Archive for the ‘CT Imaging Sign’ Category
Hyperattenuating Crescent Sign
Hyperattenuating Crescent Sign : is a CT sign of acute or impending rupture of abdominal aortic aneurysm.
Finding : A well-defined peripheral crescent of increased attenuation within the thrombus of a large abdominal aortic aneurysm.
This finding is best appreciated on unenhanced CT images. It represents an internal dissection of blood into either the peripheral thrombus or the aneurysm wall, a process that either causes or results from a loss in the ability of the thrombus to protect the aneurysm from rupture. It is one of the earliest and most specific imaging manifestations of the rupture process
Hyperdense MCA sign
Hyperdense MCA sign : It can be seen with acute thrombus formation. A hyperdense MCA sign is indicative of an impending large infarct and is of very poor prognosis. This is a very early CT finding of impending infarction. It should be noted, however, that there are other causes of a hyperdense MCA such as atherosclerotic calcifications.
Other early findings in an acute stroke include loss of the insular ribbon as well as hypodensity within the lentiform nucleus. Loss of the gray/white junction is also an early finding in acute infarction.
The region of infarction can be more accurately located by magnetic resonance imaging. Such findings include absence of the normal “flow void” as well as edema with loss of the gray/white junction.
Draped aorta sign
Draped aorta sign : An important CT imaging feature that may be seen in a contained rupture of an abdominal aortic aneurysm.
Findings : The posterior wall of the aorta either is not identifiable as distinct from adjacent structures or when it closely follows the contour of adjacent vertebral bodies.
