We conduct TinyTim modeling of NICMOS camera 2 PSFs to assess limits to the accuracy of PSF subtraction imposed by color dependence, OTA focus breathing, and cold mask wiggling. The results suggest that effects of both cold mask wiggling and focus breathing can be described as a noise in a PSF-subtracted image, well above 20% of the PSF signal in narrow band filters, with a spatial scale of a f...

Several variants of CTLA-4 have been reported to be associated with susceptibility systemic lupus erythematosus (SLE); however, findings have been inconsistent across different populations. Using a case-control study design, we have investigated the role of CTLA-4 polymorphism at positions -1661 and -1722 on SLE susceptibility in our Chinese SLE population in central China's Hubei province. Sam...

OBJECTIVE To characterize the performance of the Biograph mCT PET/CT TrueV scanner with time of flight (TOF) and point spread function (PSF) modeling. MATERIAL AND METHODS The PET/CT scanner combines a 64-slice CT and PET scanner that incorporates in the reconstruction the TOF and PSF information. PET operating characteristics were evaluated according to the standard NEMA NU 2-2007, expanding...

BACKGROUND PET reconstruction incorporating spatially variant 3D Point Spread Function (PSF) improves contrast and image resolution. "Cardiac Motion Frozen" (CMF) processing eliminates the influence of cardiac motion in static summed images. We have evaluated the combined use of CMF- and PSF-based reconstruction for high-resolution cardiac PET. METHODS Static and 16-bin ECG-gated images of 20...

Institute of Biophysics and Biomedical Engineering, Faculty of Sciences, University of Lisbon, Lisbon, Portugal Hybrid MR-PET scans enable acquisition of both types of images within a session. Despite consistent subject positioning, image alignment can still be challenging. Functional MR images rely on echo-planar imaging (EPI) and present geometric distortions due to static B0 field inhomogene...

Prostacyclin (PGI2) synthesis by vascular endothelial cells (ECs) decreases in diabetic subjects, possibly leading to development of diabetic angiopathies including that in atherosclerosis. We identified a bioactive peptide, prostacyclin-stimulating factor (PSF), which stimulates PGI2 synthesis in cultured aortic ECs. Our previous studies demonstrated that PSF was predominantly expressed by art...