Quantitative computed tomography (QCT) is a bone mineral density (BMD) measurement technique in which the CT scanner is calibrated using solid phantoms (made of calcium hydroxyapatite, representing various bone mineral densities) placed under the patient in a pad. With this calibration, the Hounsfield units are converted to bone mineral density values.
The technique can be used for both peripheral and central BMD measurements, with lumbar spine and hip being preferred locations.
- more radiation dose compared to dual-energy X-ray absorptiometry (DEXA)
- can be used in cases of scoliosis
- can be helpful in obese
- spinal degenerative process does not significantly affect the results (c.f. DEXA)
- can be used for both trabecular and cortical bone