DXA: Technical aspects and application

Bazzocchi, Alberto; Ponti, Federico; Albisinni, Ugo; Battista, Giuseppe; Guglielmi, Giuseppe

doi:10.1016/j.ejrad.2016.04.004

Cited by 182 publications

(192 citation statements)

References 56 publications

(94 reference statements)

Supporting

Mentioning

159

Contrasting

Unclassified

Order By: Relevance

“…Example of dual-energy x-ray absorptiometry total body scan with regions of interest defined [76] . scan; (B) cross-sectional scan obtained at the lower leg (66% tibia) with muscle borders manually drawn [77] . diagram of the 26-week RCT presented within this thesis (adapted from Owen et al [304] ; Appendix A).…”

Section: Discussionmentioning

confidence: 99%

“…Computed tomography (CT) and magnetic resonance imaging (MRI) are recognised as the gold standard for acquiring measures of muscle with high accuracy [40,77,111,112] . However, these techniques are limited in the clinical and research setting due to the high costs of scan acquisition and data processing, complications with claustrophobic and severely obese individuals (BMI ≥ 40 kg/m 2 ), and in the case of CT, high exposure to ionising radiation [76,111] .…”

Section: Lean Mass and Muscle Cross-sectional Areamentioning

confidence: 99%

“…• Visceral fat mass: the fat mass located within the abdominal cavity, between various organs (also known as intra-abdominal fat mass) [77] .…”

mentioning

confidence: 99%

“…• Muscle cross-sectional area (CSA): a volumetric assessment of a slice of tissue used as a measure of regional muscle mass [77] .…”

mentioning

confidence: 99%

See 3 more Smart Citations

Muscle, fat and performance during androgen deprivation for prostate cancer

Owen¹

2018

Preprint

View full text Add to dashboard Cite

Introduction: Prostate cancer (PCa) is one of the most frequently diagnosed male cancers worldwide. One treatment, androgen deprivation therapy (ADT), is often accompanied with a myriad of adverse effects, including those that negatively impact muscle, fat and performance outcomes. Therefore, ADT-treated men may be living longer, but are at risk of both age- and treatment-related complications. The overall aim of this thesis was to quantify outcomes of muscle, fat and performance in men treated with ADT when compared to PCa (men diagnosed with PCa, not treated with ADT) and healthy controls (men not diagnosed with PCa), and assess the feasibility of implementing a multi-component exercise program combined with protein, calcium and vitamin D supplementation (Ex+ProCaD) compared to usual care in ADT-treated men. Methods: This thesis presents two studies that form part of a larger 52-week randomised controlled trial (RCT), which examined the efficacy of Ex+ProCaD compared to usual care in men treated with ADT for PCa. The first study presented was a nested cross-sectional study performed parallel to the baseline assessment of the RCT and examined differences in muscle, fat and performance outcomes between men treated with ADT when compared to PCa and healthy controls. The second study presented examined the feasibility of implementing the first 26 weeks of the RCT. Results: The cross-sectional study showed that height, weight, body mass index and diet were similar between the three groups, but ADT-treated men were four years older and tended to be less physically active (23-30%; P=0.054). After adjusting for age and physical activity, total body fat mass was 3.3-5.0 kg (P < 0.05) greater in men treated with ADT compared to PCa controls, but there was no difference in total body and regional lean mass. When adiposity was considered, ADT-treated men had 10-12% (P < 0.05) lower appendicular lean mass adjusted for body mass index and 5.6-6.4% (P < 0.05) lower forearm percent muscle cross-sectional area compared to controls. Absolute muscle strength was similar between groups, but when expressed relative to body weight, men treated with ADT had 13-21% (P < 0.05) lower muscle strength compared to controls. Whilst only two ADT-treated men had sarcopenia, these men had a higher proportion (P < 0.001) of pre-sarcopenia when appendicular lean mass was adjusted for body mass index (42%) compared to PCa (15%) and healthy (7%) controls. Men treated with ADT had 15-36% (P < 0.05) greater storage of fat within subcutaneous depots when compared to controls, whereas visceral and intermuscular fat was similar. The majority of subcutaneous fat depots (excluding android region) were shown to be positively associated with ADT duration (P < 0.05). Forearm muscle density was shown to negatively correlate with ADT duration (P < 0.05). The RCT had a high participant retention rate (96%). Adherence was high for the supplement (mean, 92-93%) and modest for the exercise program (mean, 60%). A relatively high proportion (81%) of men in the intervention group reported an adverse event, although only 16% were confirmed to be related to the intervention and the vast majority (97%) were determined to be mild or moderate in terms of severity. Across the ten separate recruitment pathways considered, clinician referral (43%) and PCa support groups (29%) yielded the greatest proportion of enrolled participants. A total of 149 potential participants were screened, which resulted in 42 participants at the time of write up for this thesis. Among the first 28 participants to complete the 26-week intervention, 21-50% were unable to complete at least one measure of muscle strength due to pre-existing comorbidities. Data from the initial 28 participants tended to show that when compared to usual care, Ex+ProCaD led to net improvements in lean mass (0.2-1.4 kg), fat mass (-0.1 to -0.9 kg), muscle strength (8.0-19%), functional muscle power (8.6%) and functional capacity (12-14%). Conclusions: The following key themes emerged from this thesis and may be used to guide clinical practice guidelines and future research: 1) Men treated with ADT for PCa had greater amounts of fat when compared to non-ADT counterparts, 2) Current definitions of sarcopenia and sarcopenic obesity were limited in men treated with ADT for PCa, 3) The greater amounts of fat observed in men treated with ADT for PCa tended to be stored in subcutaneous depots and supersede age-related plateaus/losses, 4) The recruitment of men treated with ADT for PCa into a lifestyle intervention was challenging, and 5) Men treated with ADT for PCa tended to respond positively to a multi-modal exercise training combined with multi-nutrient supplementation.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Lean Mass and Muscle Cross-sectional Areamentioning

confidence: 99%

See 2 more Smart Citations

Muscle, fat and performance during androgen deprivation for prostate cancer

Owen¹

2018

Preprint

View full text Add to dashboard Cite

show abstract

“…The role of DXA is central in the study of body composition (BC) thanks to its ability to differentiate FM, non-bone lean mass (LM) and BMC at both the regional and the whole-body level ( Figure 2) (49)(50)(51)(52)(53)(54)(55)(56)(57)(58)(59)(60). DXA relies on the use of two X-ray beams of different energy; the measurement of the "R value" is calculated as the ratio between the degree of attenuation of the lower energy and the higher energy beam.…”

Section: Dxamentioning

confidence: 99%

Quantitative imaging techniques for the assessment of osteoporosis and sarcopenia

Guerri

Mercatelli

Gómez

et al. 2018

Quant. Imaging Med. Surg.

Self Cite

106

View full text Add to dashboard Cite

Bone and muscle are two deeply interconnected organs and a strong relationship between them exists in their development and maintenance. The peak of both bone and muscle mass is achieved in early adulthood, followed by a progressive decline after the age of 40. The increase in life expectancy in developed countries resulted in an increase of degenerative diseases affecting the musculoskeletal system. Osteoporosis and sarcopenia represent a major cause of morbidity and mortality in the elderly population and are associated with a significant increase in healthcare costs. Several imaging techniques are currently available for the non-invasive investigation of bone and muscle mass and quality. Conventional radiology, dual energy X-ray absorptiometry (DXA), computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound often play a complementary role in the study of osteoporosis and sarcopenia, depicting different aspects of the same pathology. This paper presents the different imaging modalities currently used for the investigation of bone and muscle mass and quality in osteoporosis and sarcopenia with special emphasis on the clinical applications and limitations of each technique and with the intent to provide interesting insights into recent advances in the field of conventional imaging, novel high-resolution techniques and fracture risk.

show abstract

Understanding entrance‐air‐kerma as a quality‐control metric for dual‐energy x‐ray absorptiometry

Thomas

Jimenez

Fahrenholtz

et al. 2022

J Applied Clin Med Phys

View full text Add to dashboard Cite

The low exposures, unique x-ray beam geometry, and scanning design in dual-energy x-ray absorptiometry (DXA) make measurement and quality-control strategies different from traditional x-ray equipment. This study examines the dependence of measured entrance-air-kerma (EAK) on both dose sensor type and scan length. The feasibility of using EAK to compare scanner output between different scan modes, individual scanners, and scanner platforms was also established. Finally, the congruence between measured and vendor-reported EAK was analyzed. Methods: Four Hologic DXA scanners at two institutions and all four available scan modes were tested. EAK was measured directly by three types of Radcal dose sensors: 60-cc pancake ion-chamber (IC), 180-cc pancake IC, and solid-state detector. The coefficient of variation (COV) was used to assess the dependence of EAK on scan length. Variations in EAK between the types of dose sensors as well as measured versus vendor-reported values were evaluated using Bland-Altman analysis: mean ±95% prediction interval (PI): 1.96σ. Results: Dose sensor variations in EAK were minimal, with a −3.5 ± 3.5% (mean ±95% PI) percent difference between the two sizes of IC's. The solidstate detector produced highly similar measurements to the 180-cc IC. These small differences were consistent across all scanners and all scan modes tested. Neither measured nor vendor-reported EAK values were found to show relevant dependence on scan length, with all COV values ≤4%. Differences between measured and reported EAK were higher at −6 ± 48%. Likely errors in vendor-reported EAK calculations were also identified. Conclusion:It is feasible to quantify DXA scanner stability using EAK as a quality-control metric with a variety of solid-state and IC dose sensors, and the scan length used is not critical. Although vendor-reported EAK was consistent among scanners of the same platform, measured EAK varied significantly from scanner to scanner. As a result, measured and reported EAK may not always be comparable.

show abstract

DXA: Technical aspects and application

Cited by 182 publications

References 56 publications

Muscle, fat and performance during androgen deprivation for prostate cancer

Muscle, fat and performance during androgen deprivation for prostate cancer

Quantitative imaging techniques for the assessment of osteoporosis and sarcopenia

Understanding entrance‐air‐kerma as a quality‐control metric for dual‐energy x‐ray absorptiometry

Contact Info

Product

Resources

About