Quantitative computed tomography

Quantitative computed tomography (QCT) is a medical technique that measures bone mineral density (BMD) using a standard X-ray computed tomography (CT) scanner with a calibration standard to convert Hounsfield units (HU) of the CT image to bone mineral density values.

Douglas Boyd, PhD and Harry Genant, MD used a CT head scanner to do some of the seminal work on QCT.

Today, modern 3D QCT uses the ability of CT scanners to rapidly acquire multiple slices to construct three-dimensional images of the human body.

Using other non-IV contrast abdominal or pelvic scans such as a Virtual Colonography studies, the QCT exam can be performed without requiring any further image acquisition or consequent radiation dose to the patient.

Using pre-existing images, including CT colonography exams,[14] QCT allows for bone density screening without submitting the patient to any additional radiation exposure.

In medicine, peripheral quantitative computed tomography, commonly abbreviated pQCT, is a type of quantitative computed tomography (QCT), used for making measurements of the bone mineral density (BMD) in a peripheral part of the body, such as the forearms or legs as opposed to QCT that measures bone mineral density at the hip and spine.

High-resolution peripheral quantitative computed tomography (HR-pQCT) is better than DXA at detecting bone microarchitecture, modeling whole-bone geometry using 3-dimensional information from scans.