Developments in hybrid scanning

Abstract

Image registration has long been a vital tool in medical imaging, and nuclear cardiology is no exception. Frequently, more than one imaging procedure is used during evaluation of patients for cardiac disease. Coronary angiography is the gold standard for diagnosis of coronary artery stenosis; magnetic resonance imaging (MRI) is performed to determine gross anatomy and function, and single-photon emission computed tomography (SPECT) or positron emission computed tomography (PET) is used to evaluate myocardial perfusion. More recently coronary multislice CT has been added to the armentarium providing the opportunity for noninvasive coronary angiography and detection of coronary artery calcification. Knowing the coronary anatomy is not enough to decide the culprit lesion in the treatment of ischaemic heart disease. Knowledge of the physiology of the coronary artery disease by functional studies like PET and SPECT is crucial. Both anatomical and functional data are equally important. There is no doubt that the combination of the two modalities allow better decision making and an improved final outcome for the patient. Comparison of biplane angiography with myocardial perfusion SPECT and PET images has been a routine practice in reading rooms and cardiology offices since the introduction of the techniques. Countless conferences have been held where physicians debate how the findings of these two modalities relate to each other in individual patients. However, a significant difficulty has been that most of the registration occurred in the minds of physicians as they look at two separate images. In order to solve this problem integrated scanners have developed