Introduction to radiology and imaging

Question 1

What is radiology

Answer 1

Medical discipline that uses imaging to diagnose and treat disease

Question 2

Different types of imaging that radiologists use

Answer 2

• xray
• Ultrasound
• Computed tomography
• MRI
• Nuclear medicine

Question 3

What are the types of imaging that use ionising radiation

Answer 3

• Plain xray
• Computerised tomography
• Fluoroscopy
• Nuclear medicine

Question 4

What type of imaging uses high frequency sound waves

Answer 4

Ultrasound

Question 5

What type of imagine uses high strength magnet field and radio frequency waves

Answer 5

MRI

Question 6

What structures are well visualised by ultrasound

Answer 6

Soft tissue, fat and fluid filled structures

Question 7

Benefits of CT scans

Answer 7

• quick scanning of large areas of the body
• Provides good anatomical information in multiple planes
• Appropriate to assess for most acute clinical problems

Question 8

Drawbacks of CT scans

Answer 8

• Can involve large doses of ionising radiation
• Risk of allergy to iodine based contrast
• Poor at assessing the spinal cord and reproductive organs

Question 9

Benefits of fluoroscopy

Answer 9

• Real time anatomical assessment
• COmmonly used for interventional procedures
• Low radiation dose

Question 10

Drawbacks of fluoroscopy

Answer 10

• Always require use of contrast agents

- Poor soft tissue assessment and overlapping anatomy

Question 11

Benefits of MRI

Answer 11

• Doesnt use ionising radiation
• Excellent anatomical detail
• MUltiple phases enable some functional assessment of tissues

Question 12

Drawbacks of MRI

Answer 12

Time consuming and expensive

• Safety issues regarding metallic implants
• Claustraphobic

Question 13

Benefits of ultrasound

Answer 13

• Real time assessment
• Doesn’t involve ionising radiation
• Used for paediatric and antenatal imaging

Question 14

Drawbacks for ultrasound

Answer 14

• Poor assessment of air filled structures and bone
• More heavily operator/patient dependent
• Attenuation of sound waves limits scan depth

Question 15

Benefits of Nuclear Medicine

Answer 15

• large number of tracers available to assess different tissues
• Provides anatomical and functional information
• Allows more definitive assessment of pathology identified on other modalities

Question 16

Drawbacks of Nuclear Medicine

Answer 16

• Scan acquisition is time consuming
• Poor resolution compared to alternative cross-sectional imaging
• Radiation exposure continues after termination of examination

Question 17

Different between deterministic and stochastic effects

Answer 17

Deterministic- There is a threshold dose for symptoms of radiation

Stochastic- Assumes there is no threshold dose as the effects are not clear because of other cancer promoting factors such as drinking and smoking

Question 18

Three laws to do with radiation

Answer 18

Ionising Radiation Regulations (IRR) = protection of employees against exposure

Ionising Radiation Medical Exposure Regulations (IRMER)
=Protects patients

ALARP Principle = acceptable region, tolerable region and unacceptable region