What is an aortic intimal flap?

Aortic dissection is a tear in the aortic intima that enables blood to force its way between the other layers of the vessel wall, forming an intimal flap that divides the aorta into a true and false lumen.

What is a dissection flap of the aorta?

An aortic dissection, or tear in the aorta, typically occurs when the inner layer of the artery’s wall weakens. If left untreated, the tear can enlarge. When this happens, blood can pass through the tear into the middle layer of the wall, causing the layers to separate from one another, or dissect.

What can mimic aortic dissection?

The origin of the aortic arch arteries may mimic aortic dissection. The walls of the adjacent arterial branches may simulate an intimal flap but can be identified on subsequent images (,,,Fig 7). The left brachiocephalic vein usually courses anterior to the supraaortic branches of the aortic arch.

Which of the following radiologic findings on CXR is most suggestive of a dissecting aortic aneurysm?

Mediastinal widening is the most common plain radiographic finding in aortic dissection; it is noted in 80% of patients (see image below).

Can EKG detect aortic dissection?

An electrocardiogram (ECG) may show complications of dissection, including a heart attack. The chest x-ray may show an enlarged aorta. However, both the ECG and chest x-ray may be completely normal in aortic dissection and cannot diagnose or exclude aortic dissection.

Which MRI pulse sequence is best suited for evaluation of aortic dissection?

4D flow MRI Hemodynamic quantification appears to be the major advantage of MRI over other imaging modalities in chronic aortic dissection. Encoding of all three spatial directions of a volumetric data set utilizing 3D velocity-encoded cine MRI relative to the cardiac cycle, is commonly referred to as 4D flow MRI (59).

How are false lumens identified in aortic dissection?

An essential part of the assessment of aortic dissection is identifying the true lumen, as the placement of an endoluminal stent-graft in the false lumen can have dire consequences. Distinguishing between the two is often straightforward, but in some instances, no clear continuation of one lumen with a normal artery can be identified.

How is MR angiography used to diagnose aortic dissection?

Three-dimensional contrast-enhanced MR angiography with postprocessing is a fast, accurate, and noninvasive technique for the diagnosis and classification of aortic dissection. It is helpful in designing therapeutic protocols for aortic dissection and may provide accurate 3D anatomic information for surgical and endovascular treatment.

What is the normal size of the descending aorta?

The aorta tapers distally, with the normal descending aorta always smaller in caliber than the ascending aorta in healthy individuals. The proximal descending aorta is considered abnormal when it exceeds 2.63 cm, and the distal descending aorta is considered abnormal when it exceeds 2.43 cm in diameter [ 7, 8 ].

Which is thicker chronic dissection flaps or acute flaps?

Chronic dissection flaps are often thicker and straighter than those seen in acute dissections 3. The CTA radiology report should include at least: