Notes from CT for Technologists - ROMANS

Question 1

What is the range of HU numbers?

Answer 1

-1000 (air) to +1000 (dense bone)

Question 2

What is another name for ‘raw data’?

Answer 2

scan data

Question 3

What is the general range of kVp for CTs?

Answer 3

120 - 140 KV

Question 4

What term describes the quantity of Hounsfield units represented as shades of gray on a specific image?

Answer 4

Window Width

Question 5

What term describes the center CT value of the window width?

Answer 5

Window Level

Question 6

What color will values higher than the selected window width be displayed as?

Answer 6

white

Question 7

What color will values lower than the selected window width be displayed as?

Answer 7

black