A pilot study of patient-specific cardiovascular MDCT dose maps and their utility in estimating patient-specific organ and effective doses in obese patients

Autor: Nancy A. Obuchowski, Jennifer A. Bullen, Jens Wiegert, Sandra S. Halliburton, Carla M. Thompson, Kavitha Yaddanapudi, Jeffrey H. Yanof
Rok vydání: 2015
Předmět:
Patient-Specific Modeling
medicine.medical_specialty
Computed Tomography Angiography
Dose metrics
Aorta
Thoracic
Pilot Projects
Coronary Angiography
Radiation Dosage
Effective dose (radiation)
Aortography
030218 nuclear medicine & medical imaging
Body Mass Index
03 medical and health sciences
0302 clinical medicine
Predictive Value of Tests
medicine.artery
Multidetector Computed Tomography
medicine
Thoracic aorta
Humans
Radiology
Nuclear Medicine and imaging
Obesity
Retrospective Studies
business.industry
Phantoms
Imaging
Organ Size
Phlebography
Patient specific
Coronary Vessels
Coronary arteries
medicine.anatomical_structure
Cardiovascular Diseases
Pulmonary Veins
030220 oncology & carcinogenesis
Radiology
Cardiology and Cardiovascular Medicine
Tissue composition
Nuclear medicine
business
Body mass index
Monte Carlo Method
Zdroj: Journal of cardiovascular computed tomography. 10(3)
ISSN: 1876-861X
Popis: 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 (E DoseMap ) to doses determined from standard DLP conversion (E DLP ) 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. E DoseMap was computed as a weighted sum of organ doses multiplied by tissue-weighting factors. Results E DLP (mean ± SD, 5.7 ± 3.3 mSv) was larger than E DoseMap (3.4 ± 2.4 mSv) (difference = 2.3; P 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.
Databáze: OpenAIRE
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