What unit of measurement is typically used for reporting QCT results?

• A. g/cm cubed
• B. mg/dL
• C. mg/cm squared
• D. g/mL

Answer: (A)

The correct unit of measurement for reporting quantitative computed tomography (QCT) results is grams per cubic centimeter (g/cm³). This unit is particularly relevant in bone densitometry because it directly reflects the density of bone mineral content within a given volume of bone. By using this volumetric approach, QCT effectively measures the bone density at specific sites, providing critical information for assessing bone health and fracture risk.

This measurement method is advantageous in distinguishing between cortical and trabecular bone and can present a more accurate depiction of bone quality compared to other techniques. In contrast, other units mentioned do not apply in this context; for instance, milligrams per deciliter (mg/dL) is commonly used for blood chemistry, while milligrams per square centimeter (mg/cm²) relates more to surface area measurements, and grams per milliliter (g/mL) is often utilized in fluid density contexts, not specifically for bone density assessment in QCT.