PURPOSE The use of the low-energy high-resolution (LEHR) collimator for lymphoscintigraphy causes the appearance of star-shaped artifacts at injection sites. The aim of this study was to confirm whether the lower resolution of the low- to medium-energy general-purpose (LMEGP) collimator is compensated by decrease in the degree of septal penetration and the reduction in star-shaped artifacts. ...

Compressive spectral imaging systems can reliably capture multispectral data using far fewer measurements than traditional scanning techniques. In this paper, a thin-film patterned filter array-based compressive spectral imager is demonstrated, including its optical design and implementation. The use of a patterned filter array entails a single-step three-dimensional spatial-spectral coding on ...

The Leksell Gamma Knife is a standard radiosurgical tool for treating brain lesions by directing beams of gamma radiation to a specific region. The diameter of the gamma beams is confined by collimator systems and available collimator sizes are 4, 8, 14 and 18 mm. The reduction in dose rate for each collimator helmet is called the output factor (OPF). Experimental determination of OPFs is diffi...

UNLABELLED The main objective of this work was the development of a skew-slit collimator for small-animal SPECT to replace the state-of-the-art multipinhole collimator. METHODS A pinhole forms a cone-beam imaging geometry. If the collimator rotates around the object in a circular orbit, the projection measurements acquired by the cone-beam imaging geometry are incomplete and not enough for ar...

A plasma spectrometer design based on advances in lithography and microchip stacking technologies is described. A series of curved plate energy analyzers, with an integrated collimator, is etched into a silicon wafer. Tests of spectrometer elements, the energy analyzer and collimator, were performed with a 5 keV electron beam. The measured collimator transmission and energy selectivity were in ...

In this paper, we propose a CdZnTe rotating and spinning gamma camera attached with a slit collimator. This imaging system acquires convergent planar integrals of a radioactive distribution. Two analytical image reconstruction algorithms are proposed. Preliminary phantom studies show that our small CdZnTe camera with a slit collimator outperforms a larger NaI(Tl) camera with a pinhole collimato...

High-resolution multicolor printing based on pixelated optical nanostructures is of great importance for promoting advances in color display science. So far, most of the work in this field has been focused on achieving static colors, limiting many potential applications. This inevitably calls for the development of dynamic color displays with advanced and innovative functionalities. In this Let...

UNLABELLED A dedicated stationary cardiac single-photon emission computed tomography (SPECT) system with a novel segmented slant-hole collimator has been developed. The goal of this paper is to calibrate this new imaging geometry with a point source. METHODS Unlike the commercially available dedicated cardiac SPECT systems, which are specialized and can be used only to image the heart, our pr...

PURPOSE To develop a collimator trajectory optimization paradigm for volumetric modulated arc therapy (VMAT) and evaluate this technique in paraspinal stereotactic body radiation therapy (SBRT). METHOD AND MATERIALS We propose a novel VMAT paradigm, Coll-VMAT, which integrates collimator rotation with synchronized gantry rotation, multileaf collimator (MLC) motion, and dose-rate modulation. A...