Page 140 - Registrar Orientation Manual 2016

Reference:
1257
Effective date:
7 July 2015
Expiry date:
6 July 2018
Page:
23 of 35
Title:
Imaging Guidelines
Type:
Clinical Guideline
Version:
02
Authorising initials:
Canadian CT Head Rules for Minor Head Injury
All patients with a head injury with any of these features (witnessed loss of consciousness, or definite
amnesia, or witnessed disorientation) requires a head CT if they have any one of the following: High risk (for neurological intervention):
• GCS <15 at 2 hours post injury
• suspected open or depressed skull fracture
• any sign of basal skull fracture
• vomiting ≥ two episodes
• age ≥ 65yrs
Medium risk (for brain injury on CT):
• Amnesia before impact of >30mins
• Dangerous mechanism:
o pedestrianstruckbymotorvehicle
o occupantejectedfrommotorvehicle
o fallfromheight>3feet(1metre)or5stairs
In addition to the above indications, consider a CT in any patient who has had a head injury if they are on anticoagulants or on a combination of antiplatelets even without any of witnessed loss of consciousness, or definite amnesia, or witnessed disorientation. Note a CT will not exclude delayed bleeding so consider continuing neuro-observations in these patients even if the initial CT is normal.
The ‘Choosing Wisely’ recommendations include:
Don’t request CT head scans in head injuries, unless indicated by a validated clinical decision rule
Avoid ordering a brain CT or brain MRI to evaluate an acute concussion unless there are progressive neurological symptoms, focal neurological findings on exam or there is concern for a skull fracture.
Don’t routinely obtain CT scanning of children with mild head injuries.
Incidentalomas
If imaging has shown an unexpected asymptomatic finding, for example a pituitary, adrenal or liver lesion or lung nodule, either:
• Radiology will suggest appropriate follow up based on agreed guidelines, or
• The findings and case should be discussed at the appropriate Radiology MDT conference
before further imaging is requested.
Clinical urgency: Follow–up imaging in asymptomatic cases can be performed as an outpatient.
Intracranial Haemorrhage
The Stroke Imaging Pathway in the Australian imaging guidelines recommends CT angiography or
MRA is performed if clinically indicated to assess the cerebral vasculature.
It can be difficult to interpret CTA or MRA images soon after a bleed, so if early intervention is not indicated, a delayed CT with contrast may be adequate to exclude an underlying mass lesion. Seek specialist advice from Neurosurgery or a neuroradiologist.
It is not usually necessary to further image frail elderly patients with a likely hypertensive bleed or bleeding from an amyloid angiopathy, and/or if intervention is not indicated.
Clinical urgency:
If reduced level of consciousness:
If on anticoagulants and progressing: Other suspected cases:
Immediate CT whatever the time 24 hour CT / 7 days a week
CT 8am to 10pm / 7 days a week