Which calibration method uses a QC block in its process?

• A. Internal Calibration
• B. Standard Calibration
• C. External Calibration
• D. Factory Calibration

Answer: (C)

The calibration method that employs a QC (Quality Control) block is external calibration. This approach involves the use of a standardized reference or a QC block, which is an external object that has a known density. During the calibration process, the densitometer measures the attenuation of X-rays as they pass through the QC block, allowing the machine to adjust its readings based on these known values.

In external calibration, the QC block serves as a benchmark to ensure that the system produces accurate measurements over time, and it is essential for maintaining the reliability of bone density assessments. This method provides vital checks against any drifts in the system's accuracy due to changes in environmental conditions or equipment wear.

While other calibration methods may incorporate different procedures or checks, external calibration specifically highlights the use of a QC block to facilitate ongoing quality assurance and verification of measurement precision. This helps uphold the integrity of bone density evaluations, which can influence patient care decisions.