Molecular SPECT Imaging: An Overview

Abstract

Molecular imaging has witnessed a tremendous change over the last decade. Growing interest and emphasis are placed on this specialized technology represented by developing new scanners, pharmaceutical drugs, diagnostic agents, new therapeutic regimens, and ultimately, significant improvement of patient health care. Single photon emission computed tomography (SPECT) and positron emission tomography (PET) have their signature on paving the way to molecular diagnostics and personalized medicine. The former will be the topic of the current paper where the authors address the current position of the molecular SPECT imaging among other imaging techniques, describing strengths and weaknesses, differences between SPECT and PET, and focusing on different SPECT designs and detection systems. Radiopharmaceutical compounds of clinical as well-preclinical interest have also been reviewed. Moreover, the last section covers several application, of μSPECT imaging in many areas of disease detection and diagnosis.

Figure 1

Spatial resolution across the clinical and preclinical SPECT and PET imaging scanners.

Figure 2

Invivo SPECT and SPECT/CT with ^99mTc-MDP in C57BL/6 mice (3 hrs after injection dose 120 MBq i.v.). Note the high uptake in glenohumeral, the hip, and the femorotibial joints as shown in the whole body mouse (a). In (b) and (c), upper and lower extremities are shown where SPECT and CT images are coregistered. The whole body fused SPECT and CT is shown in (d). Images were acquired with the Inveon system (Siemens Medical Solutions) using dual detectors each mounted with a 5-pinhole collimator. The pinhole aperture size was 1.0 mm.

Figure 3

Some commercial preclinical SPECT systems. (a) A preclinical hybrid PET/SPECT device, the VECTor (Image courtesy of MI Labs), (b) Triumph Trimodality scanner (courtesy of Gamma Medica), (c) NanoSPECT (courtesy of BioScan, Inc), and (d) Inveon system (courtesy of Siemens Medical Solution) with internal components demonstrated (courtesy of Siemens Medical Solution).