J Bone Metab.  2017 May;24(2):105-109. 10.11005/jbm.2017.24.2.105.

Measurement Uncertainty in Spine Bone Mineral Density by Dual Energy X-ray Absorptiometry

• Park AJ
• Yoo JI
• Choi JH
• Chae KS
• Kim CG
• Kim DS

• KMID: 2379992
• DOI: http://doi.org/10.11005/jbm.2017.24.2.105

Abstract

BACKGROUND
The purpose of this study was to calculate the measurement uncertainty of the process of bone mineral density (BMD) analysis using dual energy X-ray absorptiometry with traceability.
METHODS
Between March 2015 and October 2016, among healthy participants in their 20s and 30s, the study included those who had not taken calcium, vitamin D supplements and steroids and were without a history of osteoporosis, osteopenia and diseases related to osteoporosis. Relational expression of the model was established based on Guide to the Expression of Uncertainty in Measurements and Eurachem and the uncertainty from each factor was evaluated.
RESULTS
The combined standard uncertainty was 0.015, while the expanded uncertainty was 0.0298. The factor-specific standard uncertainties that occurred in the process of measuring BMD were 0.72% for the calibration curve, 0.9% for the internal quality control (IQC) using Aluminum Spine Phantom, 0.58% for European Spine Phantom (ESP), and 0.9% for the inspector precision (IP).
CONCLUSIONS
The combined standard uncertainty of the spine BMD corrected with ESP was 0.015 when measured at one time and targeting one participant. The uncertainties of the accuracy of the IQC and the IP were higher than that of the other factors. Therefore, there will be a need for establishment of protocols to lower these uncertainties.

Keyword

Absorptiometry photon; Bone density; Lumbar vertebrae; Uncertainty

MeSH Terms

Absorptiometry, Photon*
Aluminum
Bone Density*
Bone Diseases, Metabolic
Calcium
Calibration
Healthy Volunteers
Lumbar Vertebrae
Osteoporosis
Quality Control
Spine*
Steroids
Uncertainty*
Vitamin D
Aluminum
Calcium
Steroids
Vitamin D

Figure

• 

  Fig. 1 Fish bone diagram of uncertainty sources in bone mineral density measurement. ESP, European Spine Phantom; IQC, internal quality control.

• 

  Fig. 2 Process of measurement uncertainty evaluation. Cal, calibration curve; ESP, European Spine Phantom; IQC, internal quality control; n, resolution; IP, inspector precision; Uc, standard uncertainty of calibration curve.

• 

  Fig. 3 (A) Calibration curve and (B) bias were measured between the assigned value of European Spine Phantom and the indicated value of equipment. BMD, bone mineral density; Sxx, residual sum of squares of standard reference.

Reference

1. Goodwin PN. Methodologies for the measurement of bone density and their precision and accuracy. Semin Nucl Med. 1987; 17:293–304.

2. Mussmann B, Overgaard S, Torfing T, et al. Agreement and precision of periprosthetic bone density measurements in micro-CT, single and dual energy CT. J Orthop Res. 2016; DOI: 10.1002/jor.23417.

3. Utkualp N, Ercan I. Anthropometric measurements usage in medical sciences. Biomed Res Int. 2015; 2015:404261.

4. Katusiime B, Corlett S, Reeve J, et al. Measuring medicine-related experiences from the patient perspective: a systematic review. Patient Relat Outcome Meas. 2016; 7:157–171.

5. Park AJ, Choi JH, Kang H, et al. Result of proficiency test and comparison of accuracy using a european spine phantom among the three bone densitometries. J Bone Metab. 2015; 22:45–49.

6. Ozdemir A, Uçar M. Standardization of spine and hip BMD measurements in different DXA devices. Eur J Radiol. 2007; 62:423–426.

7. The International Society for Clinical Densitometry. Official positions. 2012. cited by 2016 December 13. Available from: http://www.iscd.org/official-positions/official-positions/.

8. Theodorsson E. Uncertainty in measurement and total error: tools for coping with diagnostic uncertainty. Clin Lab Med. 2017; 37:15–34.

9. Farrance I, Frenkel R. Uncertainty of measurement: a review of the rules for calculating uncertainty components through functional relationships. Clin Biochem Rev. 2012; 33:49–75.

10. Genant HK, Grampp S, Glüer CC, et al. Universal standardization for dual x-ray absorptiometry: patient and phantom cross-calibration results. J Bone Miner Res. 1994; 9:1503–1514.

11. Kalender WA, Felsenberg D, Genant HK, et al. The European spine phantom-a tool for standardization and quality control in spinal bone mineral measurements by DXA and QCT. Eur J Radiol. 1995; 20:83–92.

12. Lenchik L, Kiebzak GM, Blunt BA. What is the role of serial bone mineral density measurements in patient management? J Clin Densitom. 2002; 5:Suppl. S29–S38.

13. Kolta S, Ravaud P, Fechtenbaum J, et al. Accuracy and precision of 62 bone densitometers using a European Spine Phantom. Osteoporos Int. 1999; 10:14–19.

14. Cox M, Harris P, Siebert BR. Evaluation of measurement uncertainty based on the propagation of distributions using Monte Carlo simulation. Meas Tech. 2003; 46:824–833.

15. Welch BL. The generalisation of student's problems when several different population variances are involved. Biometrika. 1947; 34:28–35.

16. Satterthwaite FE. An approximate distribution of estimates of variance components. Biometrics. 1946; 2:110–114.