[Current developments in SPECT/CT systems using 99mTc-radiopharmaceuticals].

The 3 foundations of nuclear medicine are radiation conscious personnel, specific radiopharmaceuticals and equipment. The trend in molecular radiopharmacy is to develop new radiopharmaceuticals targeting peptides and receptors. 99mTc-radiopharmaceuticals give important clinical and molecular information especially in endocrinology, oncology and cardiology. The basic equipment has relied on crystal scintillation detector gamma cameras and the obtained images represent organ function provided by the specific radiopharmaceutical. Gamma cameras for single emission computed tomography (SPECT) can be added to an X-ray computed tomography (CT) equipment to form a hybrid (SPECT/ CT). The system is coupled to computer algorithms and special software to acquire and process the separate studies and fuse the two images to give a 3-D image of organ function plus anatomy. The new semiconductor or solid state detectors are a big improvement in commercial hybrid scintillation cameras and micro-SPECT/CT. Fused images obtained with SPECT/CT have been very useful in almost all medical areas and play an important role in preclinical research. The aim of this work is to present the current status and future trends of SPECT/CT systems in the clinical practice of nuclear medicine using technetium-99m radiopharmaceuticals. The development of molecular, functional and genetic imaging tools aided by new technology and SPECT/CT image fusion will enhance accurate diagnoses, and understanding of molecular mechanisms of disease and their respective response to radiopharmaceutical therapy.