The Alara Metriscan phalangeal densitometer: evaluation and triage thresholds

Area of Science:

• Radiological imaging
• Bone densitometry
• Osteoporosis diagnostics

Background:

• Compact digital radiographic absorptiometry devices offer potential for peripheral bone density assessment.
• The Metriscan device measures phalangeal bone mineral density (BMD(au)) using the middle three digits.
• Establishing performance and clinical utility is crucial for new diagnostic tools.

Purpose of the Study:

• To evaluate the utility and performance of the Metriscan device for phalangeal bone mineral density measurement.
• To establish triage thresholds for osteoporosis management based on National Osteoporosis Society guidelines.
• To assess the Metriscan's suitability for post-menopausal women in a community setting.

Main Methods:

• 170 white female participants (55-70 years) underwent Metriscan scans of both hands.
• Participants were categorized based on existing hip or spine dual X-ray absorptiometry (DXA) results.
• In vitro and in vivo precision studies were conducted, alongside phantom-based assessments.

Main Results:

• In vitro precision was excellent (0.17-0.31% CV).
• In vivo short-term precision was 1.42% overall, with variations between non-osteoporotic (1.30%) and osteoporotic (2.23%) groups.
• Established triage thresholds for the dominant hand were 55.02 BMD(au) (reassurance/referral) and 48.73 BMD(au) (referral/treatment).

Conclusions:

• The Metriscan demonstrates good in vitro and acceptable in vivo precision for phalangeal bone mineral density.
• The device is suitable for community-based triage of post-menopausal women, complementing axial bone mineral density assessments.
• The dominant hand showed slightly superior performance for triage purposes.