Modern Cardiac Imaging: A Comparison of CT, MRI, and Interventional Radiology—An Expert Interview with Prof. Ralf Bauer

At the renowned RNS Group Practice in Wiesbaden, Prof. Dr. med. Ralf Bauer brings his outstanding expertise as a specialist in radiology to the field of non-invasive cardiac imaging diagnostics. With years of experience and a specialization in cardiac CT and cardiac MRI, he has played a key role in revolutionizing the diagnostic capabilities for heart disease. Even during his time at the Medical University of South Carolina in Charleston, Prof. Dr. Bauer focused on modern cardiac imaging and developed a deep understanding of its complex technologies.

Under his leadership, the RNS Group Practice uses state-of-the-art equipment such as dual-source CT and a highly advanced 1.5-Tesla MRI to make precise and non-invasive cardiac diagnoses. These technologies make it possible to diagnose heart disease without the need for an invasive cardiac catheterization, which is a significant relief for many patients. Prof. Dr. Bauer and his team thus offer a comprehensive and innovative solution for the early detection of heart disease and for making differentiated diagnoses.

In recent years, Prof. Dr. Bauer has not only published numerous international peer-reviewed articles but has also delivered expert lectures that underscore his expertise and commitment to medical research. Under his leadership, the RNS Group Practice has received DRG certification as a center for cardiovascular imaging—an accolade that confirms the high standard of medical care and the close interdisciplinary collaboration with partners in cardiology and cardiac surgery.

Thanks to this exceptional expertise and first-class technical equipment, the RNS Group Practice is a leading provider of cardiac imaging diagnostics in the Rhine-Main region and offers its patients state-of-the-art, precise, and, above all, minimally invasive diagnostics that help them receive optimal treatment. In an interview with Prof. Dr. Bauer, the editorial team of the Leading Medicine Guide learned more about the various imaging options.

Cardiac diagnostics has made enormous strides in recent years, and modern imaging techniques play a crucial role in this progress. Modern technologies such as CT and MRI enable precise and early diagnoses—often without invasive procedures. These techniques not only provide valuable insights into the structure and function of the heart but also open up new therapeutic approaches and treatment options. A comparison of these technologies highlights their different areas of application and advantages, which can be leveraged for the optimal treatment of cardiac patients.

Imaging plays a crucial role in the diagnosis of heart and vascular diseases and enables a precise assessment of potential health risks. 

Modern imaging techniques, such as cardiac CT, are becoming increasingly indispensable, particularly when cardiovascular disease is suspected. A cardiac CT scan is used particularly when diagnosing coronary artery disease. This condition, in which the coronary arteries are narrowed by plaque or calcifications, poses a significant risk of heart attacks. 

“When patients exhibit symptoms but a clinical examination does not yield a clear diagnosis, a cardiac CT scan can provide a detailed and non-invasive assessment of the coronary arteries. For symptoms such as chest tightness or shortness of breath during physical or emotional stress, a cardiac CT scan is recommended to check for risk factors such as plaque in the arteries (atherosclerosis), especially in patients who smoke, have high blood pressure and/or high cholesterol, or have a family history of cardiovascular disease or diabetes. Patients with a combination of these classic risk factors and the aforementioned symptoms are the primary target group. If a patient shows clear symptoms and signs of a heart attack, a cardiac CT scan is not helpful, as a cardiac catheterization must be performed quickly in such an emergency situation. Fortunately, these days we hardly ever have patients who arrive “too late.” “Public awareness is good today, so general awareness is more widespread, and people are much less hesitant to see their family doctor or treating internist,” said Prof. Dr. Bauer at the beginning of our conversation. 

A cardiac CT scan is an extremely precise method for assessing the risk of heart disease and future heart attacks. Especially in patients with an increased risk of cardiovascular disease—such as high blood pressure, diabetes, or a family history of the condition—a cardiac CT scan helps detect structural changes in the cardiovascular system at an early stage, even before symptoms appear. 

One of the main uses of a cardiac CT scan is to evaluate the coronary arteries, which are responsible for supplying blood to the heart. “With a cardiac CT scan, we can identify the full extent of plaque buildup in the coronary arteries. These plaques can narrow the vessels and obstruct blood flow, which can lead to an increased risk of heart attacks. If we don’t detect any plaque, that’s very good news, and the patient has a risk of nearly 0% of having a heart attack over the next ten years. If we do find deposits, we can further classify them based on their severity. If we see very severe deposits that result in narrowing, further tests such as a blood flow assessment or a cardiac catheterization with appropriate stent placement can be performed. Based on large-scale national and international studies, we know that patients who are on medication for more severe plaque buildup tend to adhere more closely to their preventive medication regimen. Initial studies have shown that patients without severe narrowing but who are recommended preventive drug therapy due to the poor condition of their coronary arteries adhere more conscientiously to this treatment once they have seen the condition of their vessels with their own eyes via a cardiac CT scan. “This is a secondary prophylactic effect,” explains Prof. Dr. Bauer, adding:

“The precision of the results depends heavily on the technology used. In our practice, we work with the best equipment and use a dual-source CT system, which is currently among the most advanced devices on the market. A dual-source CT uses two X-ray sources and two detectors to capture images in a very short time (66 milliseconds)—something no other CT scanner has been able to achieve to date. This technology makes it possible to produce high-resolution images of the heart, even in patients with rapid or irregular heartbeats. Thanks to the high frame rate of the dual-source CT, we can obtain clear and precise images of the coronary arteries and other cardiac structures even in these patients. Another outstanding feature of the dual-source CT is what is known as “X-ray contrast agent reduction,” which enables precise visualization of the arteries while minimizing radiation exposure. This is important not only for patient safety but also for repeat imaging to monitor changes in the cardiovascular system over extended periods of time. In May 2025, we will begin using the very latest generation of these CT scanners—a so-called photon-counting CT—which will allow us to capture even thinner and more precise images (up to 0.2 mm thick) along with further technical improvements. 

To undergo a cardiac CT scan, certain conditions must be met. One of the most important is that the patient being examined must have symptoms and risk factors such as those mentioned above (high blood pressure, high cholesterol, etc.). The decision is based on the so-called Marburg Heart Score, a clinical decision-making tool that helps physicians estimate the likelihood of coronary heart disease (CHD) in patients with chest pain. “In addition to the appropriate equipment, personal certification and proven qualifications are required to ensure a high standard of quality assurance,” Prof. Dr. Bauer emphasizes. 

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The Marburg Heart Score is a clinical tool for estimating the likelihood of coronary heart disease (CHD) in patients with chest pain. It evaluates five criteria: age (men ≥ 55, women ≥ 65), known vascular diseases, pain on exertion, suspicion of a cardiac cause, and whether the pain cannot be triggered by palpation. The score (0–5) classifies patients into three risk groups: low (0–2 points), moderate (3 points), or high probability (4–5 points) of CHD. The score facilitates decision-making in primary care but does not replace further diagnostic testing in unclear cases.

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Cardiac MRI is primarily used when specific heart conditions are suspected that require detailed images of the heart tissue, heart valves, or blood vessels. 

“While a cardiac CT scan is used for the early diagnosis of coronary artery disease, cardiac MRI is used for further diagnostic evaluation when plaque deposits are already present. A cardiac MRI can thus determine whether plaque deposits are already causing impaired blood flow, which is not always clear with a CT scan. Under stress conditions, MRI provides an excellent view of blood flow to the heart muscle and can therefore be a decisive factor in determining whether stent or bypass treatment is necessary. MRI can diagnose all diseases of the heart muscle itself, while a CT scan examines the arteries—the “fuel lines” of the heart, our engine. MRI reveals how well the heart is functioning and performing, making it well-suited for detecting myocarditis—inflammation of the heart muscle. MRI allows for a precise assessment of the inflamed tissue and helps, for example, to distinguish between acute and chronic forms of myocarditis. This is because there are a variety of viruses that can trigger myocarditis, and there are also genetic causes for heart muscle disease in which the heart thickens or becomes enlarged—cardiomyopathy. These conditions are quite common, and they must always be considered when initial heart failure is diagnosed, so MRI is becoming increasingly important here for determining the cause,” explains Prof. Dr. Bauer.

A cardiac MRI is also useful in assessing heart valve defects and heart valve diseases. By providing precise visualization of the valve structures and function, the severity of valve changes or defects can be better assessed, which is crucial when planning treatment or a potential surgery. In addition, cardiac MRI is frequently used to evaluate congenital heart defects in order to visualize anatomical abnormalities—such as a malformed heart valve or a hole in the heart wall—and to assess their impact on heart function. Last but not least, cardiac MRI is also used to monitor and evaluate patients after a heart attack to track the extent of damaged heart tissue and potential scarring. This is crucial for planning further therapeutic measures and for assessing the risk of future complications.

Highly Qualified Radiology and State-of-the-Art Diagnostics

For over 32 years, RNS has provided high-quality diagnostics and therapy, based on a broad academic foundation and many years of professional experience. The four partners, in particular, embody the practice’s medical expertise, complemented by memberships in professional associations, committees, and various teaching positions. The team of highly qualified radiologists undergoes continuous professional development to ensure they are always up to date with the latest technology and research. State-of-the-art imaging technologies are used to make precise diagnoses and ensure the highest standards in patient care and image quality. Specialized diagnostic services are available to interested patients at our locations in Wiesbaden, Bad Soden am Taunus, and Frankfurt am Main, enabling comprehensive radiological and radiation therapy care at the highest level.

“At our RNS group practice, we offer patient-centered, high-quality medical care using the latest technology. This is something we are committed to providing. We want to do things in medicine that others don’t do—and not just at an average level. That is precisely the mindset of the partners in this practice. And that is why we are creating the appropriate settings to live up to this standard of excellence at the university level, even within a privately run practice,” Prof. Dr. Bauer emphasizes emphatically, and with that, we conclude our conversation.

Thank you very much, Professor Dr. Bauer, for this important and positive contribution!