High-attenuation crescent sign

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High attenuation crescent sign or hyperdense crescent sign is a radiologic sign indicating impending aortic rupture. [1] [2] It is seen as a curvilinear area paralleling the vessel wall of the aorta. [3] The hyperdense area is due to intramural or mural thrombus haemorrhage. The blood that dissects through mural thrombosis or wall of the aneurysm causes weakening of the wall. [4] This is of relatively high density compared to the psoas muscle in contrast-enhanced CT and greater than the aorta in non-contrast CT imaging. [5]

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Aortic dissection Injury to the innermost layer of the aorta

Aortic dissection (AD) occurs when an injury to the innermost layer of the aorta allows blood to flow between the layers of the aortic wall, forcing the layers apart. In most cases, this is associated with a sudden onset of severe chest or back pain, often described as "tearing" in character. Also, vomiting, sweating, and lightheadedness may occur. Other symptoms may result from decreased blood supply to other organs, such as stroke or mesenteric ischemia. Aortic dissection can quickly lead to death from insufficient blood flow to the heart or complete rupture of the aorta.

Aneurysm Bulge in the wall of a blood vessel

An aneurysm is an outward bulging, likened to a bubble or balloon, caused by a localized, abnormal, weak spot on a blood vessel wall. Aneurysms may be a result of a hereditary condition or an acquired disease. Aneurysms can also be a nidus for clot formation (thrombosis) and embolization. The word is from Greek: ἀνεύρυσμα, aneurysma, "dilation", from ἀνευρύνειν, aneurynein, "to dilate". As an aneurysm increases in size, the risk of rupture, which leads to uncontrolled bleeding, increases. Although they may occur in any blood vessel, particularly lethal examples include aneurysms of the Circle of Willis in the brain, aortic aneurysms affecting the thoracic aorta, and abdominal aortic aneurysms. Aneurysms can arise in the heart itself following a heart attack, including both ventricular and atrial septal aneurysms. There are congenital atrial septal aneurysms, a rare heart defect.

Interventional radiology

Interventional radiology (IR) is a medical subspecialty that performs various minimally-invasive procedures using medical imaging guidance, such as x-ray fluoroscopy, computed tomography, magnetic resonance imaging, or ultrasound. IR performs both diagnostic and therapeutic procedures through very small incisions or body orifices. Diagnostic IR procedures are those intended to help make a diagnosis or guide further medical treatment, and include image-guided biopsy of a tumor or injection of an imaging contrast agent into a hollow structure, such as a blood vessel or a duct. By contrast, therapeutic IR procedures provide direct treatment—they include catheter-based medicine delivery, medical device placement, and angioplasty of narrowed structures.

Vascular surgery

Vascular surgery is a surgical subspecialty in which diseases of the vascular system, or arteries, veins and lymphatic circulation, are managed by medical therapy, minimally-invasive catheter procedures, and surgical reconstruction. The specialty evolved from general and cardiac surgery, and includes treatment of the body's other major and essential veins and arteries. Open surgery techniques, as well as endovascular techniques are used to treat vascular diseases. The vascular surgeon is trained in the diagnosis and management of diseases affecting all parts of the vascular system excluding the coronaries and intracranial vasculature.

Bicuspid aortic valve Medical condition

Bicuspid aortic valve (BAV) is an inherited form of heart disease in which two of the leaflets of the aortic valve fuse during development in the womb resulting in a two-leaflet valve instead of the normal three-leaflet valve (tricuspid). BAV is the most common cause of heart disease present at birth and affects approximately 1.3% of adults. Normally, the mitral valve is the only bicuspid valve and this is situated between the heart's left atrium and left ventricle. Heart valves play a crucial role in ensuring the unidirectional flow of blood from the atrium to the ventricles, or from the ventricle to the aorta or pulmonary trunk.

Aortic aneurysm Notable enlargement of the aorta (heart artery)

An aortic aneurysm is an enlargement (dilatation) of the aorta to greater than 1.5 times normal size. They usually cause no symptoms except when ruptured. Occasionally, there may be abdominal, back, or leg pain.

Aneurysm of sinus of Valsalva Medical condition

Aneurysm of the aortic sinus, also known as the sinus of Valsalva, is a rare abnormality of the aorta, the largest artery in the body. The aorta normally has three small pouches that sit directly above the aortic valve, and an aneurysm of one of these sinuses is a thin-walled swelling. Aneurysms may affect the right (65–85%), non-coronary (10–30%), or rarely the left coronary sinus. These aneurysms may not cause any symptoms but if large can cause shortness of breath, palpitations or blackouts. Aortic sinus aneurysms can burst or rupture into adjacent cardiac chambers, which can lead to heart failure if untreated.

Abdominal aortic aneurysm Medical condition

Abdominal aortic aneurysm is a localized enlargement of the abdominal aorta such that the diameter is greater than 3 cm or more than 50% larger than normal. They usually cause no symptoms, except during rupture. Occasionally, abdominal, back, or leg pain may occur. Large aneurysms can sometimes be felt by pushing on the abdomen. Rupture may result in pain in the abdomen or back, low blood pressure, or loss of consciousness, and often results in death.

Thoracic aortic aneurysm Medical condition

A thoracic aortic aneurysm is an aortic aneurysm that presents primarily in the thorax.

Abdominal aorta

The abdominal aorta is the largest artery in the abdominal cavity. As part of the aorta, it is a direct continuation of the descending aorta.

Ascending aorta Part of the heart

The ascending aorta (AAo) is a portion of the aorta commencing at the upper part of the base of the left ventricle, on a level with the lower border of the third costal cartilage behind the left half of the sternum.

Hemoperitoneum is the presence of blood in the peritoneal cavity. The blood accumulates in the space between the inner lining of the abdominal wall and the internal abdominal organs. Hemoperitoneum is generally classified as a surgical emergency; in most cases, urgent laparotomy is needed to identify and control the source of the bleeding. In selected cases, careful observation may be permissible. The abdominal cavity is highly distensible and may easily hold greater than five liters of blood, or more than the entire circulating blood volume for an average-sized individual. Therefore, large-scale or rapid blood loss into the abdomen will reliably induce hemorrhagic shock and, if untreated, may rapidly lead to death.

Abdominal ultrasonography

Abdominal ultrasonography is a form of medical ultrasonography to visualise abdominal anatomical structures. It uses transmission and reflection of ultrasound waves to visualise internal organs through the abdominal wall. For this reason, the procedure is also called a transabdominal ultrasound, in contrast to endoscopic ultrasound, the latter combining ultrasound with endoscopy through visualize internal structures from within hollow organs.

Computed tomography angiography

Computed tomography angiography is a computed tomography technique used to visualize arterial and venous vessels throughout the body. Using contrast injected into the blood vessels, images are created to look for blockages, aneurysms, dissections, and stenosis. CTA can be used to visualize the vessels of the heart, the aorta and other large blood vessels, the lungs, the kidneys, the head and neck, and the arms and legs.

Traumatic aortic rupture Medical condition

Traumatic aortic rupture, also called traumatic aortic disruption or transection, is a condition in which the aorta, the largest artery in the body, is torn or ruptured as a result of trauma to the body. The condition is frequently fatal due to the profuse bleeding that results from the rupture. Since the aorta branches directly from the heart to supply blood to the rest of the body, the pressure within it is very great, and blood may be pumped out of a tear in the blood vessel very rapidly. This can quickly result in shock and death. Thus traumatic aortic rupture is a common killer in automotive accidents and other traumas, with up to 18% of deaths that occur in automobile collisions being related to the injury. In fact, aortic disruption due to blunt chest trauma is the second leading cause of injury death behind traumatic brain injury.

Endovascular aneurysm repair Surgery used to treat abdominal aortic aneurysm

Endovascular aneurysm repair (EVAR), is a type of minimally-invasive endovascular surgery used to treat pathology of the aorta, most commonly an abdominal aortic aneurysm (AAA). When used to treat thoracic aortic disease, the procedure is then specifically termed TEVAR for "thoracic endovascular aortic/aneurysm repair." The procedure involves the placement of an expandable stent graft within the aorta to treat aortic disease without operating directly on the aorta. In 2003, EVAR surpassed open aortic surgery as the most common technique for repair of AAA, and in 2010, EVAR accounted for 78% of all intact AAA repair in the United States.

Acute aortic syndrome (AAS) describes a range of severe, painful, potentially life-threatening abnormalities of the aorta. These include aortic dissection, intramural thrombus, and penetrating atherosclerotic aortic ulcer. AAS can be caused by a lesion on the wall of the aorta that involves the tunica media, often in the descending aorta. It is possible for AAS to lead to acute coronary syndrome. The term was introduced in 2001.

Aortic rupture Rupture or breakage of the aorta, the largest artery in the body

Aortic rupture is the rupture or breakage of the aorta, the largest artery in the body. Aortic rupture is a rare, extremely dangerous condition. The most common cause is an abdominal aortic aneurysm that has ruptured spontaneously. Aortic rupture is distinct from aortic dissection, which is a tear through the inner wall of the aorta that can block the flow of blood through the aorta to the heart or abdominal organs.

Open aortic surgery Surgical technique

Open aortic surgery (OAS), also known as open aortic repair (OAR), describes a technique whereby an abdominal, thoracic or retroperitoneal surgical incision is used to visualize and control the aorta for purposes of treatment. OAS is used to treat aneurysms of the abdominal and thoracic aorta, aortic dissection, acute aortic syndrome, and aortic ruptures. Aortobifemoral bypass is also used to treat atherosclerotic disease of the abdominal aorta below the level of the renal arteries. In 2003, OAS was surpassed by endovascular aneurysm repair (EVAR) as the most common technique for repairing abdominal aortic aneurysms in the United States. In OAS for aortic aneurysm, the aneurysmal portion of the aorta is replaced with a graft, usually made of dacron or PTFE.

Inflammatory aortic aneurysm Medical condition

Inflammatory aortic aneurysm (IAA), also known as Inflammatory abdominal aortic aneurysm (IAAA), is a type of abdominal aortic aneurysm (AAA) where the walls of the aneurysm become thick and inflamed. Similar to AAA, IAA occurs in the abdominal region. IAA is closely associated and believed to be a response to and extensive peri-aneurysmal fibrosis, which is the formation of excess fibrous connective tissue in an organ or tissue in a reparative or reactive process IAA accounts for 5-10% of aortic aneurysms. IAA occurs mainly in a population that is on average younger by 10 years than most AAA patients. Some common symptoms of IAA may include back pain, abdominal tenderness, fevers, weight loss or elevated Erythrocyte sedimentation rate (ESR) levels. Corticosteroids and other immunosuppressive drugs have been found to decrease symptoms and the degree of peri-aortic inflammation and fibrosis

References

  1. Lee, Chris; Lynch, Richard (1 July 2015). "High-attenuation crescent sign on computed tomography in acute abdominal aortic aneurysm". The American Journal of Emergency Medicine. 33 (7): 988.e1. doi:10.1016/j.ajem.2014.12.038. ISSN   0735-6757 . Retrieved 8 September 2021.
  2. Pang, Wenjing; Karol, Anne; Minault, Quentin; Veillon, Francis; Venkatasamy, Aina (1 January 2019). "The hyperdense crescent sign". Abdominal Radiology. 44 (1): 376–378. doi:10.1007/s00261-018-1697-7. ISSN   2366-0058 . Retrieved 8 September 2021.
  3. Gonsalves, Carin F. (1 April 1999). "The Hyperattenuating Crescent Sign". Radiology. 211 (1): 37–38. doi:10.1148/radiology.211.1.r99ap1137. ISSN   0033-8419 . Retrieved 8 September 2021.
  4. Iranpour, Pooya; Haseli, Sara (4 June 2018). "Crescent sign in abdominal aortic aneurysm". BMJ Case Reports. 2018. doi:10.1136/bcr-2018-225435. ISSN   1757-790X . Retrieved 8 September 2021.
  5. Iranpour, Pooya; Haseli, Sara (31 May 2018). "Crescent sign in abdominal aortic aneurysm". Case Reports. 2018: bcr. doi:10.1136/bcr-2018-225435. ISSN   1757-790X . Retrieved 8 September 2021.