**3.3 Radiological markers**

Dual-energy X-ray absorptiometry (DEXA) is the conventional method used for BMD assessments. DEXA employs the use of low ionizing radiation and measures the calcium content in bone in terms of grams of hydroxyapatite/cm2 .

Quantitative ultrasound is another technique that is relatively inexpensive and measures the mineral content of bone as well as the organic matrix. The parameters that are evaluated by the abovementioned technique are the speed of sound and bone transmission time [15].
