Conventional Cartesian non-diffusion pulse sequences acquire k-space in multiple excitations (a.k.a. shots). As the phase errors originating from motion during the diffusion preparation time are random in nature and large compared to the phase used to spatially encode the image, the use of multi-shot sequences with diffusion gradients is not straightforward, and in most cases severe image ghost...

We summarize and discuss a series of psychophysical studies on the effects of spatial covert attention on spatial resolution, our ability to discriminate fine patterns. Heightened resolution is beneficial in most, but not all, visual tasks. We show how endogenous attention (voluntary, goal driven) and exogenous attention (involuntary, stimulus driven) affect performance on a variety of tasks me...

We present a high-spatial-resolution subsurface microscopy technique that significantly increases the numerical aperture of a microscope without introducing an additional spherical aberration. Consequently, the diffraction-limited spatial resolution is improved beyond the limit of standard subsurface microscopy. By realizing a numerical aperture of 3.4, we experimentally demonstrate a lateral s...

Introduction: Electronic portal imaging devices (EPIDs) provide two- and three-dimensional planar and volumetric cone beam images to improve the accuracy of radiation treatment delivery. Periodic quality assurance (QA) of EPIDs is essential for dosimetric verification in radiotherapy. In this study, a QA program was implemented to evaluate the function of the EPID to be confident in applying co...

Introduction: Substantive amount of work has been done in modeling and analyzing the scintillation camera system processes including positioning and image formation. The goal of this work is to develop a framework for analyzing performance of nonlinear positioning methods upon construction of a mathematical model of the system. In this study, the photodetector array counts are ...