Medical Imaging

Question 1

What are the 4 types of radiation in X-Rays?

Answer 1

• Primary
• Scatter
• Absorbed
• Remnant

Question 2

What is attenuation regarding to X-Rays?

Answer 2

The degree to which density relates to absorption of radiation

Question 3

Name 3 conditions that can be identified using an X-Ray

Answer 3

• Bone fractures
• Lung consolidation/infection
• Volvulus
• Vascular narrowing

Question 4

What are the negatives of using X-Rays?

Answer 4

• Ionising radiation
• 2D imaging
• Poor for soft tissue

Question 5

Describe the 5 positioning terms in radiology

Answer 5

Superior - Top
Inferior - Bottom
Anterior - Front
Posterior - Back
Medial - Towards the midline
Lateral - Away from the midline

Question 6

What are the 3 planes of imaging?

Answer 6

• Coronal
• Transverse/Axial
• Sagitta

Question 7

Name 2 organs that lie to the left and two that lie to the right hand side

Answer 7

Left - Spleen/stomach/heart

Right - Appendix/liver

Question 8

What are the units of attenuation?

Answer 8

Hounsfield Unit

Question 9

How is a CT scan achieved?

Answer 9

Uses x-rays to create a 3D image by continuous rotation of X-ray tube and detectors

Question 10

What are the issues of CT scans?

Answer 10

• High ionising radiation

- Poor soft tissue detail

Question 11

What view does a Ct scan show?

Answer 11

Uses transverse sections to produce an axial view looking from feet end up

Question 12

Name 3 common images and conditions identified by CT scans

Answer 12

Head - tumour/bleed
Chest - PE
Abdomen - bowel obstruction
Pelvis - bladder stone

Question 13

What is Fluoroscopy?

Answer 13

Serial x-rays taken in a sequence with contrast showing dynamic flow through a system

Question 14

What does PET stand for?

Answer 14

Position Emission Tomography

Question 15

What is PET combined with and what does it show?

Answer 15

Combined with CT scanning to give a 3D view of metabolically active tissue using radioactively labelled glucose

Question 16

How does an MRI produce an image?

Answer 16

• Measures spin of hydrogen atoms using strong magnet

- Unmatched atoms emit energy which sends a signal to the computer producing an image

Question 17

Name 3 uses of an MRI scan

Answer 17

Head - CVA
Spine - slipped disc
Liver - gallstones
Knee - torn ligament

Question 18

Name 2 advantages and disadvantages of MRI

Answer 18

Advantages - High detail and no radiation

Disadvantages - Expensive, Noisy, Can’t be used with metal implants

Question 19

What effect is used in ultrasound and how does it work?

Answer 19

• Piezoelectric Crystal Effect

- Pressure on crystals by reflection generates current for the computer

Question 20

What is the difference between high and low frequency?

Answer 20

High - short wavelength/penetration with good resolution

Low - long wavelength/penetration with poor resolution

Question 21

Name two advantages and disadvantages of ultrasound

Answer 21

Advantages - dynamic, quick

Disadvantages - poor detail, can’t see past air