Cardiovascular imaging is a visual specialty of great subtlety and beauty. To make a diagnosis, imagers must be attuned to minor flaws in a patient's well-being: unwelcome eddies in blood flow, a myocardium unable to quench its thirst for oxygen, a certain flabbiness or eccentricity in how the heart pumps.
Doppler ultrasound, radionuclide perfusion imaging, three-dimensional MR and CT angiography-all bring the cardiovascular system dramatically to life with splashes of color or surfaces sculpted into fine detail. Each can seem as much a work of art as a data-laden report on sickness and health. Indeed, the marriage of intellectual rigor and visual beauty is what draws many cardiovascular imagers to the profession.
It's worth noting, then, that a different kind of vision will be called on to answer some of the challenging questions in cardiovascular imaging today: What will the specialty look like in five years? Who will the imagers be and what tools will they use to reveal the hidden beauty of the heart and its intricate labyrinth of arteries, veins, and capillaries?
For decades, x-ray angiography, nuclear imaging, and ultrasound have been the mainstays. They have proved exceptionally useful for uncovering heart disease in seemingly healthy but high-risk people, putting a name to the anatomic and physiologic aberrations that cause chest pain or shortness of breath, and gauging the risk that lies ahead.
Today, these imaging methods are firmly entrenched and-at least in the heart and coronary arteries-are plied almost exclusively by cardiologists. Advances in MR and CT could shake things up dramatically, however. By offering the potential to replace with a single noninvasive exam what today takes two or three studies to accomplish, CT or MR could become very attractive to referring physicians and payers, not to mention patients.
MR and CT angiography have established a strong foothold in the peripheral arteries. Many observers believe it's only a matter of time before these modalities scale the technological hurdles necessary for noninvasive coronary angiography. And researchers are working to establish the ability of CT and MR to assess myocardial perfusion and function, thus posing a challenge to nuclear and echocardiographic methods.
The result could be marked shifts in referral patterns-in the kinds of imaging exams patients are referred for, and at least for the time being, the types of physicians they are referred to. Radiologists, who hold superior technical knowledge about cardiac MR and CT, shouldn't become too comfortable, however. Cardiologists are fully capable of mastering new imaging technologies, as nuclear cardiology and echocardiography clearly show, and they already "own" the patients.
Patients, too, could well influence the future of cardiac CT and MR. Witness the success of entrepreneurial imaging centers offering coronary calcium screening, which more often than not is paid for by the patients themselves. One researcher predicted that the worried well would line up around the block with wallets in hand for an exam that could, in one stop, screen for atherosclerotic plaque, reveal serious stenoses, and assess how efficiently the heart is functioning-assuming, that is, the test didn't involve poking a catheter into the groin.
Will CT and MR succeed in challenging conventional imaging techniques? If they do, might either come to dominate noninvasive cardiovascular imaging? No one seems sure. Imaging vendors are so certain that the territory will be shared, however, that they are reaching out to cardiologists and vascular surgeons, while hoping not to alienate radiologists in the process. At the same time, integrated cardiovascular institutes that bring together several specialties are springing up around the U.S., in an attempt to trump turf battles with collaboration. One thing is certain: However the political questions are answered, patients are sure to be grateful for any technology that enables a comprehensive cardiovascular exam with little more than the prick of an intravenous needle.
Ms. Carrington is a contributing editor to Diagnostic Imaging.
