What type of scan is used for gain adjustment in PET quality control?

The Blank Scan is used for gain adjustment in PET quality control because it provides a baseline measurement of the detector response without the influence of any radioactive source. During a Blank Scan, the system captures the inherent noise and the baseline signal from the detectors when no radioactive materials are present. This allows for the assessment of the system's stability and performance, helping to identify any deviations or artifacts in the image caused by electronic or environmental factors.

In the context of quality control, establishing a reference value using the Blank Scan enables practitioners to adjust the gain settings appropriately, ensuring optimal image quality and accurate measurement of radiotracer distribution during the functional imaging of patients. This is crucial for eliminating potential errors and ensuring consistent performance across imaging sessions.

The other scan types, while relevant for different aspects of quality control or imaging, do not serve the specific purpose of gain adjustment in the same way. For example, a Uniform Cylinder Scan is typically utilized to assess spatial resolution and uniformity, while a Point Source Scan focuses on evaluating detector sensitivity and spatial resolution. A Diagnostic Imaging Scan is primarily aimed at the clinical evaluation of structures and is not designed for the specific calibration and gain adjustment tasks.