Pediatric radiation dose and risk from bone density measurements using a GE Lunar Prodigy scanner

Levels of free thyroxine are higher in displaced pediatric supracondylar humerus fractures compared with non‑displaced fractures

Relationships between bone metabolic biomarkers and fracture displacement have been reported in the elderly. However, factors related to bone metabolism that predict fracture displacement remain unclear in children. The present study investigated bone metabolic biomarkers associated with the displacement of pediatric supracondylar humerus fractures. A total of 19 patients (7 male and 12 female patients; mean age, 6.3 years) with pediatric supracondylar humerus fractures who underwent surgical treatment at Juntendo University Hospital (Tokyo, Japan) between December 2020 and September 2022 were included. They were divided into two groups according to the Gartland classification: 14 type II patients (6 male and 8 female patients; mean age, 6.3±3.0 years) and 5 type III patients (1 male and 4 female patients; mean age, 6.4±4.0 years). The following bone metabolic biomarkers were examined: 25-hydroxyvitamin D [25(OH)D], intact parathyroid hormone (iPTH), calcium, phosphate, thyroid-stimulating hormone, free triiodothyronine and free thyroxine (FT4). These markers were also compared between the two groups. A total of 16 out of 19 patients (84%) had insufficient serum 25(OH)D levels. Although iPTH levels were elevated, other bone metabolic biomarkers were within normal ranges. When the serum levels of bone metabolic biomarkers were compared, FT4 levels were significantly higher in type III patients than in type II patients (P=0.009). No significant differences were observed in other bone metabolic biomarkers between the two groups. The present results suggest that high FT4 levels are associated with the displacement of pediatric supracondylar humerus fractures.

Establishing national diagnostic reference levels in radiography, mammography, and dual-energy x-ray absorptiometry services in Ireland and comparing these with European diagnostic reference levels

OBJECTIVES

The aim of this work was to establish national diagnostic reference levels (DRLs) in Ireland and compare these to existing European DRLs where available. This work surveyed all radiological facilities providing radiography, mammography, and dual-energy x-ray absorptiometry (DXA) services in Ireland.

METHODS

A list of common procedures and clinical tasks was established. A national database of service providers was used to identify the appropriate medical radiological facilities providing these services. These facilities were issued with an online survey. National DRLs were set as the 75th percentile of the distribution of median values obtained. A national median dose was also established. The broad categorisation of equipment type was also considered. Where differences between DRLs established using different detector types were deemed statistically significant, equipment-specific national DRLs were established.

RESULTS

National DRLs were established for 12 adult radiography projections. Equipment-specific (computed radiography and digital radiography) adult DRLs were established for four radiography projections. Paediatric DRLs were established for 11 radiography projections, including two based on clinical indications, for a range of paediatric weight categories. National DRLs were established for unilateral two-view mammography and breast tomosynthesis as well as for four DXA clinical indications and projections. All but one Irish DRL figure was found to be below or equal to European data.

CONCLUSIONS

This work provided a unique opportunity to establish national DRLs based on census data for a range of procedures and clinical tasks across radiography, mammography and DXA and compare these with European levels.

CLINICAL RELEVANCE STATEMENT

This work established national diagnostic reference levels (DRLs) based on census data for a range of procedures and clinical tasks across radiography, mammography and dual-energy x-ray absorptiometry. The establishment of national DRLs is an essential component in the optimisation of patient radiation dose.

KEY POINTS

• Diagnostic reference levels are easily measured quantities intended for use as an aid to optimise patient dose and to identify when levels of patient dose are unusually high. • Data from all medical radiological facilities in Ireland was obtained to establish national diagnostic reference level (DRL) values and national median dose values in radiography, x-ray breast imaging and dual-energy x-ray absorptiometry (DXA) scanning and these were compared to existing European DRLs where available. • National DRL values were established for the first time in breast tomosynthesis, DXA scanning, and paediatric radiography.

Plasma Metabolomics Reveals β-Glucan Improves Muscle Strength and Exercise Capacity in Athletes

The present study aimed to assess the changes in muscle strength and plasma metabolites in athletes with β-glucan supplementation. A total of 29 athletes who met the inclusion criteria were recruited for this study (ChiCTR2200058091) and were randomly divided into a placebo group (n = 14) and β-glucan group (n = 15). During the trial, the experimental group received β-glucan supplementation (2 g/d β-glucan) for 4 weeks and the control group received an equal dose of placebo supplementation (0 g/d β-glucan), with both groups maintaining their regular diet and exercise habits during the trial. The athletes’ exercise performance, muscle strength, and plasma metabolome changes were analyzed after 4 weeks of β-glucan supplementation. The results showed a significant increase in mean grip strength (kg), right hand grip strength (kg), left triceps strength (kg), and upper limb muscle mass (kg) in the experimental group after the 4-week intervention compared to the preintervention period (p < 0.05). A comparison of the difference between the two groups after the intervention showed that there were significant differences between the control group and the experimental group in mean grip strength (kg) and right-hand grip strength (kg) (p < 0.05). Athletes in the experimental group showed significant improvements in 1 min double rocking jump (pcs), VO2max (ml/kg-min) (p < 0.05). The β-glucan intake increased the creatine-related pathway metabolites in plasma. Overall, these results suggest that 4 weeks of β-glucan supplementation can improve muscle strength in athletes, with the potential to increase aerobic endurance and enhance immune function, possibly by affecting creatine-related pathways.

Official position of the Brazilian Association of Bone Assessment and Metabolism (ABRASSO) on the evaluation of body composition by densitometry: part I (technical aspects)—general concepts, indications, acquisition, and analysis

Objective

To review the technical aspects of body composition assessment by dual-energy X-ray absorptiometry (DXA) and other methods based on the most recent scientific evidence.

Materials and methods

This Official Position is a result of efforts by the Scientific Committee of the Brazilian Association of Bone Assessment and Metabolism (Associação Brasileira de Avaliação Óssea e Osteometabolismo, ABRASSO) and health care professionals with expertise in body composition assessment who were invited to contribute to the preparation of this document. The authors searched current databases for relevant publications. In this first part of the Official Position, the authors discuss the different methods and parameters used for body composition assessment, general principles of DXA, and aspects of the acquisition and analysis of DXA scans.

Conclusion

Considering aspects of accuracy, precision, cost, duration, and ability to evaluate all three compartments, DXA is considered the gold-standard method for body composition assessment, particularly for the evaluation of fat mass. In order to ensure reliable, adequate, and reproducible DXA reports, great attention is required regarding quality control procedures, preparation, removal of external artifacts, imaging acquisition, and data analysis and interpretation.

Infant body composition assessment in the neonatal intensive care unit (NICU) using air displacement plethysmography: Strategies for implementation into clinical workflow

Nutritional management is integral to infant care in the neonatal intensive care unit (NICU). Recent research on body composition that specifically evaluated fat and fat-free mass has improved our understanding of infant growth and nutritional requirements. The need for body composition monitoring in infants is increasingly recognized as changes in fat mass and fat-free mass associated with early growth can impact clinical outcomes. With the availability of air displacement plethysmography (ADP) as a noninvasive method for assessing infant body composition and published normative gestational age- and sex-specific body composition curves, it is justifiable to integrate this innovation into routine clinical care. Here we describe our experiences in implementing body composition measurement using ADP in routine clinical care in different NICU settings.

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

This study aims to quantitatively evaluate the cumulative effective dose and associated cancer risk of pediatric patients of US and Hong Kong population undergoing repetitive whole-body scans with dual-energy X-ray absorptiometry (DXA) during their diagnosis and follow-up periods. Organ-absorbed doses of pediatric patients undergoing DXA whole-body scan have been computer simulated using patient imaging parameters input to the Monte Carlo software PCXMC. Gender- and age-specific effective doses have been calculated with the simulated organ-absorbed doses using the ICRP-103 approach. The associated radiation-induced cancer risk, expressed as lifetime attributable cancer risk (LAR), has been estimated according to the method introduced in the Biological Effects of Ionizing Radiation VII report. Mathematical fitting for effective dose and for LAR, as a function of age at exposure, has been analytically obtained to quantitatively estimate the cumulated effective dose and LAR for pediatric patients of US and Hong Kong population with repetitive DXA whole-body scan during their follow-up period. The effective dose of a single DXA whole-body scan for patients exposed at the age between 5 and 18 years was calculated as 8.47-17.68 µSv. The corresponding LAR for US and Hong Kong population was between the range of 4.57 × 10^-7 and 7.14 × 10^-7. The cumulative effective dose of DXA whole-body scan for patients exposed annually at age between 5 and 18 years was calculated as 180 µSv for girls and 168 µSv for boys. The corresponding cumulative LAR for US and Hong Kong population was calculated as 3.77 × 10^-6 to 5.48 × 10^-6. Girls would be at a statistically significant higher cumulated cancer risk than boys under the same whole-body DXA protocol (p = 0.03). The probability of cumulative LAR for pediatric populations undergoing annual DXA whole-body scan is regarded as minimal. We demonstrate the use of computer simulation and analytic formulation to quantitatively obtain the cumulated effective dose and cancer risk at any age of exposure, which are useful information for medical personnel to track patient radiation dose and to alleviate patients' parents concern about radiation safety in repetitive whole-body scan using DXA.

Agreement Between Standard Body Composition Methods to Estimate Percentage of Body Fat in Young Male Athletes

PURPOSE

To examine the intermethods agreement of dual-energy X-ray absorptiometry (DXA) and foot-to-foot bioelectrical impedance analysis (BIA) to assess the percentage of body fat (%BF) in young male athletes using air-displacement plethysmography (ADP) as the reference method.

METHODS

Standard measurement protocols were carried out in 104 athletes (40 swimmers, 37 footballers, and 27 cyclists, aged 12-14 y).

RESULTS

Age-adjusted %BF ADP and %BF BIA were significantly higher in swimmers than footballers. ADP correlates better with DXA than with BIA (r = .84 vs r = .60, P < .001). %BF was lower when measured by DXA and BIA than ADP (P < .001), and the bias was higher when comparing ADP versus BIA than ADP versus DXA. The intraclass correlation coefficients between DXA and ADP showed a good to excellent agreement (r = .67-.79), though it was poor when BIA was compared with ADP (r = .26-.49). The ranges of agreement were wider when comparing BIA with ADP than DXA with ADP.

CONCLUSION

DXA and BIA seem to underestimate %BF in young male athletes compared with ADP. Furthermore, the bias significantly increases with %BF in the BIA measurements. At the individual level, BIA and DXA do not seem to predict %BF precisely compared with ADP in young athletic populations.

Effect of a program of short bouts of exercise on bone health in adolescents involved in different sports: the PRO-BONE study protocol

BACKGROUND

Osteoporosis is a skeletal disease associated with high morbidity, mortality and increased economic costs. Early prevention during adolescence appears to be one of the most beneficial practices. Exercise is an effective approach for developing bone mass during puberty, but some sports may have a positive or negative impact on bone mass accrual. Plyometric jump training has been suggested as a type of exercise that can augment bone, but its effects on adolescent bone mass have not been rigorously assessed. The aims of the PRO-BONE study are to: 1) longitudinally assess bone health and its metabolism in adolescents engaged in osteogenic (football), non-osteogenic (cycling and swimming) sports and in a control group, and 2) examine the effect of a 9 month plyometric jump training programme on bone related outcomes in the sport groups.

METHODS/DESIGN

This study will recruit 105 males aged 12-14 years who have participated in sport specific training for at least 3 hours per week during the last 3 years in the following sports groups: football (n = 30), cycling (n = 30) and swimming (n = 30). An age-matched control group (n = 15) that does not engage in these sports more than 3 hours per week will also be recruited. Participants will be measured on 5 occasions: 1) at baseline; 2) after 12 months of sport specific training where each sport group will be randomly allocated into two sub-groups: intervention group (sport + plyometric jump training) and sport group (sport only); 3) exactly after the 9 months of intervention; 4) 6 months following the intervention; 5) 12 months following the intervention. Body composition (dual energy X-ray absorptiometry, air displacement plethysmography and bioelectrical impedance), bone stiffness index (ultrasounds), physical activity (accelerometers), diet (24 h recall questionnaire), pubertal maturation (Tanner stage), physical fitness (cardiorespiratory and muscular), bone turnover markers and vitamin D will be measured at each visit.

DISCUSSION

The PRO-BONE study is designed to investigate the impact of osteogenic and non-osteogenic sports on bone development in adolescent males during puberty, and how a plyometric jump training programme is associated with body composition parameters.

Bone densitometry in children and adolescents

PURPOSE OF REVIEW

Abnormalities in bone health are increasingly recognized in the pediatric population. Although the methodologies for assessing bone mineral density were originally developed for adults, great strides have been made in recent years, improving their applicability to children. Understanding these technologies, their interpretation, utility, and limitations is critical when assessing a child or adolescent with a suspected abnormality in bone mineral density.

RECENT FINDINGS

Improved normative databases that address some of the confounding variables in the growing and maturing child have solidified dual-energy X-ray absorptiometry as the preferred method for the assessment of bone mineral density in children. Consensus statements by expert panels now provide specific guidance to clinicians seeking to evaluate children with fractures or at risk for fractures. Although still primarily a research tool, continued development of quantitative computed tomography applications in pediatrics suggests there may be a complementary role for clinical use in the future.

SUMMARY

In the child or adolescent with a significant fracture history or a potential for fractures because of an underlying cause, clinicians now have guidelines and normative data to better focus their evaluation. Likewise, researchers can use this information to improve clinical trial design and interpretation of results.