1. Sectional Anatomy
Chest Vasculature

2. Objectives List vessels found in the thoracic region
Differentiate between heart chambers
Identify the locations of and relationships between chest vasculature
After completing this topic, you should be able to:
List vessels found in the thoracic region
Differentiate between heart chambers
Identify the locations of and relationships between chest vasculature

3. CT Chest Imaging
Scanning the chest requires identification of the heart chambers and vasculature. A technologist must be able to distinguish between vascular structures in the chest. Vessels appear bright white on a CT scan following the administration of intravenous iodinated contrast media. The rate of injection and volume of contrast administered is determined according to the selected CT protocol and diagnostic reason for performing the CT exam.

4. CT Chest Imaging
A chest CT scan begins with acquiring a scout image. Scan lines are selected to include all pertinent anatomy. Routine chest CT scans require imaging from above the lung apices through to the adrenal glands. Scan parameters may vary according to specific facility and radiologist determined protocols.

5. Subclavian
Arteries
This is an axial CT image scanning through the lung apex. You can see the left scapula and right humeral head demonstrating this is a superior slice in the upper thorax.
The red arrow indicates the right subclavian artery. The right subclavian artery originates from the brachiocephalic artery which is a vessel branching directly from the aortic arch.
The blue arrow points to the left subclavian artery. The left subclavian artery is one of the three major branches from the aortic arch. As the slices move more inferiorly, the aortic arch will be demonstrated.

6. Common Carotid Arteries
The common carotid arteries are major vessels originating from the chest. In this image, the red arrow demonstrates the right common carotid artery. The right common carotid artery branches from the brachiocephalic artery.
The blue arrow demonstrates the left common carotid artery. The left common carotid artery is a major branch off of the aortic arch.

7. Carotid & Subclavian Arteries
This image demonstrates vessels bright white following the injection of contrast. The red arrows mark the common carotid arteries whereas the blue arrows mark the subclavian arteries.
Other anatomy seen on this image include the scapulae posteriorly and clavicles anteriorly. A bright white streak is visible between the ribs on the right side of this image showing the contrast injection.

8. Aortic
Arch
Branches
There are three major vascular branches originating from the aortic arch. These vessels include the brachiocephalic artery labeled with a red arrow, the left common carotid artery labeled with a blue arrow, and the left subclavian artery labeled with a green arrow.
The right common carotid and right subclavian arteries were demonstrated more superiorly in the upper thorax. These vessels branch from the brachiocephalic artery.

9. SVC
The superior vena cava is formed when the right and left brachiocephalic veins merge together. In this image, the left brachiocephalic vein is labeled with the blue arrow. The left brachiocephalic vein arches over the three main branches off of the aortic arch when visualized in the axial plane. The red arrow is showing the SVC that is formed when these two veins join together.

10. SVC
&
Aortic Arch
In this image, the aortic arch is coming into view. The brachiocephalic, left common carotid, and left subclavian arteries are no longer visible as separate vessels. The left arrow demonstrates the aortic arch. In this image the superior vena cava is labeled with the red arrow.
Besides the major vessels visible in this image, a large black circular structure is pointed out with a green arrow. This is the trachea. Air filled structures appear darker on a CT image because there is less beam attenuation and more beam transmission due to a lower part density.

11. Pulmonary Trunk & Arteries
This image demonstrates the pulmonary trunk and pulmonary arteries opacified with the intravenous contrast media. The pulmonary arteries are the only arteries in the body that carry deoxygenated blood. The pulmonary arteries carry deoxygenated blood out of the heart to the lungs. Oxygenated blood will return back to the heart via the pulmonary veins.
When performing a CTA of the Chest to rule out pulmonary emboli, the pulmonary trunk and arteries will be imaged following a rapid injection of contrast media. A pulmonary embolus appears as a dark circle inside of the bright white pulmonary arteries. The radiologist calls this a filling defect inside of the pulmonary arteries. These clots prevent the contrast from filling the entire pulmonary artery and for this reason the radiologist describes this occurrence as a filling defect.

12. Aorta
&
SVC
Besides the visualization of the pulmonary trunk and arteries displayed in this image, the ascending aorta, descending aorta, and superior vena cava are also demonstrated. In this image the green area represents the superior vena cava, the red arrow shows the ascending aorta, and the blue arrow points to the descending aorta.
Other structures seen on this image are the right and left mainstem bronchi demonstrated as two oval black circles below the pulmonary arteries. Additionally, the small black circle seen below the mainstem bronchi is the esophagus.

13. Heart Chambers
On this image the heart chambers come into view. The green arrow demonstrates the right atrium. The superior vena cava seen on previous images empties into the right atrium. Directly under the sternum of this axial image is the right ventricle labeled with a blue arrow. Lastly, is the left atrium pointed out with the red arrow. The left atrium is the most posterior chamber of the heart.

14. Pulmonary
Veins
Besides demonstrating the heart chambers, the pulmonary veins are also labeled in this image. The right and left pulmonary veins are demonstrated as blue arrows on this image. The pulmonary veins are the only veins in the body carrying oxygenated blood. This oxygenated blood is taken from the lungs back to the heart through the left atrium. The left atrium is labeled as the green arrow on this image.

15. Heart Chambers
The four heart chambers are well demonstrated on this image. The blue arrow shows the right atrium. Directly under the sternum is the right ventricle displayed with the red arrow. The left ventricle is pointed out with the purple arrow and the green arrow identifies the left atrium.