Reporting Radiographs

Question 1

X ray photons interact with the tissues and can be:

Answer 1

– Absorbed (not reaching image receptor)

• Scattered (reach image receptor but information not helpful)

–Pass through and reach image receptor giving useful information

Question 2

Why are radiographic images made of varying shades of grey?

Answer 2

due to the different absorption of x-rays by the tissues

Question 3

What structures appear white?

Answer 3

Dense structures absorb more x-rays

• E.g. enamel, cortical bone, metal

Question 4

What structures appear dark grey?

Answer 4

Soft tissues

Question 5

What structures appear black?

Answer 5

Air absorbs no photons so appears black

Question 6

How should we view a radiograph film ?

Answer 6

– Darkened room
– A light box providing a homogeneous light source, with an optional focal spot of bright light
– Magnifier.

Question 7

How should we view a digital radiograph

Answer 7

– Darkened room
– Minimal direct and reflected light
– Diagnostic monitor with tested standards of resolution and contrast display
– Monitor positioned at eye level

Question 8

What is SMPTE

Answer 8

A test pattern for monitors to ensure adequate image display for diagnosis

Question 9

in SMPTE what do high and low contracts line pair to

Answer 9

Test resolution

Question 10

Which contrast squares are central?

Answer 10

5% and 95%

Question 11

What is a radiographic report?

Answer 11

description of any disease detected and a recording in the notes that the image has been clinically evaluated

Question 12

Which radiographic images should have a radiograph report?

Answer 12

All of them- legal requirement

Question 13

According to the IR(ME)R19, Who’s role is it to report a radiograph?

Answer 13

Operator role

Question 14

According to the IR(ME)R19, what must the legal person provide?

Answer 14

procedures to ensure that a clinical evaluation of the outcome of each exposure is carried out and recorded.

Question 15

When will the expose be unjustified and must not take place

Answer 15

If it is known prior to the exposure taking place that no clinical evaluation will occur

Question 16

What should the contents of a radiographic report be?

Answer 16

• The report should demonstrate that each radiograph has been evaluated
• Record pathological findings and/or key negative findings
• A description of pathological findings to allow someone to visualise the image, even if they cannot see it
• Should include sufficient information so that it can be subject to later audit

Question 17

When interpreting the images, you will be looking at one of these:

Answer 17

– of patients who are symptom free but you are checking for occult disease, for example caries on bitewings
– of patients with specific symptoms which direct you to a certain technique and pathology

Question 18

What may help you see an incidental finding?

Answer 18

Look at the image methodically

Question 19

What is the procedure for reporting a radiograph?

Answer 19

• View under optimum conditions
• Identify it is the correct patient
• Ensure the film is dated
• Correctright/leftorientation
• Identify film faults which may render diagnosis impossible
• Examine full radiograph with a systematic approach.
• Describe radiographic features of pathology
• Form a differential diagnosis
• Compare with previous imaging
– Assess for stability, progression or resolution.

Question 20

What is the systematic approach for viewing radiographs

Answer 20

• Identify any artefacts which might be mistaken for pathology
• Identify normal anatomical features and variants of normal
• Teeth, apical tissues and periodontal tissues – URQ → ULQ → LLQ → LRQ
• Assess other structures
– Body/ramus of mandible on OPT – Antral floor
– Nasal cavity

Question 21

Describe radiolucency

Answer 21

– Black on image
– Caused by area of decreased density
– More x-rays passing through to interact with receptor, e.g. air, less bone

Question 22

Describe radiopacity/ radiodensity

Answer 22

– Whiter on image
– Fewer x-rays reaching receptor as resorbed by denser tissue e.g. bone

Question 23

What dental diseases causes relative radiolucency?

Answer 23

Caries: loss of mineral in enamel and dentine

Periodontal disease: loss of bone at the alveolar crest

Question 24

Some pathologies/anomalies can result in an increase in tissue volume or density, making it appear more..

Answer 24

Radiopaque

E.g supernumerary tooth

Question 25

What is a lesion?

Answer 25

A lesion is a region in an organ or tissue which has suffered damage through injury or disease, such as a wound, ulcer, abscess, or tumour.

Question 26

What do lesions look like in radiographic images?

Answer 26

Lesions have different characteristics, producing different radiographic appearances.

Question 27

What do we look at when reporting a lesion?

Answer 27

• Location
• Size
• Density
– Radiolucent/ radiopaque/mixed density
• Shape
• Margins
• Effects on surrounding structures

Question 28

What can we say about the location of a lesion?

Answer 28

• Maxilla/mandible/soft tissues
• Relation to teeth
– Which teeth
– Which part of tooth • Apex
• Root
• Crown
• Position above or below the ID canal

Question 29

What can we say about the size of a lesion?

Answer 29

• Direct measurement
– Remember to give units e.g. cm, mm
– Some radiographs have inherent magnification (e.g. 1.2-1.7 x magnification in panoramics) so measurements may not be precise
• In the jaws we can describe size relative to adjacent structures.

Question 30

What can we say about the density of a lesion?

Answer 30

• Homogeneous (uniform, smooth) – Radiolucent (dark)
– Radiopaque (light)
• Heterogeneous
– Mixed density
– Mix of radiolucent and radiopaque areas

Question 31

What can we say about the shape of a lesion?

Answer 31

• Circular
• Lobulated
• Sausageshaped
• Expansile

• Unilocular
• Multilocular
• Pseudolocular

Question 32

What can we say about the margins of a lesion?

Answer 32

• Smooth
• Lobular
• Irregular/ regular, smooth
• Corticated
• Partially corticated
• Well-defined
• Ill-defined/diffuse

Question 33

Effect of lesions on bone cortices

Answer 33

– May be eroded
– Lesion may be expansile, ‘pushing’ and thinning the bony cortices as the bone is expanded.

Question 34

Effect of lesions on teeth?

Answer 34

– Displaced
– Resorbed
• Inferiordentalcanal • Maxillaryantrum

Question 35

Limitations of radiographs

Answer 35

• Remember a radiograph is a 2D representation of 3D structure
• Always consider need for another view at a different angle (Parallax technique/SLOB rule)
• This is especially important to – Localise a radiodensity
– Assess a fracture

Question 36

What do the cortical margins of benign and slower growing lesions tend to look like?

Answer 36

Well defined cortical margins

Question 37

What do the cortical margins of malignant, more rapidly growing lesions tend to look like?

Answer 37

More irregular, poorly defined margins
- related to speed of bone destruction

Question 38

What do margins on infected lesions look like?

Answer 38

Ill-defined margins and can appear more sinister

Question 39

What is a differential diagnosis?

Answer 39

is a list of possible conditions fitting the clinical scenario

Question 40

What is a clinical differential diagnosis based on

Answer 40

clinical signs and symptoms

Question 41

What is a radiological differential diagnosis based on

Answer 41

key features observed in imaging

radiological differential diagnosis can support or inform the clinical differential diagnosis.

Question 42

Interpreting radiographs requires application of knowledge of what 4 things

Answer 42

– Optimal viewing conditions for looking at imaging
– Normal anatomy
– Radiographic artefacts
– Features of pathological lesions