Routine Coronary Calcium Scan Can Precisely Measure Vertebral Bone Density Without a Quantitative Calibration Phantom

Area of Science:

• Radiology
• Medical Imaging
• Bone Densitometry

Background:

• Coronary artery calcium scans (CACS) are commonly used for cardiovascular risk assessment.
• Assessing thoracic bone mineral density (BMD) is crucial for diagnosing osteoporosis and predicting fracture risk.
• Quantitative computed tomography (QCT) is a standard method for BMD assessment, but requires calibration phantoms.

Purpose of the Study:

• To evaluate the accuracy and precision of both quantitative computed tomography (QCT) and a phantomless approach for thoracic bone mineral density (BMD) assessment.
• To compare the performance of QCT and phantomless methods when applied to data acquired during coronary artery calcium scans (CACS).

Main Methods:

• A cohort of 513 subjects underwent CACS with a calibration phantom.
• Thoracic spine BMD and calcium hydroxyapatite concentration were measured using both QCT with a phantom and a phantomless technique.
• CT Hounsfield units were recorded for both methods, and accuracy (bias) and precision errors were compared.

Main Results:

• The mean bias from true calcium concentration was 2.9% for QCT and 3.8% for the phantomless method (P < 0.001).
• The bias of thoracic BMD measurements derived from QCT using the phantomless method was 3.8%.
• Both QCT and phantomless methods demonstrated similar precision errors in thoracic BMD assessment.

Conclusions:

• Thoracic bone mineral density (BMD) can be accurately and precisely assessed using both quantitative computed tomography (QCT) and phantomless techniques.
• These methods are applicable during routine coronary artery calcium scans (CACS), offering a potential dual-purpose imaging approach.
• The findings support the integration of BMD assessment into standard CACS protocols.