The DXL Calscan heel densitometer: evaluation and diagnostic thresholds

Area of Science:

• Medical Imaging
• Osteoporosis Management
• Bone Densitometry

Background:

• Dual-energy X-ray absorptiometry (DXA) is a standard for bone mineral density (BMD) assessment.
• Accurate BMD measurement is crucial for diagnosing and managing osteoporosis, particularly in post-menopausal women.
• Existing peripheral densitometry methods can benefit from enhanced accuracy and ease of use.

Purpose of the Study:

• To evaluate the DXL Calscan, a novel fan-beam DXA device with integrated laser heel thickness measurement.
• To assess the in vitro and in vivo performance and utility of the DXL Calscan for heel BMD.
• To establish triage thresholds for osteoporosis management based on UK guidelines.

Main Methods:

• Evaluated DXL Calscan's utility, in vitro precision (phantom repositioning), and in vivo precision (duplicate scans).
• Assessed device stability across time and temperatures, and measured effective radiation dose.
• Scanned 140 white females (70 osteoporotic, 70 non-osteoporotic) using axial DXA for classification, then DXL Calscan of both heels to establish triage thresholds.

Main Results:

• DXL Calscan demonstrated excellent in vitro precision (0.75% short-term, 0.73% long-term) and good in vivo precision (1.19%).
• The device is convenient, easy to use, stable, and delivers a low radiation dose (<0.1 microSv).
• Established triage thresholds for non-dominant and dominant heels, with the non-dominant heel showing slight superiority for triage.

Conclusions:

• The DXL Calscan is a suitable device for managing post-menopausal osteoporosis when operated by trained personnel in at-risk populations.
• Its combination of DXA and laser measurement offers improved accuracy for heel BMD assessment.
• The established triage thresholds aid in classifying patients for reassurance, referral, or treatment.