Perceived contrast, contrast detection thresholds and contrast discrimination thresholds were measured in the presence and absence of surrounding patterns of a similar spatio-temporal makeup. In the foveal retina we found that the perceived contrast of the central pattern was reduced by the presence of the contrast surrounds with the effect being greatest at low test contrast. Detection thresho...

conclusion fs t2 w and ce fs t1 w sequences of axial planes were the most useful sequences in determination of active sacroiliitis. therefore, in patients with renal failure or allergy to contrast media, fs t2 wi can be obtained to detect active sacroiliitis. objectives the aim of this retrospective study was to assess the value of different magnetic resonance imaging (mri) sequences in evaluat...

By identifying the effect of any parameter such as distance, attenuation and scattering on the Line Spread Function (LSF), one can compensate the quantitative and qualitative destructive effect of such parameters by deconvolution method. Using a 99mTC line source, this study was performed on a single head ADAC SPECT system operating in planar mode. Variation of FWTM and FWHM and LSFs as a...

Determination of normal gastric emptying time and small intestinal transit time are useful in detecting gastrointestinal motility disorders and partial obstructions of the pylorus or small intestine. This study was conducted to evaluate iodixanol as a contrast agent in the gastrointestinal tract in New Zealand White rabbit. Twelve clinically healthy adult rabbits were prepared and kept for two ...