The tools are ready, are we?

Excerpt

In this issue of the Journal of Nuclear Cardiology, Lee and colleagues elegantly review the recent advances in the instrumentations for nuclear cardiac imaging.1 Solid-state radiation detectors incorporating cadmium zinc telluride (CZT) become the detector of choice for dedicated cardiac imaging systems. CZT single-photon emission computed tomography (SPECT) has improved image quality and shortened acquisition time of myocardial perfusion imaging (MPI) thanks to its direct energy conversion mechanism, narrow energy resolution, and pixelated nature of electrical circuit. The measurement of absolute myocardial blood flow (MBF) as well as coronary flow reserve (CFR) using CZT SPECT is now under active investigation and is showing clinical feasibility. Multimodality imaging systems which hybridized SPECT and positron emission tomography (PET) with CT widened clinical application of cardiac imaging studies. Quantitative SPECT/CT provides additive information of coronary calcium burden, attenuation correction for both visual and quantitative assessment of myocardial perfusion, and enables quantification of myocardial blood flow and flow reserve. Cardiac PET is also an active progress. Adoption of silicon photomultipliers (SiPMs) leads to enhancements in image quality and count rates. The application of accurate time-of-flight (TOF) information reduced emission-transmission mismatch artifacts. Information of the extracted coronary arteries from CT angiography allows non-linear motion correction of PET plaque images. Replacement of photomultiplier tubes with semiconductor photosensors such as the avalanche photodiode (APD) and SiPM has made it possible to integrate PET with magnetic resonance (MR). PET/MR system is now clinically available in hybrid as well as parallel camera structure. …