Medical Imaging

Question 1

Radiology

Answer 1

Branch of medicine using radioactive material in diagnosis & treatment

Question 2

Radiologist

Answer 2

Doctor specially trained to interpret diagnostic images

Question 3

Radiographer

Answer 3

Healthcare professional trained to take e.g. X-rays

Question 4

X-rays

• how produced
• lighter grey due to…

Answer 4

• Beam of X-rays passes through body, X-rays = absorbed or scattered (= attenuation of beam)
• Higher density/mr = more attenuation

Question 5

Colour of air/gas on an X-ray…

Answer 5

Black

Question 6

Colour of soft tissues/ water on an X-ray…

Answer 6

Light grey

Question 7

A-P X-ray

Answer 7

Taken anterior to posterior

Question 8

A-P or P-A X-ray better for heart? Why?

Answer 8

P-A

As heart is against the detector, so less magnification

Question 9

Mammography

• what
• purpose
• advantage

Answer 9

• Soft-tissue X-ray
• Breast cancer
• Lower dose of X-rays used

Question 10

Fluoroscopy

• what
• purpose
• example
• appearance

Answer 10

• Continuous X-ray on a monitor
• Real-time examination
• e.g. movement of body part, contrast agent
• -ve X-ray

Question 11

Angiography

• how produced
• purpose

Answer 11

• Contrast agent injected into blood, makes it visible on X-ray
• Examination of arteries/veins/organs

Question 12

What does CT stand for

Answer 12

Computed Tomography

Question 13

CT

• how produced
• radiation dose

Answer 13

• X-rays produce 2D slice of a single tissue (cross-sectional imaging)
• High

Question 14

Scintigraphy

• what
• process x5
• shows

Answer 14

• nuclear medicine
• injection of radoopharmaceuticals, emits gamma rays, detected by gamma camera, converts energy to electric signal, then image
• functional info (e.g. ‘hot spots’ in blood supply)

Question 15

What does SPECT stand for?

Answer 15

Single Photon Emission CT

Question 16

SPECT

• kind of technique
• advantage

Answer 16

• Scintigraphic technique

- Greater detection of lesions overlain by other structures

Question 17

SPECT-CT

• what
• advantage

Answer 17

• Sensitive SPECT finding fused w anatomical CT images

- Further enhances SPECT accuracy

Question 18

What does PET stand for?

Answer 18

Positron Emission Spectrum

Question 19

PET

• what
• how produced
• when commonly used

Answer 19

• Combo of CT & scintillation scanning
• Radionuclides injected & decay by positron emission
• Oncology

Question 20

What does MRI stand for

Answer 20

Magnetic Resonance Imaging

Question 21

MRI produces…

Answer 21

Detailed images of internal structures as cross sections

Question 22

How MRI works x5

Answer 22

• Each proton spins on a diff axis
• External magnet –> likes up axes in direction of field
• Small pulse of radio waves –> tips axes
• Radiowaves removed –> axes re-align
• Releases energy (determined by proton location & number) –> detected by receiver

Question 23

T1 MRI images

Answer 23

Highlight fat

Question 24

T2 MRI images

Answer 24

Highlight fat & water

Question 25

X-ray Advantages x3

Answer 25

- Images in diff. planes - Quick - Live-action images

Question 26

X-ray Disadvantages x2

Answer 26

- High radiation | - Have to position (PA vs AP)

Question 27

CT Advantages x3

Answer 27

- Fast (e.g. if agitated) - Readily available - Good imaging of bony structures, lungs, abdomen

Question 28

CT Disadvantages x2

Answer 28

- High radiation | - Not to good at imaging soft tissue

Question 29

Scintigraphy Advantages x2

Answer 29

- Good functional info | - Good localisation of pathology

Question 30

Scintigraphy Disadvantages x2

Answer 30

- High radiation | - Not good at differentiating between pathologies (says something is wrong, not what is)

Question 31

MRI Advantages x4

Answer 31

- No radiation - Good localisation of pathology - Good image quality - Excellent soft tissue imaging

Question 32

MRI Disadvantages x4

Answer 32

- Dangerously strong magnet - Not so good at bony anatomy - Expensive - Long scanning duration

Question 33

Ultrasound Advantages x3

Answer 33

- No radiation - Portable - Live-action

Question 34

Ultrasound Disadvantages x3

Answer 34

- Operator dependent - Structures surrounded by bone aren't clearly seen - Structures in abdominal organs = obscured by gas in over lying bowel