Exam 9: Image Quality

CT number uniformity can be affected by all of the following factors except:

Partial volume averaging occurs when linear attenuation coefficients for a voxel of tissue contains only one tissue type resulting in streaking artifacts within the CT image.

Cross-plane spatial resolution is traditionally described by the:

Partial volume artifacts can be reduced with _____________ slice acquisitions and computer algorithms.

Artifacts can have all of the following effects except:

In CT, artifacts can arise from a number of sources, including the patient, inappropriate selection of protocols, reconstruction process, and problems relating to the equipment.

Because the CT acquisition and reconstruction process is band limited, the reconstructed image of a bar pattern is a blurred version of the original object.

All of the following are operator-controlled factors that affect image noise except:

How do beam-hardening artifacts appear on a CT image?

What term is in-plane resolution measured?

Metallic materials usually present as ____________ artifacts on the image.

Scatter-induced artifacts can be corrected with algorithms by carefully measuring or estimating the scatter distribution in the projection.

What types of artifacts can arise from insufficient projection sampling or from insufficient view sampling?

Which of the following describes the scanner's ability to resolve closely placed objects that are significantly different in the background?

Linearity can be checked by a yearly calibration test.

What refers to an increase in the mean energy of the X-ray beam as it passes through the patient?

All of the following can be described as image quality parameters except:

Which of the following refers to the relationship of CT numbers to the linear attenuation coefficients of the object to be imaged?

If the field of view is 30 cm with a matrix size of 512 * 512, what is the pixel size?

Coverage is a method of reducing cardiac motion in CT imaging by synchronizing data acquisition and reconstruction with an electrocardiographic signal.