Imaging

Question 1

What are some imaging methods?

Answer 1

Light – photography

X-rays: – Radiographs

– Computed tomography

• CT scans
• CBCT (Cone beam CT) scans

Magnetic resonance

Ultrasound

Nuclear isotopes

Question 2

Why do we need imaging?

Answer 2

Visualise tissues and pathologies that are not directly visible Help make a diagnosis Aid in treatment planning Help guide treatment Monitor outcomes

Question 3

Who invented x-rays and when were they invented?

Answer 3

Wilhelm Roentgen 8th November 1895

Question 4

What are x-rays?

Answer 4

Electromagnetic radiation Photons – packets of energy Beam = millions of photons

Question 5

How are X-rays produced?

Answer 5

Question 6

What are the different types of x-ray detections?

Answer 6

Radiographic film

– Film packet

– +/- Intensifiers

Digital receptors

– Solid state sensors (like in a camera)

– Phosphor plates

Question 7

What is in a dental film packet?

Answer 7

Film packet

Lead foil

Film

Black Paper

Question 8

What is the radiation does for Panoramic and Periapical radiographs?

Answer 8

Panoramic 4-30 µSv

Periapical 1-8.3 µSv

Question 9

When using an X-ray what must you do to mimise the does?

Answer 9

Must justify the need/benefit

Technique: – Fast film / sensor

– Film holders

– Collimators

– Intensifying screens

Question 10

What are some intraoral radiograph views?

Answer 10

Bitewing

Periapicle

Question 11

What are X-ray properties?

Answer 11

X-ray properties

 Undetectable by human senses

 Short wavelength: – higher energy, greater penetration

 Longer wavelength: – lower energy, less penetration – “soft x-rays”

 X-ray energy can be attenuated by matter – Absorbed and scattered

 Can produce IONISATION and tissue damage

 Can affect a film or digital sensor to produce an image

Question 12

X-ray innteractions with matter

Answer 12

If beam passes through air - black

 If beam passes through bone - greyish

 If beam passes through metal - white