Myocardial perfusion scintigraphy (single photon emission computed tomography, SPECT) and positron emission tomography (PET) are suitable for detecting myocardial perfusion disorders. A slightly radioactive substance (tracer) is administered at rest and under physical or drug-induced cardiac stress.
The regional distribution of the tracer in the myocardium allows imaging of ischemia or scarring of the left ventricular myocardium. In addition, the detected extent and precise localization of myocardial ischemia allow to define an optimal treatment strategy for each patient. PET examination offers higher resolution with lower radiation exposure than SPECT.
Cardiac MRI also allows visualization of myocardial perfusion, but a gadolinium-containing contrast agent is used instead of the radioactive tracer. Finally, stress echocardiography is also able to detect circulatory disturbances indirectly by wall motion disturbances occurring under stress.
Complementary to SPECT and PET, computed tomographic (CT) coronary angiography does not provide information on myocardial blood flow, but does visualize wall changes or stenoses of the coronary arteries. The spatial resolution of coronary CT has been continuously improved (currently 0.23 mm) and radiation exposure has been reduced (currently 0.6 mSv). The strength of cardiac CT lies in its negative predictive value.
Since the end of 2014, the latest technological innovation is available, namely an integrated PET/MR. which includes both a PET with the latest detector technology and a 3T MRI device. In addition to its use in neurology and oncology, it introduces combined PET/MR hybrid diagnostics. As in PET/CT hybrid diagnostics, PET/MR allows to further increase the diagnostic power in ischemia assessment, vitality diagnostics, cardiomyopathies and sarcoidosis.