Despite the worse image quality of this CT, 94.8% of bone lesions were identifiable.
Conclusion: Phantom experiments showed that an ultra-low dose CT can be implemented in PET/CT procedures without any noticeable degradation in the attenuation corrected PET scan. The replacement of the standard CT for this ultra-low dose CT in clinical PET/CT scans involves a significant radiation dose reduction.
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http://dx.doi.org/10.1016/j.ejmp.2021.03.019 | DOI Listing |
Insights Imaging
January 2025
Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China.
Objectives: To investigate the image quality and diagnostic performance with ultra-low dose dual-layer detector spectral CT (DLSCT) by various reconstruction techniques for evaluation of pulmonary nodules.
Materials And Methods: Between April 2023 and December 2023, patients with suspected pulmonary nodules were prospectively enrolled and underwent regular-dose chest CT (RDCT; 120 kVp/automatic tube current) and ultra-low dose CT (ULDCT; 100 kVp/10 mAs) on a DLSCT scanner. ULDCT was reconstructed with hybrid iterative reconstruction (HIR), electron density map (EDM), and virtual monoenergetic images at 40 keV and 70 keV.
Pharmaceuticals (Basel)
December 2024
Department of Anesthesiology, Cathay General Hospital, Taipei 106, Taiwan.
Background: Morphine analgesic tolerance (MAT) limits the clinical application of morphine in the management of chronic pain. IIK7 is a melatonin type 2 (MT2) receptor agonist known to have antioxidant properties. Oxidative stress is recognized as a critical factor in MAT.
View Article and Find Full Text PDFInt J Surg
January 2025
Department of Colorectal Surgery.
Objective: To explore the safety and efficacy of neoadjuvant chemoradiotherapy (nCRT) combined with a PD-1 antibody in improving complete clinical response (cCR) and organ preservation in patients with ultra-low rectal cancer.
Methods: This was a prospective phase II, single-arm, open-label trial. Patients with confirmed pMMR status T1-3aN0-1M0 retcal adenocarcinoma were included.
Rep Pract Oncol Radiother
December 2024
Brachytherapy Department, Greater Poland Cancer Centre, Poznan, Poland.
Rep Pract Oncol Radiother
December 2024
Department of Biomedical Physics, Faculty of Physics, Adam Mickiewicz University, Poznań, Poland.
Background: The purpose of this study is to determine the effect of the type of I-125 radioactive source on dose distribution in the planning process of ultra-low dose rate (uLDR) prostate brachytherapy.
Material And Methods: 7 patients who had undergone brachytherapy in our center were included in the study. Dose in five geometrical points were analyzed for 12 types of implants that are available on the market.
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