What should families know about cardiac imaging procedures like MRI, Echocardiograms and CT scans?
The three most common types of imaging that we do in cardiology are echocardiography, which is the most widely used tool; followed by MRI; and most recently cardiac CT. There are other ways to visualize the heart, like catheterizations, but they are invasive. An echo is basically a form of noninvasive cardiac imaging that uses ultrasound. It’s a different name for cardiac ultrasound. It’s been around now since the mid 1970s. It’s become an extension of the stethoscope. It provides images of blood vessels and blood flow. It’s entirely noninvasive and not associated with radiation. Done more than 25,000 times a year here.
Whenever there’s a concern that something is wrong with the heart, echo is being used to evaluate it. It’s basically the eyes of the cardiologist. So if you need to know what the heart looks like—structure, function—echo is the primary tool; it’s the first tool.
– Tal Geva, MD, pediatric and adult cardiologist and electrophysiologist
For diagnostic imaging, we’re trying to find out about a patient’s heart condition to get an accurate diagnosis because that diagnosis also has implications for the patient’s management, whether medications or procedures are necessary, and at another level of detail, it can provide a roadmap for performing those procedures. There are a number of tools we have in Cardiology to make diagnoses and a lot are based on picture taking or imaging. Those include echocardiology, MRI and computed tomography, or CT scans. MRI is just one of the tools we have to help look at the heart and blood vessels to help us make those diagnoses.
Your cardiologist is usually the one that sends for an MRI, maybe after consultation with one of the members of the cardiac imaging group. That particular test would provide extra information that would be beneficial to the patient.
For MRI, because the test involves going into a large a tunnel-like machine that’s open at both ends, parents wonder if their children will be claustrophobic. Most children are not claustrophobic, but as people get older they may become more sensitive to that. So we have a number of things to help make that process easier. That includes shortening exams. Patients can also listen to music, or they can watch a video through special MRI-compatible video goggles we can give them, and usually some of those things are able to help the patient through an examination. The other question is that sometimes patients want to know whether or not they will need to have an IV placed, and that depends on what the purpose of the MRI is—we may need to inject a contrast dye for the purpose of seeing the blood vessels, but sometimes we don’t need the contrast dye. The other question we get is about whether or not it’s safe to have the MRI. There are some types of devices or things that can be implanted in the body that are not safe to have an MRI with, and so we take special care to screen the patients before the MRI to make sure they don’t have any of these devices.
I tell patients that once they’re in the MRI scanner, they tend to get more comfortable the longer they are in there. I can also provide reassurance around the safety aspect of it. We put a lot of attention and care into trying to make that as safe an environment as possible. And with regard to the IV placement, we are able to numb the skin and we can use an air infuser, which puts the numbing medicine in without even inserting the needle. Those are all things that patients seem to find helpful.
It’s helpful for families to know that examinations take 45-60 minutes in duration, typically, and that we will take care of safety concerns ahead of time. And if they are concerned about whether or not they may need an IV, they can call ahead of time and ask us.
What’s nice about MRI is that it’s a safe imaging technique, so there’s no known harm of getting multiple examinations at this point. We tend to use that rather than computed tomography (CT), because CT uses X-ray exposure, which can have a negative effect over time. For some people, they may have MRIs on a yearly basis, whereas others may only need it once.
– Andy Powell, MD, pediatric cardiologist and cardiac imaging