Radiology Flashcards
1
Q
Describe colours in X ray
A
- Bone has high attenuation so appears white
- Lungs appear black due to low attenuation
- Soft tissues appear grey
2
Q
Describe colours in CT scan
A
- Bone has high attenuation so appears white
- Lungs black due to low attenuation
- Soft tissues appear in shades of grey
3
Q
What is ground glass opacification?
A
- Air is not completely displaced
- Pattern telling you there is something displacing air in the airways or interstitium
- Could be haemorrhage, hypersensitivity pneumonitis
4
Q
Compare consolidation and ground glass opacification
A
- When I see consolidation I say to myself that there is some pathology in the lungs which has COMPLETELY displaced (e.g. by infection, blood, tumour).
- When I see ground glass what I tell myself is that the air has been PARTIALLY displaced.
- It may be the same pathological processes
5
Q
Describe appearance of consolidation
A
- Different density to the lungs (white)
- Ill defined, fluffy.
- Confluent
- Loss of vessel pattern
- Air bronchograms (dark bronchial outline that can be seen within the consolidation. Alveoli filled with material and bronchioles still gilling with air)
6
Q
Describe appearance of nodule or mass
A
- Nodule less than 3mm
- Mass more than 3mm
- Round opaque lesions on X ray
7
Q
Describe appearance of pneumothorax
A
- Visible visceral pleural edge is seen as a very thin, sharp white line
- No lung markings are seen peripheral to this line
peripheral space is radiolucent compared to the adjacent lung - Lung may completely collapse
- Mediastinum should not shift away from the pneumothorax unless a tension pneumothorax is present
- Subcutaneous emphysema and pneumomediastinum may also be present
8
Q
Describe appearance of pleural effusion
A
- Very dense
- Meniscus (fluid line - as you get towards the wall of the lungs the level of the opacity increases)
- Density highest at the base and gradually less dense as you move up
- Obliteration of the hemidiaphragm and costo-phrenic angle
- Pulls trachea towards opposite side
9
Q
Describe appearance of atelectasis
A
- Shifted mediastinum towards the collapsed side
- White out due to lack of air
- Lung volume loss
10
Q
Describe the difference between haustra and valvulae conniventes
A
- Haustra are not complete, only partway through the lumen. Enlarged haustra suggest large bowel obstruction
- Valvulae conniventes are circular folds going the whole way through the bowel wall, suggest small bowel obstruction
11
Q
Describe a cavitating lesion
A
- A lucent area contained within a consolidation, mass, or nodule
- Air fluid level
12
Q
List causes of cavitating lung lesions
A
- Infection (TB, staph, klebsiella eg. alcoholics)
- Inflammation (RA)
- Infarction (PE)
- Malignancy
13
Q
Compare CXR appearance of pulmonary fibrosis and pulmonary oedema
A
- Honey combing pulmonary fibrosis (course)
- Ground glass is pulmonary oedema (fine)
14
Q
Describe AXR analysis
A
- Air
- Bowel
- Dense structures (bone, calcification)
- Organs and soft tissues
- X- eXternal organs and artifacts (eg. JJ tube goes from skin to kidney to bladder, nephrostomy tube connects this to the skin)
15
Q
Define pneumoperitoneum
A
Air under the diaphragm, due to bowel perforation
