Noninvasive imaging for the diagnosis and management of myocardial ischemia

The past 10 years has seen a revolution in noninvasive cardiac imaging. UFCT and MRI can demonstrate cardiac anatomy in exquisite detail and have become our most accurate methods of measuring ventricular function. PET and MRS are giving insights into myocardial metabolism that were previously impossible in vivo. UFCT and MRI have also made progress in imaging the coronary arteries and bypass grafts. Although neither technique is in a position to rival coronary arteriography, the first steps have been made. Accurate quantification of coronary calcium is possible with UFCT and promises to be our most valuable noninvasive tool in the diagnosis and management of patients with asymptomatic disease. Myocardial perfusion has been assessed with 201TL imaging for years, but new radiopharmaceutical agents and advances in UFCT and contrast-enhanced MRI are likely to bring great improvements. Table 2 lists the current modalities and outlines their main advantages and disadvantages. Despite all this progress, there has been little change in clinical practice. Invasive procedures, i.e., cardiac catheterization or transesophageal echocardiography, are still being performed even when equivalent information can be obtained noninvasively. While limited availability may explain the scant use of PET and UFCT for cardiac imaging, in those centers where it is available, interest is still muted. The need to foster multidisciplinary interaction is real. If the benefits of this revolution are to be passed on to patients, there needs to be a greater willingness among physicians from different specialties to collaborate and to be more tolerant than has occurred in many centers to date. This will not only improve patient care but it will also provide an appropriate evaluation of new technologies. All are critical if we are to solve the continuing problems of ischemic heart disease.