Background: CT provides a lot of information about the aorta. It has many advantages over other modalities, as its ability to image the entire aorta, visualizing the lumen, wall, and periaortic regions. CT can rapidly acquire high-quality images, allowing early diagnosis of acute aortic syndromes. Imaging should extend from above the aortic arch to at least the aortoiliac bifurcation for a complete aortic examination. Aortic dissection is the most lethal disease affecting the aorta. Death occurs as a result of aortic rupture or visceral ischemia. CTA can clearly spotlight the site of the dissection and its extension, and also complications as branches compressions, pleural effusions, aortic rupture, and presence of aortic aneurysms. The non-contrasted images are useful for detection of intimal calcification, haemorrhage, hematomas, asset the lungs, and check for fluid effusions. The convexity of the intimal flap is usually toward the false lumen that surrounds the true lumen. The false lumen usually has slower flow and a larger diameter and may contain thrombi. At contrasted enhanced CTA, the true lumen is in continuation with the undissected portion of the aorta, and the FL may be also thrombosed. Differentiating between the false and true lumen is more difficult when the aortic root is involved, and in rare cases of intimal intussusception /circumferential dissection, which produce a circumferential flap with one lumen wrapped around the other lumen in the aortic arch. The inner lumen is usually the true lumen