background dynamic contrast-enhanced magnetic resonance imaging (dce - mri) has been widely used in the management of breast cancer, and its diagnostic value in breast imaging has been demonstrated. there have only been a few reports regarding the usefulness of pre-contrast imaging. knowledge about clinically significant findings of preoperative, pre-contrast t1 and t2 mr images will allow more...

Retinal ganglion cells projecting to the monkey lateral geniculate nucleus fall into two classes: those projecting to the magnocellular layers of the nucleus (M cells) have a higher contrast gain to luminance patterns at photopic levels of retinal illumination than those projecting to the parvocellular layers (P cells). We report here that this difference in luminance contrast gain between M an...

Background Phase-contrast imaging normally uses gradient-echoes with RF spoiling and phase-encode rewinding with a fixed dephasing by gradient “spoiler” pulses in each TR (time between RF pulses) studied in detail (1) where effective artifact suppression in magnitude images required >≈ 8PI dephasing over the slice thickness, with >≈ 2PI dephasing over an FE pixel. However, the effectiveness of ...

Methods A large gel phantom was used to assess phase offset in through-plane phase contrast images in x (left to right), y (anterior to posterior) and z directions at the isocenter and in positions ±40 mm and ±80 mm away from the isocenter. Repeated measures were averaged and fit to linear regressions. Phase correction was validated in human study for the assessment of aorta and pulmonary arter...

Variation in aposematic signals was once predicted to be rare, yet recent years it has become increasingly well documented. Despite increases the frequency with which polytypism and polymorphism have been suggested occur, population-wide variance is rarely quantified. We comprehensively sampled a subpopulation of poison frog Oophaga sylvatica , species polytypic across its distribution also sho...

background: butterworth, gaussian, hamming, hanning, and parzen are commonly used spect filters during filtered back-projection (fbp) reconstruction, which greatly affect the quality and size accuracy of image. materials and methods: this study involved a cardiac phantom in which 1.10 cm thick cold defect was inserted into its myocardium wall and filled with 4.0 μci/ml (0.148 mbq/ml) 99mtc conc...