Quantitative Ultrasound of Bone

Quantitative Ultrasound of Bone

LASA filenames:
LASACo31
LASAGo31

Contact: Natasja van Schoor

Background
Osteoporosis is a disease of the skeleton characterised by low bone mineral density (BMD) and a micro architectural deterioration of bone tissue that results in an increased susceptibility to fractures (1). BMD, measured with dual-energy X-ray absorptiometry (DXA), is regarded as the most important parameter for the assessment of osteoporosis and fracture risk (2-4). Since a few years, quantitative ultrasound (QUS) measurements have generated widespread interest. QUS offers several advantages over DXA, since the apparatus is free of ionising radiation, relatively inexpensive and simple to apply (5). The great variety of different QUS devices available makes it possible to perform QUS measurements at several skeletal sites such as the calcaneus (heel bone), ulna, patella, phalanges (fingers) and tibia (6).

QUS measures the speed at which sound propagates through or along bone (SOS) or the pattern of attenuation of a wide range of ultrasonic frequencies in bone (BUA). It has been postulated that QUS may reflect more than bone density alone. Qualitative aspects of bone, such as elasticity and micro architectural characteristics, could also be assessed by QUS (7-9).

Measurement instruments in LASA

Subjects: subsamples
During the medical interview of the C-cycle, participants were invited to visit the VU University Medical Center (VUmc) or a health care center in the neighbourhood, where the QUS measurements were performed (n=1346). QUS measurements were also performed at the right tibia in sex-stratified subsample (n=127) of respondents who visited the VUmc.

QUS measurements were also performed at the G-cycle, in the second cohort only as a side study. A subsample of the EPOSA participants (see EPOSA website) were invited to take part in the BBMRI study in which, among others, QUS measurements were performed. In addition to the EPOSA participants, a subsample of the remaining LASA participants was invited for the BBMRI study (total N = 496).

QUS measurements of the calcaneus
QUS measurements were performed at the calcaneus with the CUBA Clinical instrument (McCue Ultrasonics, Winchester, UK) at the C-cycle. The ultrasound system consists of two transducers (emitting and receiving) faced with silicone rubber coupling pads. These are placed in direct contact on either side of the heel using a coupling gel. BUA (dB/MHz) and SOS (m/s) were measured twice in both the right and left calcaneus. The feet were repositioned after the first measurement. The coefficient of variation (CV), calculated in 20 healthy volunteers measured on five occasions consecutively within 1h, was 3.4% for BUA and 1.3% for SOS (10). At the G-cycle the measurements were performed using the Hologic Sahara densitometer (Hologic Inc., USA). At this cycle, if the two measurements at the same foot differed for more than 10 percent (BUA values), a third measurement was performed. The feet were repositioned after each measurement.

QUS measurements of the tibia
QUS measurements were performed at the right tibia using the Sound scan 2000 instrument (Myriad Ultrasound System, Rehovot, Israel) in the C-cycle. Subjects were supine with the lower leg at the right side exposed. The midpoint of the tibia was marked which is halfway between the distal apex of the patella and the medial malleolus, and a probe was placed on the skin at this point. Ultrasonic coupling gel was used to facilitate the propagation of sound between the probe and the skin. The speed of sound through the tibia was calculated from the propagation time and distance between a sound-emitting sensor at one side of the probe and a receiving sensor at the other side. By moving the probe back and forth across the tibial plane, a minimum of 150-200 velocity reading was obtained. The average of the five highest readings was calculated to render the cortical tibial ultrasound velocity (11) The CV, calculated in 16 healthy LASA subjects, was 0.4% and the standardised CV (sCV) was 4.4% (12).

Questionnaires
Not applicable for this topic.

Variable information
It is recommended that mean values are calculated before analysing the data. Mean values can be calculated for the right and left side separately, or for both sides together.

In the G-cycle, in case of three measurements, it is necessary to calculate mean values by only using the two values which were approximately equal and ignoring the third aberrant one.

Availability of information per wave 1

BCDE
2B*		FGH

3B*		MB*IJK
QUS Calcaneus

-N=1346----N=496------
QUS Tibia

-N=127-----------

1 More information about the LASA data collection waves is available here.

* 2B=baseline second cohort;
3B=baseline third cohort;
MB=migrants: baseline first cohort

Previous use in LASA


References

  1. Anonymous. Who are candidates for prevention and treatment for osteoporosis? Osteoporos Int 1997; 7: 1-6.
  2. Melton III LJ, Eddy DM, Johnston CC. Screening for osteoporosis. Ann Intern Med 1990; 112: 516-28.
  3. Cummings SR, Black DM, Nevitt MC et al. Bone density at various sites for prediction of hip fractures. Lancet 1993; 341: 72-5.
  4. World Health Organisation. Assessment of fracture risk and its application to screening for postmenopausal osteoporosis. WHO technical report series 843. Geneva: World Health Organisation, 1994: 1-129.
  5. Kaufman JJ, Einhorn TA. Ultrasound assessment of bone. J Bone Miner Res 1993; 8: 17-25.
  6. Hans D, Schott AM, Meunier PJ. Ultrasonic assessment of bone: a review. Eur J Med 1993; 2: 157-163.
  7. Tavakoli MD, Evans JA. Dependence of the velocity and attenuation in bone on the mineral content. Phys Med Biol 1991; 36: 1529-37.
  8. Glüer CC, Wu CY, Genant HK. Broadband ultrasound attenuation signals depend on trabecular orientation: an in-vitro study. Osteoporos Int 1993; 3: 185-91.
  9. Njeh CF. The dependence of ultrasound velocity and attenuation on the material properties of cancellous bone. (PhD thesis), Sheffield Hallam University, UK, 1995.
  10. Graafmans WC, van Lingen A, Ooms ME, Bezemer PD, Lips P. Ultrasound measurements in the calcaneus: precision and its relation with bone mineral density of the heel, hip and lumbar spine. Bone 1996; 19: 97-100.
  11. Foldes AJ, Rimon A, Keinan DD, Popovtzer MM. Quantitative ultrasound of the tibia: a novel approach for assessment of bone status. Bone 1995; 17: 363-367.
  12. Tromp AM, Smit JH, Deeg DJH, Lips P. Quantitative ultrasound measurements of the tibia and calcaneus in comparison with DXA measurements at various skeletal sites. Osteoporosis Int 1999; 9: 230-235.


Date of last update: April 6, 2020