Radiology

Question 1

What is a CT scan?

Answer 1

A digital image, formed by transmitting x-rays at various angles through the body.
A 3D image is created, by stacking images.

Question 2

What is attenuation?

Answer 2

Different densities of tissue absorb or transmit x-rays differently.

Question 3

What are some important details about CT?

Answer 3

Cheap.
3D.
Uses ionising radiation.
Poor soft tissue detail.
Excellent bone detail.

Question 4

What are MRIs used for?

Answer 4

Highlighting pathology in nervous tissue.
Key in determining CNS problems.

Question 5

What are some important details about MRI?

Answer 5

Expensive.
3D.
No ionising radiation - safe in pregnancy.
Excellent soft tissue detail.
Poor bone detail.

Question 6

How is an X-Ray interpreted?

Answer 6

High density (bone) - white.
Intermediate density (muscles, fat) - grey.
Low density (lungs) - black.

Question 7

What are some important details of X-Rays?

Answer 7

Cheap.
2D.
Uses ionising radiation.
Poor soft tissue detail.
Excellent bone detail.

Question 8

What is US used for?

Answer 8

Point of care scanning for diagnosis and performing procedures.

Question 9

What are the different types of structures seen by US?

Answer 9

Hyperechoic - bright (bones, fat, stones).
Hypoechoic - dark (cartilage, muscle).
Anechoic - black (fluid).

Question 10

What are some important details of US?

Answer 10

Cheap.
2D.
No ionising radiation.
Poor soft tissue and bone detail.