DXA measures areal BMD and reports it in which unit?

• A. mg/cm^3
• B. kg/m^2
• C. g/cm^2
• D. mg/mL

Answer: (C)

DXA provides an areal measurement of bone mineral density, which means mineral content is divided by the projected bone area. The mineral content is in grams and the area in square centimeters, so the resulting unit is grams per square centimeter (g/cm^2). This reflects the two-dimensional nature of DXA data. Volumetric density units like mg/cm^3 or mg/mL would require three-dimensional measurement not provided by DXA, and kg/m^2 isn’t the standard reporting for DXA BMD. Hence, g/cm^2 is the appropriate unit.