Question

After performing a CT of the chest, an ROI placed in the air outside of the patient yields of an average CT number of -1,223. This error represents a problem with:

Answer 1

The error in the average CT number of -1,223 obtained when placing an ROI in the air outside of the patient after performing a CT of the chest indicates the problem of poor quality images.

Step-by-step explanation:

The error in the average CT number of -1,223 obtained when placing an ROI in the air outside of the patient after performing a CT of the chest indicates the problem of poor quality images. CT scans are used to create detailed cross-sectional images of the body, but when an ROI is placed in an area devoid of anatomical structures like air, it is expected to have a CT number close to zero. The significantly negative CT number suggests the presence of image artifacts or calibration errors, leading to the poor quality of the CT images.