Walnut kernel microbleed pattern

The walnut kernel microbleed pattern along with the starfield pattern and corpus callosum diffusion restriction appears to be the most important imaging markers of cerebral fat embolism 1, 2, 3.

In this pattern, there is a diffuse presence of round microbleeds (punctate focal hypointensities) of monotonous size in the subcortical white matter (involving but not limited to the U-fibers), internal capsule and the corpus callosum, mostly sparing the corona radiata and the non-subcortical centrum semiovale on T2* GRE or SWI images 1. The described pattern resembles the appearance of a walnut kernel.

It should be noted that similarly looking diffuse cerebral microbleeds have been reported in a number of other cases, mainly involving the critically ill, such as in patients receiving extracorporeal membrane oxygenation (ECMO), or in critically ill COVID-19 patients, but in these cases microhemorrhages appear to be more random in size and distribution 4, 5.

See also

Article information

rID: 88315
Section: Signs
Synonyms or Alternate Spellings:
  • CFE
  • WNK pattern

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Cases and figures

  • Cerebral fat embolism
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