Clinical excellence in cardiac CT must begin with education

The cardiovascular community has witnessed historic changes in the way cardiovascular disease is evaluated. Recently, the greatest growth has been in cardiac CT to noninvasively diagnose coronary (Figure 1) and noncoronary cardiac disease (Figure 2).

Despite its clear advantages and broad-based support, CCT practice varies widely among imaging communities. Many early-adopting radiologists and cardiologists have developed active clinical services. Others are still waiting to see how the technology evolves, local politics progresses, and Medicare and Medicaid policies are further defined. As we are clearly still in the early phase of modern day CCT, it is key that all of those involved with CCT strive for clinical excellence in acquisition, interpretation, and reporting.

Excellence begins with physician and technologist education and training, as the ability to acquire and interpret CCT images with high quality is only as good as one's skill. Participants in training programs can be categorized into three groups: The first consists of those seeking to become familiar with the technology and clinical applications. Decisions have not yet been made in their group practices. The training program will provide more direct understanding, regardless of whether exploratory committees have been established. The second consists of those who understand the clinical utility of CCT and want to get credentialed in anticipation of their groups eventually offering the procedure. The third consists of physicians and technologists whose practices have decided to pursue a clinical service. These individuals require training immediately and often design an accelerated training schedule.

TRAINING PROCESS

The training process includes didactic lectures, static case review, and hands-on workstation case review. At present, training opportunities are available through academic centers, professional societies, educational organizations, workstation vendors, and private sector physician groups. Most programs offer courses remotely and have self-study CD-ROMs. Onsite training is also available (www.cvctraining.com). This is often ideal for groups whose travel logistics, cost limitations, and call schedules preclude remote training.

Each program typically includes several learning objectives:

• to understand CCT acquisitions, contrast medium delivery, and workstation principles;

• to understand CCT indications;

• to understand cardiac anatomy on 2D, 3D, and 4D workstation displays;

• to understand cardiac pathology and pathophysiology;

• to recognize cardiac pathology on CCT, including but not limited to coronary atherosclerotic disease;

• to develop a methodology for image analysis; and

• to develop an efficient reporting structure for CCT.

To ensure standardized skill and knowledge, the American College of Radiology and the American College of Cardiology have established credentialing requisites for radiology and cardiology practices.1,2 Most insurance carriers will not reimburse without documentation that physicians and practices have met these standards. Local forces lead many radiologists to target their training to meet both ACR and ACC requirements.

In the future, the Society for Cardiovascular Computed Tomography will take this standardization to the next level with the initiation of cardiovascular CT board certification.

One of the most critical learning objectives is developing an efficient methodology for rendering anatomy and interpreting cardiovascular disease on a workstation. This can be achieved only through hands-on training courses.

After reviewing the workstation features, trainees should review cardiovascular and noncardiovascular anatomy using 2D, 3D, and 4D visualization techniques. It is important to demonstrate the principles of each technique and emphasize their advantages and disadvantages.

Trainees are then ready to develop a logical approach to systematically analyzing cardiac and vascular structures and to optimize interpretation accuracy and efficiency. As opposed to catheter angiography, in which contrast is injected directly into the vascular structures or the cardiac chambers and 2D cardiovascular structures appear on a screen, interpretation of CCT requires the operator to actively engage the workstation to display anatomy. The operator must "seek out" the anatomy and generate renderings that can be interpreted.

This requirement applies not only to coronary arteries, but also to the pericardium, right and left cardiac chambers, valves, pulmonary arteries and veins, coronary veins, and thoracic aorta. Anatomic segments do not necessarily need to be viewed with each visualization technique. Rather, techniques are utilized based on the anatomic segment of interest, the specific goals of the operator, and the advantages of each technique. By employing this approach, the operator can swiftly interchange techniques. Each trainee should develop an order of preference for evaulating and reporting the coronary and imaged noncoronary structures. This approach also applies to display and interpretation of noncardiovascular structures included in the data set.

Hands-on workstation training programs should offer a balanced caseload that reflects real clinical practice. Trainees should first be shown normal cases of high image quality. Next, normal cases of adequate and poor image quality should be presented, so the trainee can recognize suboptimal enhancement, motion (cardiac, respiratory, and patient), streak artifact, blooming artifact, incorrect field-of-view selection, and other pitfalls that can limit interpretation of the coronary arteries. Later, high-quality cases with < 50%, 50% to 70%, > 70%, and occlusive native coronary atherosclerotic lesions should be presented and reviewed, preferably with correlation to catheter angiography. High-quality studies with stents and bypass grafts should be presented at this time.

As the patterns of disease become understood, similar cases of less robust image quality should be presented. Following this, CCT cases showing coronary anomalies and myocardial, pericardial, valvular, pulmonary arterial, pulmonary venous, and thoracic aortic disease should be reviewed. Common adult congenital heart disease cases should also be presented. Over subsequent days, trainees should see as many cases as possible, often in a random order. Once trainees are exposed to basic pathology and workstation use, repetition and discussion are vital to pattern recognition, establishing a fundamental base that trainees can then apply in their own imaging practices.

Hands-on workstation training programs have become known as the most sophisticated method for learning the advanced skills essential to performing and interpreting CCT.

Dr. Hellinger is an assistant professor of radiology and cardiology at the Children's Hospital of Philadelphia, University of Pennsylvania, and is director of cardiovascular imaging and the 3D laboratory for radiology. He can be reached at hellinger@email.chop.edu.

References

• Weinreb JC, Larson PA, Woodard PK, et al. American College of Radiology clinical statement on noninvasive cardiac imaging. Radiology 2005;235:723-727.

• Budoff MJ, Cohen MC, Garcia MJ, et al. ACCF/AHA Clinical competence statement on cardiac CT and MR. JACC 2005;46(2):383-402.