August 3, 2009

CT Angiography "Spot Sign"

An above image panel shows an intracerebral hemorrhage (blue arrows) in the right frontal lobe on an unenhanced image; a spot sign (yellow arrow) on a CTA source image; puddling of contrast extravasation (red arrowheads and yellow arrow) on an enhanced image. Unenhanced follow-up CT 6 hours later shows hematoma expansion (blue arrows). The patient underwent hematoma evacuation. Also noted on these images is subdural and subarachnoid hemorrhage.

Intracerebral Hemorrhage: Facts
  • 10% - 30% of all stroke
  • Outcome worse than ischemic stroke, up to 50% mortality at 30 days
  • Causes: hypertension, amyloid angiopathy and anticoagulation
  • Pathomechanism - believed to be due to parenchymal microaneurysm with rupture
Outcome Predictors
  • Hematoma size
  • Hematoma expansion (definition: increase of 33-50% or absolute change in volume between 12.5 to 20 mL of hematoma). Known risks of expansion include antecedent warfarin use and ultra-early presentation
CT Angiography "Spot Sign"
  • Definition: one or more 1- to 2-mm foci of enhancement within the hematoma on CT angiography source images
  • On a routine enhanced CT scan, if there is an enlargement of contrast density - this is called "contrast extravasation"
  • The sign has been described in primary intracerebral hemorrhage; but it could be seen - and termed "spot sign mimics" in cases of secondary intracerebral hemorrhage (i.e. aneurysm, calcification, etc.)
  • Independent predictor of hematoma expansion
1. Goldstein JN, Fazen LE, Snider R, et al. Contrast extravasation on CT angiography predicts hematoma expansion in intracerebral hemorrhage. Neurology 2007;68:889-894.

2. Wada R, Aviv RI, Fox AJ, et al. CT angiography "spot sign" predicts hematoma expansion in acute intracerebral hemorrhage. Stroke 2007;38:1257-1262.

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