CMR lives up to its potential

The blueprint for cardiovascular MR in clinical use has existed since the 1980s, when pioneers like radiologist Dr. Charles Higgins and cardiologist Dr. Gerald Pohost recognized that MR could become a powerful instrument for cardiac imaging.

They sought a versatile tool. While the diagnosis of coronary artery disease would be the rock on which cardiac MR imaging would be based, its applications would address many heart conditions.

The blueprint anticipated that cardiac MR would provide evaluations of congenital heart disease, cardiomyopathy, arrhythmogenic dysplasia, valvular disease, and pulmonary hypertension. Although they remained a dream for most of cardiac MR's history, MR-guided cardiac interventions have long been considered an important aspect of the modality's potential influence on cardiology.

Realizing these dreams has not been easy. Poor temporal resolution was a stumbling block until more powerful MR scanners, multichannel parallel image processing, and better pulse sequences were introduced. With those innovations at hand, researchers are now moving swiftly to build a set of applications based on the original blueprint.

The 2004 meeting of the Society for Cardiovascular Magnetic Resonance reflected that movement. The three-day conference in Barcelona, Spain, will be remembered for plenary sessions that delved into CMR's increasingly varied clinical utility and for scientific inquiries that are boosting the user-friendliness of proven clinical procedures. Highlights included:

• Duke University's work on a comprehensive examination for coronary artery disease based on wall motion, perfusion, and late enhancement that outperforms stress-rest SPECT;

• Papers from Duke documenting that a quick visual examination of perfusion studies of suspected CAD is not as efficacious as time-consuming quantitative analysis, but it still produces results good enough to justify its adoption;

• Broader applications of late-enhancement MR to diagnose myocarditis, establish a diagnostic link between congestive heart failure and CAD, and guide radio-frequency ablations of myocardial fibrosis that triggers tachyarrhythmia;

• A new consensus concerning the relevance of vulnerable plaque detection in the treatment of atherosclerosis and agreement that plaque burden, monitored with CMR, may be more important;

• Mainstream applications for diagnosing and evaluating congenital heart disease and new evidence confirming the danger of exposing children to ionizing radiation; and

• Rapid progress at the University of Aachen in Germany and elsewhere in the development of MR-guided interventional cardiac procedures, including advancements in catheter navigation and artifact-free MR coronary artery stent design.

Clinician interest in cardiovascular MR was reflected in a 19% increase in professional registration compared with the 2003 conference, according to scientific program director Dr. Stefan Neubauer. Of 909 physicians and technologists in attendance, slightly more than half were Europeans.

Seventy percent of physician registrants were cardiologists, and 30% were radiologists. Seven of 10 physicians who perform CMR in the field are cardiologists.

The quantity and quality of scientific exhibits improved, according to Neubauer. Despite new review criteria that resulted in a 30% rejection rate, nearly 1000 papers and posters were accepted.

"CMR has reached a level of maturity that was clearly unthinkable just a few years ago," Neubauer said.