DIGITAL IMAGE PROCESSING

Question 1

Define the term ‘pixel bit depth.’ (2 marks)

Answer 1

• The number of bits that have been made available in the digital system to represent each pixel in the image.
• Example: with 4 bits, a pixel would be limited to having 16 different values (brightness levels or shades of grey); 8 bits = 256 different values.

Question 2

List 3 examples of image reconstruction techniques used in CT. (3 marks)

Question 3

What is digital subtraction angiography (DSA)? (2 marks)

Question 4

Why is DSA used? (2 marks)

Question 5

Explain the concept of a Look Up Table (LUT) and give an example to show how it works to enhance image contrast. (7 marks)