ACR QC Program
The Daily ACR QC should be performed prior to the first clinical scan of the day. After the images are acquired, the technologist should verify that the images are free of artifacts and perform simple measurements to ensure that the system performance is within the action limits prior to the first clinical scan of the day.
The QC scan protocol consists of an Axial protocol (Routine Brain), a Helical protocol (Routine Abdomen) and one or more Axial scans designed to increase the sensitivity of artifact analysis. All images generated by the QC must be visually inspected for artifacts.
The QC protocol should be used to scan the manufacturers water phantom. A quantitative measurement is performed is performed by placing a 400mm2 Region of interest (ROI) in the center of the image. The mean water value and standard deviation are recorded on the included forms.
You do not need to measure both the Axial and Helical datasets each day. The quantitative analysis may be performed by alternating the measurement of the Axial and Helical datasets.
The mean CT number for water must be within -5 HU to 5 HU. The standard deviation must be within 20% of the established baseline values. The worksheet below will aid in the computation of the allowable ranges for water standard deviation.