What is CTA in medical terms?

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In a patient’s journal, you might come across the abbreviation CTA. This can mean one of two things. It can stand for Computed tomography angiography or Clear to auscultate.

In general, the two terms are not confused. When used in a section detailing findings in a physical examination, it refers to the lungs being clear to auscultation.

If discussed in context with imaging results or blood vessels, it refers to computed tomography angiography. This is a common type of imaging test to asses blood vessels.

What is Computed tomography angiography?

Computed tomography angiography is an imaging technique used to visualize blood vessels in the body. It is done by combining imaging with a CT scan with a contrast dye injected into the blood vessel.

Ca CT scan is a type of X-ray machine that takes many pictures from different angles. It then uses computer technology to combine these into cross-sectional images of the object/area scanned.

The contrast dye is typically an iodine-based and is injected into the blood vessels. The iodine absorbs a lot of the radiation, which makes it lighter on the picture. 

The dye can be used in all types of CT scans to enhance tissue contrast and resolution. In CTA, it is used in a way that enhances the blood vessels, both arteries, and veins.

When is Computed tomography angiography used?

As you might have figured, a CTA is used when you want to investigate the blood vessels. More specifically, you can use it to find blockages, aneurysms (ballooning of vessel wall), dissections (tear in the vessel wall) and stenosis/narrowing of a blood vessel.

These changes can appear anywhere on the vessels in the body. Some of the changes tend to occur in certain places, which can cause disease.

Coronary CT angiography

One such place is the coronary arteries who tend to suffer from stenosis/narrowing. Because these blood vessels supply the heart muscle, it can be harmful. Luckily, it can be easily detected with a CTA visualizing the coronary arteries.

Aorta

The aorta and other branching great vessels are prone to aneurysms and dissection. This can both be detected with a CTA.

Pulmonary arteries

CTA is frequently used to examine the pulmonary arteries. This is because they are associated with what is known as pulmonary embolization. This is a condition in which there is a blood clot ion the pulmonary arteries. Depending on its size, it can be bearly noticeable to life-threatening in a matter of minutes.

Because of the potential severity of the condition, CTA’s have become the imaging technique of choice to diagnose/rule out pulmonary embolization.

Renal arteries

The renal arteries are the blood vessels supplying the kidneys. In rare cases, hypertension is caused by a narrowing/stenosis of a renal artery. In this case, it can be detected by performing a CTA on the renal arteries.

Cerebral/brain arteries

A stroke is an event where an area of the brain has its blood supply disturbed. This can be due to a blockage of an artery, as well as hemorrhage. Both of these can be detected with a CTA. That being said, the magnetic resonance angiography is the imaging modality of choice for the brain and its blood vessels.

Peripheral arteries

Over time, most arteries in the body become stiffer and narrow. This is especially true in patients that smoke. Often, the blood vessels in the legs are affected to the point that blood supply to the lower leg is decreased. When this is suspected, it can readily be detected with a CTA.

Also, CTA’s can reveal other types of blood vessel damage in the periphery, such as in trauma cases or due to surgical complications. 

What does clear to auscultate mean?

Clear to auscultate is a phrase that you can find in a summary of a respiratory examination. It means that the lungs have clear breathing sounds when examined using a stethoscope (auscultated). 

A respiratory examination is a type of physical examination that is performed on patients who complain of respiratory symptoms. This can be shortness of breath, coughing or chest pain.

The examination has 4 steps, inspection, palpation, percussion and auscultation. Upon auscultation, different types of sounds can be heard that can indicate disease.

Wheezing

Wheezing sounds can be heard as musical, sometimes, high pitched sounds when auscultating the lung. They can be heard on inspiration and expiration. It typically caused by narrowing of the airways, which can occur in cases of asthma and emphysema.

Ronchi

It can be heard as a low-pitched rumbling upon inspiration and expiration. It can often be heard more clearly towards the center of the lungs. This is because it is typically a result of viscous fluid in the airways.

Crackles

Can be described as the sound of popping bubble wrap. They can be described as fine and course, depending on their loudness and pitch. Both are a result of sound collapsed alveoli (air sacs in the lungs), that snap open due to increased air pressure during inspiration. 

It most typically occurs when there is more fluid in the lung tissue and air sacs. This can occur in case of pneumonia or congestive heart failure.

Stridor

Characterized as a high-pitched sound caused by turbulent airflow in the larynx/throat, or bronchial tree/airway. Most commonly caused by narrowing/obstruction of the airways. It is typically caused by a foreign body or be due to croup (toddlers), epiglottitis and anaphylaxis.

One typical example is when someone swallows their food to quickly and it gets stuck in the throat. If big enough, it will lie in the esophagus and compress the airways, causing stridor.

Prolonged expiration

This is not a specific sound, although it is commonly associated with a wheezing sound. This can indicate a narrowing of the airways that are typical in asthma and COPD patients.

If a patient is clear to auscultation it means that the examiner can hear any of the sounds discussed above. This is a good thing and makes it less likely that there is a problem with the lungs.

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