Watershed cerebral infarction due to massive pulmonary embolism

Case contributed by Mohamed Saber


Diabetic ketoacidosis with a disturbing level of consciousness

Patient Data

Age: 40 years
Gender: Female

Normal CT brain with no abnormlaity.

1 day later, the patient developed hypoxemia and right-sided weakness

CT pulmonary angiography


CT study shows massive pulmonary embolism with bilateral intravascular filling defects significantly compromising vascular lumen seen involving distal main pulmonary arteries and bilateral upper and lower lobar & segmental arteries. Evidence of right heart strain with enlarged right atrium & ventricle and interventricular septal bowing to the left. Bilateral pulmonary multiple wedge-shaped subpleural infarcts.

Newly developed left cerebral hemisphere multiple hypodense lesions seen at the parieto-occipital and fronto-parietal parafalcine region associated with effacement of related cortical sulci consistent with cerebral infarction suspected to be "watershed infarcts" along border zones between MCA/PCA and ACA/MCA respectively.

Further CT cerebral angiography was done to exclude arterial or venous occlusion.

CT angiography shows no arterial or venous stenosis or occlusion.

Case Discussion

Watershed infarcts occur at the border between cerebral vascular territories where the cerebral tissue is distant from the arterial supply and most affected by hypotension and hypoperfusion. Massive pulmonary emboli may be the leading cause of watershed infarcts due to hypotension and low cardiac output. If any new neurological symptoms in embolic patients, this possibility should be considered.

How to use cases

You can use Radiopaedia cases in a variety of ways to help you learn and teach.

Creating your own cases is easy.

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.