Interpretation COPY Flashcards
CT Head - Process
Demographics
Non-contrast // Contrast (only for vascular)
Work from OUT -> IN
- Soft Tissue swelling? asymmetry?
- Bone fracture
- Periphery? bleed, atrophy
- Paranchyma? hypo/hyperdense
- Ventricles? Symmetry
- Mid line shift??
What does atrophy look like on CT?
Obvious, pronounced sulci and gyri
Symmetrical left to right
May not be symmetrical front to back
e.g. fronto-temporal dementia only anterior
Who is at risk of subdural and why?
Elderly, alcholics
- More likely to fall
- Atrophied brain, cortical bridging veins are more stretched and easier to severe
Subdural: Appearance
Concave ‘sliver’ on brain periphery
May be hyperdense (acute bleed) or hypodense (chronic)
OR acute on chronic (hyper and hypo dense)
Subdural: Hx
Repeated falls
Fluctuating consciousness
Who gets extradurals and why?
Often younger patients
Trauma related as middle meningeal artery bleed
Extradural: Appearance
Convex ‘eggtradural’ on periphery
Hyperdense, acute blood (high pressure bleed)
Within suture lines (between skull and dura)
May be midline shift
Extradual Hx
Traumatic incident with lucid interval
Then LOC, decreased GCS
e.g. rugby player took blow to head, carried on playing, dropped dead in changing room after match.
Extradural Mx
A to E, senior, refer neurosurgeons
SAH Mx
A to E, senior, refer neurosurgeons
Hypodense Brain Tissue: Causes
Ischaemia
Oedema
Old bleed
Hyperdense Brain Tissue: Causes
Acute bleed
Tumour
Calcification (often choroid plexus in ventricles)
SAH Risk Factors
Family history
HTN
PCKD
How to tell if old blood OR ischaemia/oedema on CT?
Old bleed will be much more defined than ischamia/oedema
SAH on CT
Could be central area of hyperdensity in the circle of willis area
May be midline shift
What anticoagulant?
Arterial vs Venous clot
Arterial e.g stroke, MI
- Due to platelet aggregation
- Give antiplatelets: aspirin, clopidogrel, ticagrelor
Venous e.g. DVT, AF clots
- More to do with clotting factors and cascade
- Give warfarin, DOAC
Ischaemic Stroke on CT
Initial CT Head may be normal
— Primarly to rule out haemorrhage
CT head 2-3 days later will show ischamia
- Hypodense area in parenchyma
- Asymmetrical
- May be midline shift
Initial Ischaemic Stroke Management
A to E
NBM until pass swallow assessment
CT Head to rule out haemorrhage
Aspirin 300mg Oral/600mg PR if unsafe swallow
CALL STROKE TEAM
- Consultant will make decision RE thrombolysis
Stroke Medical Management
Aspirin 300mg for 14 days
then
Clopidogrel 75mg for life
Mx If CT head shows haemorrhagic stroke?
A to E
Swallow assessment and NBM
Refer neurosurgeons
DO NOT GIVE ASPIRIN
Definitive rx for Ischaemic stroke
Thrombolysis if <4.5 hours (Stroke consultant to decide)
NEW Rx:
<4 hours, possibly PCI for brain
= mechanical thromolectomy
- discuss with stroke
When is midline shift significant?
ALWAYS
there is no such thing as a minor midline shift!!!
Why would you do an AXR?
Obstruction (main)
Perf - but probably would do erect CXR, abdo CT instead
Good Xray?
Diagphragm -> hernial orifices
Should be able to see psoas muscle
- if not, ? AAA rupture
SBO?
Dilation <3cm Valvular coniventes (all the way across)
3, 6, 9 rule for bowel size
Small < 3cm
Trans. colon <6 cm
Caecum <9cm
LBO?
Haustra not all the way across
Signs of inflammation in LB
Usual cause?
Thumprinting
- thickened bowel wall
Lead pipe colon
- smooth, featureless
TMC
- Smooth, featureless, +++ size
- risk of perf
Cause = IBD
Cause of concurrent LBO and SBO?
Incompetent ileocaecal valve
Volvulus?
Sigmoid
- towards RUQ, coffee bean sign
- Common, elderly, rx with flatus tube
Caecal
- toward LUQ, rarer
Signs of perf?
Wrigler’s sign
- double wall sign, gas on inside and out of bowel
Common surgical clips?
RUQ, cholystectomy clips
ECG placement
4th intercostal space for V1
Ride Your Green Bike
R = RA, Y = LA, G = LF, B = RF
Rate?
Count complexes on rhythm strip
Rhythm?
Irregular = likely AF!
P waves
- Absent?
- Shape?
Absent = AF
Triangular + tall = p pulmonale
- indicative of large right atrium
- usually due to lung disease causing pulm. hypertension
Bifid = p mitrale
- indicative of large left atrium
- usually mitral valve regurg/stenosis
Axis?
Look at V1 and V3
LAD = leaving: +ve in V1, -ve in V3
RAD = reaching: -ve in V1, +ve in V3
PR interval?
- Normal?
- What does length indicate?
should be 3-5 small sq
< 3 = accessory pathway e.g. WPW
> 5 = heart block