In medicine, the<unk>  or hyperdense<unk>  sign is an increased radiodensity of an<unk>  as seen on computer tomography (CT) scans, and is a radiologic sign of early ischemic stroke. In earlier studies of medical imaging in patients with strokes, it was the earliest sign of ischemic stroke in a significant minority of cases. Its appearance portends a poor prognosis for the patient. The sign has been observed in the middle cerebral<unk>  (MCA), posterior cerebral<unk>  (PCA), vertebral<unk> , and basilar<unk> ; these have been called the<unk>  MCA sign,<unk>  PCA sign,<unk>  vertebral<unk>  sign, and<unk>  basilar<unk>  sign, respectively. Rarely, a hypodense<unk>  sign can occur due to fat embolism.
Dense artery sign
Puddle sign
Bing's sign
Hot quadrate sign
Claybrook sign
Matchbox sign
Limbus sign
Terry Thomas sign