Abstract
Fluorodeoxyglucose (FDG) is the most commonly utilized positron emission tomography (PET) tracer and has demonstrated utility in oncology. FDG-PET imaging is extremely useful in diagnosing, staging, and monitoring response to treatment in a variety of cancers. However, PET imaging is limited in its ability to assign molecular abnormalities to specific anatomical structures. This limitation has been recently overcome by the appearance of PET/CT system. This image fusion has tremendous potential because it combines the most sensitive 'functional image' with the highest resolution 'structural image'. This fusion imaging is essential for accurate diagnosis of molecular disorders.
CT angiography (CTA) offers a valuable alternative for the diagnosis of coronary artery disease (CAD). However, it is well established that a comprehensive assessment of CAD requires not only morphologic information but also 'functional information'. Thus, assessment of the functional relevance of coronary stenosis, such as stress myocardial perfusion single photon emission computed tomography (SPECT), is extremely important to guide further decisions about revascularization. In the present study, 3D fused cardiac SPECT/CT images were generated. The additional utility of fused imaging was obtained in the diagnosis of culprit arteries in patients with multi-vessel disease, along with a functional assessment of vessels with heavy calcification on CTA. This fusion imaging provides useful diagnostic information on the function relevance of coronary artery lesions.
