Aortic dissection CT: Difference between revisions
Jump to navigation
Jump to search
No edit summary |
No edit summary |
||
| Line 24: | Line 24: | ||
</div> | </div> | ||
===Advantages of CT=== | |||
*Readily available at most hospitals, even on an emergency basis. | |||
*Easy identification of intraluminal thrombus and pericardial effusions. | |||
*CT scanning with contrast has a reported sensitivity of 94% and a specificity of 87%. The accuracy of CT can be further improved with spiral CT and ultrafast CT (Electron beam CT). | |||
CT | ===Disadvantages of CT=== | ||
*The need for iodinated contrast material. | |||
*Inability to see the intimal flap in more than 75 % of patients. | |||
*Inability to diagnose the site of the intimal tear. | |||
*Assessment of coronary arteries and aortic incompetence is difficult with a CT. | |||
===Differentiating a true lumen from the false lumen=== | |||
*Beak sign: In the false lumen, there will be an acute angle between the dissection flap and the arterial wall. | *Beak sign: In the false lumen, there will be an acute angle between the dissection flap and the arterial wall. | ||
*Aortic cobwebs: In the false lumen, there may be fibroelastic bands. | *Aortic cobwebs: In the false lumen, there may be fibroelastic bands. | ||
| Line 34: | Line 41: | ||
*Diplaced intimal calcification: Usually faces the true lumen. | *Diplaced intimal calcification: Usually faces the true lumen. | ||
===Labeled CT images shown below are courtesy of Radswiki and copylefted:=== | |||
<div align="left"> | <div align="left"> | ||
Revision as of 16:53, 10 October 2012
|
Aortic dissection Microchapters |
|
Diagnosis |
|---|
|
Treatment |
|
Special Scenarios |
|
Case Studies |
|
|
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor-In-Chief: Cafer Zorkun, M.D., Ph.D. [2]
Overview
Computed tomography angiography
- Computed tomography angiography is a fast non-invasive test that will give an accurate three-dimensional view of the aorta. These images are produced by taking rapid thin cut slices of the chest and abdomen, and combining them in the computer to create cross-sectional slices.
- In order to delineate the aorta to the accuracy necessary to make the proper diagnosis, an iodinated contrast material is injected into a peripheral vein. Contrast is injected and the scan performed using a Bolus Tracking method. This is a type of scan timed to an injection, in order to capture the contrast as it enters the aorta.
- The scan will then follow the contrast as it flows though the vessel.
-
Aortic dissection Type Stanford A -
Aortic dissection Type Stanford A - '1 Aorta ascendens, true Lumen - 2 false Lumen - 3 Pulmonary artery - 4 Aorta descendens - 5 thoracic vertebra
-
Another example of Stanford A type dissection
Advantages of CT
- Readily available at most hospitals, even on an emergency basis.
- Easy identification of intraluminal thrombus and pericardial effusions.
- CT scanning with contrast has a reported sensitivity of 94% and a specificity of 87%. The accuracy of CT can be further improved with spiral CT and ultrafast CT (Electron beam CT).
Disadvantages of CT
- The need for iodinated contrast material.
- Inability to see the intimal flap in more than 75 % of patients.
- Inability to diagnose the site of the intimal tear.
- Assessment of coronary arteries and aortic incompetence is difficult with a CT.
Differentiating a true lumen from the false lumen
- Beak sign: In the false lumen, there will be an acute angle between the dissection flap and the arterial wall.
- Aortic cobwebs: In the false lumen, there may be fibroelastic bands.
- Size: False lumen is usually larger than the true lumen.
- Diplaced intimal calcification: Usually faces the true lumen.
Labeled CT images shown below are courtesy of Radswiki and copylefted:
