Cumulative Effective Dose and Cancer Risk of Pediatric Population in Repetitive Whole-Body Scan Using Dual-Energy X-Ray Absorptiometry

2019 ◽  
Vol 22 (1) ◽  
pp. 52-58 ◽  
Author(s):  
Martin Law ◽  
Wang-Kei Ma ◽  
Eva Chan ◽  
Candy Mui ◽  
Vivian Ma ◽  
...  
Keyword(s):  
Cancer Risk ◽  
Effective Dose ◽  
Pediatric Population ◽  
Dual Energy ◽  
Whole Body ◽  
Whole Body Scan ◽  
Body Scan ◽  
X Ray ◽  
Cumulative Effective Dose

Techniques for Undertaking Dual-Energy X-Ray Absorptiometry Whole-Body Scans to Estimate Body Composition in Tall and/or Broad Subjects

2012 ◽  
Vol 22 (5) ◽  
pp. 313-322 ◽  
Author(s):  
Alisa Nana ◽  
Gary J. Slater ◽  
Will G. Hopkins ◽  
Louise M. Burke
Keyword(s):  
Body Composition ◽  
Dual Energy ◽  
The Body ◽  
Whole Body ◽  
Whole Body Scan ◽  
Body Scan ◽  
Physically Active ◽  
X Ray ◽  
Scanning Area ◽  
Dxa Scans

Dual-energy X-ray absorptiometry (DXA) is becoming a popular tool to measure body composition, owing to its ease of operation and comprehensive analysis. However, some people, especially athletes, are taller and/or broader than the active scanning area of the DXA bed and must be scanned in sections. The aim of this study was to investigate the reliability of DXA measures of whole-body composition summed from 2 or 3 partial scans. Physically active young adults (15 women, 15 men) underwent 1 whole-body and 4 partial DXA scans in a single testing session under standardized conditions. The partial scanning areas were head, whole body from the bottom of the chin down, and right and left sides of the body. Body-composition estimates from whole body were compared with estimates from summed partial scans to simulate different techniques to accommodate tall and/or broad subjects relative to the whole-body scan. Magnitudes of differences in the estimates were assessed by standardization. In simulating tall subjects, summation of partial scans that included the head scan overestimated whole-body composition by ~3 kg of lean mass and ~1 kg of fat mass, with substantial technical error of measurement. In simulating broad subjects, summation of right and left body scans produced no substantial differences in body composition than those of the whole-body scan. Summing partial DXA scans provides accurate body-composition estimates for broad subjects, but other strategies are needed to accommodate tall subjects.

scholarly journals Creatine (methyl-d3) dilution in urine for estimation of total body skeletal muscle mass: accuracy and variability vs. MRI and DXA

2018 ◽  
Vol 124 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Richard V. Clark ◽  
Ann C. Walker ◽  
Ram R. Miller ◽  
Robin L. O’Connor-Semmes ◽  
Eric Ravussin ◽  
...  
Keyword(s):  
Muscle Mass ◽  
Dual Energy ◽  
Intraindividual Variability ◽  
Whole Body ◽  
Dilution Method ◽  
X Ray ◽  
Spot Urine ◽  
Spot Urine Sample ◽  
Liquid Chromatography Tandem Mass ◽  
Total Body

A noninvasive method to estimate muscle mass based on creatine ( methyl-d3) (D3-creatine) dilution using fasting morning urine was evaluated for accuracy and variability over a 3- to 4-mo period. Healthy older (67- to 80-yr-old) subjects ( n = 14) with muscle wasting secondary to aging and four patients with chronic disease (58–76 yr old) fasted overnight and then received an oral 30-mg dose of D3-creatine at 8 AM ( day 1). Urine was collected during 4 h of continued fasting and then at consecutive 4- to 8-h intervals through day 5. Assessment was repeated 3–4 mo later in 13 healthy subjects and 1 patient with congestive heart failure. Deuterated and unlabeled creatine and creatinine were measured using liquid chromatography–tandem mass spectrometry. Total body creatine pool size and muscle mass were calculated from D3-creatinine enrichment in urine. Muscle mass was also measured by whole body MRI and 24-h urine creatinine, and lean body mass (LBM) was measured by dual-energy X-ray absorptiometry (DXA). D3-creatinine urinary enrichment from day 5 provided muscle mass estimates that correlated with MRI for all subjects ( r = 0.88, P < 0.0001), with less bias [difference from MRI = −3.00 ± 2.75 (SD) kg] than total LBM assessment by DXA, which overestimated muscle mass vs. MRI (+22.5 ± 3.7 kg). However, intraindividual variability was high with the D3-creatine dilution method, with intrasubject SD for estimated muscle mass of 2.5 kg vs. MRI (0.5 kg) and DXA (0.8 kg). This study supports further clinical validation of the D3-creatine method for estimating muscle mass. NEW & NOTEWORTHY Measurement of creatine ( methyl-d3) (D3-creatine) and D3-creatinine excretion in fasted morning urine samples may be a simple, less costly alternative to MRI or dual-energy X-ray absorptiometry (DXA) to calculate total body muscle mass. The D3-creatine enrichment method provides estimates of muscle mass that correlate well with MRI, and with less bias than DXA. However, intraindividual variability is high with the D3-creatine method. Studies to refine the spot urine sample method for estimation of muscle mass may be warranted.

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