unmatched perfusion defect
Last reviewed 01/2018
An unmatched perfusion defect in a ventilation perfusion scan, i.e. a perfusion defect in the absence of any ventilation defect, is pathognomic of an early pulmonary embolism - within the first three days. If a chest radiograph has been performed, there may be radiological signs of embolism.
It is at this stage that there will be some reversiblity with anticoagulant therapy.