What type of measurements does Quantitative Computed Tomography (QCT) provide?

• A. Areal measurements
• B. Volumetric measurements
• C. Linear measurements
• D. Microstructural measurements

Answer: (B)

Quantitative Computed Tomography (QCT) is specialized imaging that provides volumetric measurements of bone density, distinguishing it from other modalities like dual-energy X-ray absorptiometry (DXA), which provides areal measurements. QCT assesses the volume of bone rather than just a two-dimensional projection, enabling a more accurate evaluation of bone mineral density (BMD) by calculating the total volume and mineral content within that volume. This ability allows for better assessment of bone quality and strength, providing valuable information in diagnosing conditions such as osteoporosis.

In contrast, areal measurements reflect only the surface area and do not account for variations in thickness or the three-dimensional structure of bone. Linear measurements focus on a single dimension rather than the volumetric aspects. Microstructural measurements delve into the microscopic architecture of bone but are not typically generated by QCT in the way that volumetric data is. Thus, the correct answer highlights the unique capability of QCT in providing a comprehensive understanding of bone density through volumetric analysis.