Image Formation

Question 1

What is list mode?

Answer 1

Series of x and y locations of data that cannot be viewed directly –> must be reconstructed

Question 2

How does list mode data create a sinogram?

Answer 2

A 2D array is created using angle and offset characteristics of detected events. This is used to reconstruct the image

Each row: projection at specific angle

Question 3

What is the process for image formation in SPECT?

Answer 3

1. Collimator defines projection lines
2. Acquire different projection angles
3. Apply FBP algorithm
4. Filter kernal
5. Attenuation correction

Question 4

Filtered Back Projection (FBP) Algorithm

Answer 4

1. Acquire projections at different angles
2. Apply filter kernal
   –> FT
   –> filter function
   –> inverse FT
3. backprojection
4. Repeat :)