Department of Radiology

CT of the Chest

The Department of Radiology has assembled a guide to demystify the CT of the Chest. While the Chest CT images can seem complex to the uninitiated, if you can count to six and follow a few basic rules, it is actually pretty easy at least to make an intelligent stab at interpretation. The key is to orient yourself and then try to trace out the expected anatomy.

First-

Find the image with three major structures: the Aorta, SVC, and trachea. This is the level of the aortic arch. The aorta looks like a sausage at this level.

Second-

Let's go craniad.

• What are the three great vessels that arise from the aorta?
  Hint: Remember medical school anatomy? Look for the R. inominate artery, the L. common carotid, and the L. subclavian artery to replace the aorta (the sausage) just above the aortic arch. These vessels surround the trachea.
• Which two great veins form the SVC?
  At this level, the Right and Left Brachiocephalic veins lie anterolateral in the mediastinum.

Note: So far you've only had to count up to five structures.

Finally-

A little further craniad. Finally you have to count to six.

The only change here is that the R. inominate artery bifurcates to form the Right common carotid and subclavian arteries. These mirror their analogs on the left. All four surround the trachea.