Welcome back to topic Tuesday at Aortic Hope!
We hope that you have been having a wonderful start to your week so far. Today, we will be doing an additional segment on imaging.
Now that you are familiar with echocardiography and CT from our last couple of weeks, today, we will be discussing a lesser known imaging modality known as transesophageal echocardiography or TEE, which is also a another important way that we can detect aortic aneurysms or dissections. TEE uses a probe that enters a patient’s mouth and advanced along the esophagus. Because the esophagus runs parallel and close to the thoracic aorta, TEE gives high-resolution images of nearly the entire thoracic aorta.
In this diagram, the TEE probe is seen within the esophagus on the right and it noticeably nearby important structures such as the heart on its left and the aorta on its right, allowing high quality images to be obtained of structures involved in aortic disease.
Cleveland Clinic Journal of Medicine, 2000
A key advantage of TEE over CT and MRI is that it can be done quickly at the bedside in the emergency department, operating room, or intensive care unit. TEE also provides information about the functional status of the aortic valve, which is commonly involved in aortic dissections, and blood flow and any clots known as thrombus in the false lumen created by the dissection. TEE thus offers a rapid and relatively inexpensive way to diagnose aortic disease.
However, a major drawback include that is uncomfortable for the patient given the insertion of the probe deep into the esophagus and so it may require sedation.
One TEE, the typical features of aortic dissection are double lumen (true and false lumen) separated by a mobile membrane that can be seen to move back and forth with each heartbeat, and different flow patterns within the true and false lumens. Below is an image obtained from TEE with color doppler showing presence of a false lumen created by the dissection designated as “FL”, with “TL” as true lumen. (The red and blue is a function of doppler to indicate the direction of flow of blood).
Cleveland Clinic Journal of Medicine, 2000
And this is all that we have for you about TEE for aortic dissection and aneurysms. We hope it was helpful in describing why it is sometimes done as an option aside from CT or MRI. We hope you are enjoying these weekly posts and would love to have you join us again next week. Be safe and healthy, and happy! Until next week.
- Duc Giao