MRI Head


  • T2 (transverse relaxation time constant) = water/CSF is white
  • T1 (longitudinal relaxation time constant) = water/CSF is black
  • PD image – the effects of T1 and T12 are eliminated so the intensity of the signal depends on the density of protons in the tissue.
  • FSE (fast spin echo): allows rapid image acquisition, thereby minimising movement artifact
  • Fat suppressed images: useful for imaging bony structures
  • FLAIR (fluid attenuated inversion recovery): eliminates signal from CSF -> sensitive to oedema and inflammation
  • DWI (diffusion weighted image) + Apparent Diffusion Coefficient (ADC): can distinguish vasogenic oedema from cytotoxic oedema
  • gadolinium contrast: doesn’t normally cross the BBB but in areas where there is BBB break down -> contrast will high light area.


Herpes Encephalitis

  • temporal and frontal lobe oedema
  • does not enhance with contrast

Multiple sclerosis

  • multiple white matter areas of increased intensity
  • spinal cord and cerebral

Chiari Malformation

  • cerebellar tonsils below the foramen magnum (at least 5mm)
  • narrow posterior cranial fossa
  • elongation of 4th ventricle
  • obstructive hydrocephalus
  • syringomyelia or hydromyelia


  • DWI: increased signal
  • DWI + ADC: reduced signal

Sagittal Sinus Thrombosis

  • CT: hyperdensity in the sinus (increased with contrast), empty delta sign
  • MRI venogram: abnormal flow

CCC 700 6

Critical Care


Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of three amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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