Computed Tomography Test CT Radiation Safety and Dosimetry 2

Question 1

The DLP (Dose Length Product) in CT is calculated by multiplying CTDI_vol by which parameter?

Accepted Answer

Scan length

Answer

DLP = CTDIvol × scan length (in cm), providing an estimate of total energy deposited during the entire CT examination.

Question 2

Which of the following best describes the dose profile of a helical CT scan with a pitch greater than 1?

Accepted Answer

Gaps exist between dose profiles from successive rotations

Answer

A pitch >1 means the table moves faster than one detector width per rotation, creating gaps in the dose profile and generally reducing patient dose.

Question 3

In CT, which body region is most sensitive to radiation-induced cancer risk?

Accepted Answer

Bone marrow and gonads

Answer

Bone marrow and gonads have the highest tissue weighting factors (wT), making them most sensitive to stochastic radiation-induced cancer risk.

Question 4

What is the recommended lead apron shielding thickness to protect gonads from scattered CT radiation?

Accepted Answer

0.5 mm lead equivalent

Answer

A 0.5 mm lead equivalent apron is standard for gonadal shielding, though its effectiveness in CT is debated due to scatter from all directions.

Question 5

Which population group requires the most careful dose optimization in CT due to higher radiation sensitivity?

Accepted Answer

Pediatric patients

Answer

Children are more radiosensitive than adults and have more years of life remaining in which radiation-induced cancers could develop, requiring strict dose minimization.

Computed Tomography Test Practice Test

Computed Tomography Test Practice Test

Computed Tomography Test CT Radiation Safety and Dosimetry 2