AM in Medicine

Question 1

What are the 4 different stages of making a medical scan usable?

Answer 1

1. Thresholding
2. Segmentation
3. Manual operations
4. Output

Question 2

What is thresholding?

Answer 2

removes unwanted areas of the image, separating hard and soft tissue in the process.
Works by defining a range of greyscale values, only the parts of the image within this range are included. the greyscale is representative of the density of material

Question 3

What is segmentation?

Answer 3

Removes outlying points from threshold areas. A single, completely connected region remains
Points are selected manually or by defining a number of connected pixels in a single layer. Lesser numbers of connecting pixels are removed from the mask, this is ready to be converted to a 3 dimensional model.

Question 4

What are the manual operations needed for cleaning up a medical scan?

Answer 4

Erode- smooths outer surface by removing pixels
Dilate - smooths outer surface by adding pixels
Open - holes and spaces are expanded
Close - Holes and spaces are removed

Provides the user with more control over the geometry of the 3D model to be produced

Question 5

What is the output after cleaning up a medical scan?

Answer 5

Final model
Selected regions of the layer stack can then be combined to form a 3D model to be viewed on screen or exported in various formats such as STL, IGES, point cloud