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Basilar artery thrombosis

Case contributed by Dr Ian Bickle


Admitted with low GCS. Right sided stroke?

Patient Data

Age: 60
Gender: Male


Subtle increased attenuation of the tip of the basilar artery (HU 50).

The remainder of the intracranial appearances are normal.  Ventricular system normal.

Annotated image

Hyperdense basilar artery (inside red circle)


Patiente admitted to ICU. 16 hours later unilateral pupil fixation.

Diffuse low attenuation of the midbrain, pons and brainstem as well as the whole of the cerebellum.

The 4th ventricle is effaced.  Mild hydrocephalus not present on the prior study.

Low attenuation in the left occipital lobe.

Dense basilar tip.

Case Discussion

In a patient admitted with a very low GCS requiring inbutation with no other reasonable clinical cause consider basilar artery thrombosis.

This can be a difficult 'call' as often even on routine scans in older patients the basilar artery can appear dense due to atherosclerotic disease.

With an in-situ basilar thrombosis, as in this case it is typically not overtly hyperdense as the clot has newly formed.  With a basilar tip thromboembolism it is classically more hyperdense and therefore noticeable on CT as the embolus has been formed for a longer period of time.

In this case less than a day later the end organ consequences are apparent as the whole posterior fossa has infarcted.


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Case information

rID: 53351
Published: 15th May 2017
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included

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