Radiology Flashcards
What is the best type of CXR? Why?
PA
- Scapula’s out of the way
- Heart near detector so can interpret
What is the advantage to an AP CXR?
Can be done lying, so more unwell pt
How can you tell a tension pneumothorax from a N pneumothorax on CXR?
In a tension pneumothorax there is:
- Increased chest expansion
- Heart may be compressed
- Diaphragm may be depressed
When assessing image quality/adequacy on a chest x-ray what 4 things do you need to assess?
RIPE
Rotation
- check the ends of the claviculae are equidistant from the spine.
Inspiration
- 6 anterior ribs (the ones that are hard to see)
- Lung apices
- Both costophrenic angles
Projection
- Is it an AP or PA (PA better)
Exposure
- Left hemidiaphragm visible to the spine and vertebrae visible behind the heart
How do you say something is more white on a XR?
Increased density/opacity
How do you say something is darker on an XR?
Increased lucency
When going through the CXR how do you structure it? (Details of approach)
Pt details
Adequacy (RIPE)
Any striking abnormalities
ABCDE
Airway
- Trachea deviated?
- Is the mediastinum enlarged (lymphoma or thyroid)
- Carina visible?
- Hilum okay, lymph nodes?
Breathing
- Lung markings & pleura (if reduced pneumothorax)
- Look from apex to base (divided into 3rds on L and R)
- Liquid? Pleura/alveoli (Pulmonary oedema)
Cardiac
- Cardiothoracic ratio (<50% of thorax)
- Look for cardiac borders (if fuzzy then consolidation)
Diaphragm
- Costophrenic angle visible?
- Any air under the R hemidiaphragm?
Everything else
- Bone
- Soft tissue
- Look for any tubes or lines
What would cause a lung collapse on CXR?
- Tumour (adult)
- Foreign body (child)
- Mucus plugging in infection
What GFR do you need to have a Contrast scan?
> 40 (if not on dialysis - which would be okay)
What are the three phases of a contrast CT scan?
Pre-contrast
Arterial
Portal-venous
What colour is the grey matter on a CT?
White
What colour is the white matter on a CT?
Darker grey
is low attenuation black or white?
Low attenuation = black
Is high attenuation black or white?
High attenuation = white
If there is high attenuation areas in the sulci what is this?
SAH
In a bleed if the blood is dark then is it old or young?
Dark = old
In a a bleed if the blood is white is it old or young?
White = young
What vessels are bleeding in a subdural haemorrhage?
Bridging veins crossing the subdural space
If there is old and acute blood both in a CT head, what is likely going on?
An old subdural that is rebleeding.
What does a central high attenuation star show?
Extensive SAH
Two main causes of SAH?
- Trauma
- Aneurysm
What does the pulmonary artery look like on CTPA?
The upside down Y one
What are the 4 steps in reporting a fracture on radiograph?
- Which bone (and where in the bone)
- Joint involvement (intra/extra articular)
- Direction of fracture?
- Transverse
- Oblique
- Spiral
- Longitudinal - Displacement? - does the cortex meet?
What do you call a fracture that has fragmented into several pieces?
Comminuted
What do you call a distal transverse radial fracture in an elderly patient? What is this due to?
Colles fracture - due to osteoporosis
Where is the trapezium (carpal) in relation to other anatomical landmarks?
The base of the radius
On a shoulder radiograph an anterior dislocation would move what landmark?
Coracoid process (part of scapula - more proximal)
On a shoulder radiograph a posterior dislocation would move what landmark?
Acromion (also part of scapula) (distal)
When bones that are rings (or form rings) break, where do they break?
Always break in two places
What are examples of bones that form rings in the body?
Fibula and tibia
Ulnar and radius
Pelvis
Vertebrae
On AXR can you always see the small bowel?
No, can’t always see, there is fluid in there
Where is the gas in the bowel in AXR?
The Colon (transverse and sigmoid)
What are the relevant sizes of the bowel in cm’s? How can you quickly compare this?
Small bowel = 3cm
Colon = 6cm
Cecum = 9cm
Quickly compare with the height of the vertebrae (3cm)
Abdo XR interpretation steps?
Name
Date
Projection:
- PA
- AP
Bowel gas
- Stomach
- Small Bowel (may not see, but would be central with the rings that go all the way around)
- Large bowel (Peripheral position - Sigmoid and colon are flexible and vary in position, has haustra - Arrowheads)
- Caecum
Soft tissue
- Liver
- Spleen (LUQ - superior to kidney)
- Lung bases
- Psoas
- Kidneys
- Bladder
Bones
Calcification and artefact
- Anything stuck in there
- Calcified arteries
- Gallstones (if calcium - 20%)
Initial management of Small Bowel Obstruction?
NG tube
Fluids
Pain control
What is the significance of a competent and incompetent ileocaecal valve on AXR?
In large bowel obstruction if the pt has a competent ileocaecal valve there will be no small bowel obstruction and these patients will present earlier.
If the valve is incompetent there will be small bowel obstruction and the pt will present later.
If you see pancreatic calcification in AXR, what does this likely mean?
Chronic pancreatitis
Coffee bean sign on AXR most likely means what?
Sigmoid volvulus
What are the IBD signs you see on AXR?
Toxic megacolon
Thumbprinting
Ischaemic
What are the three types of colitis?
Infective
Inflammatory
Ischaemic
What is the NICE guidance on who needs a CT Head?
CT head immediately
- GCS <13 on initial assessment
- GCS <15 2 hours after injury
- Suspected open/depressed skull fracture
- Basal skull fracture (panda eyes CSF leakage from ear/nose)
- Post traumatic seizure
- Focal neurological deficit
- >1 episodes of vomiting
CT head within 8 Hrs of injury (if they have LOC/amnesia)
- >65
- Bleeding/clotting disorders
- Dangerous mechanism of injury
- >30mins retrograde amnesia of events before head injury
Within 8 hours anyway:
- Pt on warfarin
Reporting structure for CT head?
Name/age/date
Normal/Abnormal
intra (within brain) or extra axial
Location
Grew/white matter (opposite on CT)
Attenuation
- Black (low attenuation)
- White (high attenuation)
Affect on adjacent structures
How can you classify brain haemorrhages?
Extra-axial
- SAH
- Extradural
- Sub-Dural
Intra-axial
- Lobar
- Contusions
How does old blood show on CT Head?
Dark - low attenuation
If the blood on a CT head is white (high attenuation) is the bleed old or young?
Young
If there is bleed (normally fresh bleed) in the sulci, what type of haemorrhage is it?
SAH
If there is mixed old and fresh blood on a CT Head, what is the likely pathology?
Subdural that is rebleeding
What CT head changes does a SAH commonly show?
Hydrocephalus
Central high attentuation star
Blood in Sulci
Two common causes of a SAH?
Trauma
Aneurysm
On a CTPA what shape is the Pulmonary Artery in?
Upside down Y
