Module 6 - Trauma Flashcards
CXR findings of acute aortic injury
A: Apical cap
- non-specific finding may be seen in older patients, but in a context concerning for aortic injury
B: Irregular contour
- Indistinct border and irregular contour have been found to be some of the most common findings
C: Increased retrocardiac density
- Due to widened thoracic aorta layered behind
D:Mediastinal widening
- one of the most common findings in aortic dissection
E: Displacement of NG tube
- enlarging dissection flap or rupture causes the oesophagus to be displaced laterally to the right
Describe and justify imaging pathways for a patient presenting following minor and major trauma.
C spine XR: often time consuming, but can diagnose 85% of #
CXR: immediate diagnosis of life-threatening pneumothorax/haemothorax/aortic
PXR: immediate diagnosis of life-threatening
FAST: good sensitivity (100-250ml free fluid detectable), repeat with changes
CT: finds most injuries
Differentiate between imaging appearance and anatomical space of a subdural vs extradural haematoma
SUBDURAL
Between dura and arachnoid
Crescentic in shape, conforms to dural reflections
Does not respect sutures
EXTRADURAL
May be venous due to dural sinuses or middle meningeal artery
Typically biconvex, limited by sutures but not dural sinuses
When do chronic subdurals become isodense to brain?When are they isodense to CSF?
Density decreases with time such that it’s isodense to brain at 10-14 days
Isodense to CSF after 3-4 weeks
What are the MRI characteristics of DAI?
- small focal of blood breakdown at grey-white junction, corpus callosum and brainstem
- SWI: small foci of low signal intensity (black dots)
CT findings of shock
CAVA collapsed
small diameter aorta
hypoenhancing spleen and kidneys
hyperenhancing adrenals and small bowel wall
Hounsfield units for
- free fluid
- fresh blood
- clotted blood
- active extravasation
Evidence base for whole body CT scanning in trauma
Retrospective evidence to suggest that mortality is higher if not takent to CT scanner, including if they are haemodynamically unstable
Allows greater degree of diagnostic certainty
Does not delay definitive treatment
AAST Grading splenic injury
Which AAST splenic patients get angio? Which splenic injury patients get laparotomy?
Angio for AAST III and above
Laparotomy for diffusely peritonitic, unstable patients
AAST Liver injury grading
AAST Renal injury grading
New orleans criteria for Head CT
(7)
Age over 60
Headache
Vomiting
Drug or alcohol intoxication
Deficits in short-term memory
Physical evidence of trauma above the clavicles
Seizure
(for patients with GCS 15 only)
Canadian Head CT rules inclusion (4) and exclusion (3) criteria
Inclusion criteria
Patient has suffered minor head trauma with resultant:
loss of consciousness
GCS 13-15
confusion
amnesia after the event
Exclusion criteria
anticoagulant medication or bleeding disorder
age <16 years
seizure
Canadian Head CT high risk factors and low risk factors (5 each)
High risk factors
- GCS <15 two hours post injury
- suspected open skull fracture
- sign of base of skull fracture
- vomiting more than twice
- age >65 years
Medium risk factors
- amnesia post event >30 min
- dangerous mechanism of injury
- pedestrian struck by motor vehicle
- occupant ejected from motor vehicle
- fall from >3 feet or 5 stairs
MRI features of spinal cord injury
- T2 high signal intensity and appears white
- Focal T2 signal hyperintensities eg. “Owl Eye” - see picture for ischaemia
- DWI: increased signal intensity showing restricted diffusion
Differentiate between NMO (neuromyelitis optica) and MS on MRI/clinical features
MS - enhancing
Multiple cord lesions
Relatively short in superior-inferior extent
Usually only 1 vertebral body height
Posterolateral in the cord
NMO
Recurrent episodes of optic neuritis and spinal cord lesion
Extend over 3 bodies
Linear enhancement
Probe location and organs of interest for all FAST views
R Flank
- Mid-clavicular and posterior axillary lines through intercostal space (10th or 11th)
- See liver on left, kidney beneath liver
- Normal Morison’s pouch appears as white stripe
L Flank
- Posterior axillary line 8th or 9th intercostal space towards spleen and left kidney
Suprapubic
- Probe above pubic symphysis
- Retro-vesical space and pouch of douglas
- Reproductive age women may have false positives
- Empty bladder can hamper views
Cardiac views
- Flat to abdomen, aim towards left shoulder
- Shows all 4 chambers and pericardium
Thoracic views
- 3-4th intercostal space in mid-clavicular line
- Normal: lung sliding and comet tail artefacts
Limitations of FAST (6)
Cannot localise injury
Not for retroperitoneum
Difficult with obese, excessive bowel gas, subcut emphysema
Fluid <200ml missed
Old bleeds clot
No differentiation between fluids eg. Urine/ascites
vertebal injury instability crieria (4)
- If more than 1 vertebral column involvement
- Reduced or increased disc space height
- Facet joint widening
- Compression >25%
