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Targeting improved spatial resolution, a three-dimensional positron-emission-tomography (PET) scanner employing CdTe semiconductor detectors and using depth-of-interaction (DOI) information was developed, and its physical performance was evaluated. This PET scanner is the first to use semiconductor detectors dedicated to the human brain and head-and-neck region. Imaging performance of the scanner used for ^18F-fluorodeoxy glucose (FDG) scans of phantoms and human brains was evaluated. The gantry of the scanner has a 35.0-cm-diameter patient port, the trans-axial field of view (FOV) is 31.0 cm, and the axial FOV is 24.6 cm. The energy resolution averaged over all detector channels and timing resolution were 4.1% and 6.8 ns (each in FWHM), respectively. Spatial resolution measured at the center of FOV was 2.3-mm FWHM—which is one of the best resolutions achieved by human PET scanners. Noise-equivalent count ratio (NEC2R) has a maximum in the energy window of 390 to 540 keV and is 36 kcps/Bq/cm^3 at 3.7 kBq/cm^3. The sensitivity of the system according to NEMA 1994 was 25.9 cps/Bq/cm^3. Scatter fraction of the scanner is 37% for the energy window of 390 to 540 keV and 23% for 450 to 540 keV. Images of a hot-rod phantom and images of brain glucose metabolism show that the structural accuracy of the images obtained with the semiconductor PET scanner is higher than that possible with a conventional Bismuth Germanium Oxide (BGO) PET scanner. In addition, the developed scanner permits better delineation of the head-and-neck cancer. These results show that the semiconductor PET scanner will play a major role in the upcoming era of personalized medicine. [ABSTRACT FROM AUTHOR]

This study was performed to evaluate regional wall motion (WM) and wall thickening (WT) using gated myocardial perfusion single photon emission computed tomography (SPECT) and to determine their similarity and disparity in patients with coronary artery disease. A total of 44 patients underwent 1 day stress/rest (MIBI) gated SPECT. Commercially available quantitative analysis of gated SPECT (QGS) software was used to generate 3D surface display and cine-mode SPECT display. Left ventricle was divided into nine segments to score WM and WT from 0 (no abnormality) to 4 (severe abnormality) by six independent observers. Finally a mean score was calculated for each segment from the scores of six observers. There was fairly good correlation between WM and WT of individual segments ( r = 0.62, p < 0.0001). Concordance rate (|WM − WT| ≤ 1) was 85%. A large difference between WM and WT (WM − WT ≥ 2) was observed in 15 segments, including 12 segments with greater WM abnormalities and 3 segments with greater WT abnormalities (lateral and inferior walls). Greater WM abnormalities were most commonly observed in anteroseptal segments especially in post coronary artery bypass grafting patients. In conclusion, WM and WT showed similarity on QGS studies. However, these two parameters may be determined separately in gated SPECT studies for comprehensive and robust evaluation of the functional status of myocardium. Analyses based on WM assessment alone may lead to erroneous results especially in septal regions. [ABSTRACT FROM AUTHOR]

This study was performed to evaluate regional wall motion (WM) and wall thickening (WT) using gated myocardial perfusion single photon emission computed tomography (SPECT) and to determine their similarity and disparity in patients with coronary artery disease (CAD). A total of 44 patients underwent 1 day stress/rest (MIBI) gated SPECT. Commercially available quantitative analysis of gated SPECT (QGS) software was used to generate 3D surface display and cine-mode SPECT display. Left ventricle was divided into nine segments to score WM and WT from 0 (no abnormality) to 4 (severe abnormality) by six independent observers. Finally a mean score was calculated for each segment from the scores of six observers. There was fairly good correlation between WM and WT of individual segments ( r = 0.62, p < 0.0001). Concordance rate (|WM − WT|≤1) was 85%. A large difference between WM and WT (WM − WT≥2) was observed in 15 segments, including 12 segments with greater WM abnormalities and 3 segments with greater WT abnormalities (lateral and inferior walls). Greater WM abnormalities were most commonly observed in anteroseptal segments especially in post coronary artery bypass grafting (CABG) patients. In conclusion, WM and WT showed similarity on QGS studies. However, these two parameters may be determined separately in gated SPECT studies for comprehensive and robust evaluation of the functional status of myocardium. Analyses based on WM assessment alone may lead to erroneous results especially in septal regions. [ABSTRACT FROM AUTHOR]

The article presents abstracts on topics related to nuclear cardiology, including the impact of attenuation correction with computed tomography (CT) on myocardial perfusion imaging in a hybrid single photon emission computed tomography/computed tomography (SPECT/CT), the effect of rosiglitazone on myocardial glucose uptake in ischemic regions in patients with type 2 diabetes, as well as the relationship between plasma myeloperoxidase levels and ischemic response during stress nuclear perfusion imaging.