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...

ABSTRACT Background: Coherent scattering leads to diffraction effects and especially constructive interferences. Theseinterferences carry some information about the molecular structure of the tissue. As breast cancer isthe most widespread cancer in women, this project evaluated the application of small angleX-ray scattering (SAXS) for differentiation between normal and cancerous breast tissues....

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 ...

We report on the first experimental demonstration of Compton imaging of gamma rays with a single coaxial high-purity germanium (HPGe) detector. This imaging capability is realized by two-dimensional segmentation of the outside contact in combination with digital pulse-shape analysis, which enables to image gamma rays in 4p without employing a collimator. We are able to demonstrate the ability t...

Multi-slat prompt-gamma camera is a promising tool for range monitoring during proton therapy. We report the results of comprehensive simulation study analyzing precision which possible to reach with this in determination position distal edge Bragg peak. For first time we include optical photons. The beam (single pencil beam, 130 MeV, 10 ns bunch period, total 1·108 protons) interacting polymet...

We have measured deuteron elastic scattering cross sections at 110 MeV on C and Pb, and at 120 MeV on C and Ni, with the Texas ARM K500 cyclotron. The motivation for this experiment is that, except for some limited data above 200 MeV [1], there exists no elastic scattering data above 90 MeV. In order to calculate deuteron optical potentials in the energy range accessible by the K500 cyclotron, ...

In order to model photon attenuation and detector resolution variation as a depth-dependent convolution for efficient reconstruction of quantitative SPECT, a central-ray approximation is necessary. This work investigates the impact of the approximation upon reconstruction accuracy and computational efficiency. A patient chest CT image was acquired and converted into an object-specific attenuati...

Single photon emission computed tomography (SPECT) is based on the measurement of radiation emitted by a radiotracer injected into the patient. Because of photoelectric absorption and Compton scatter, the gamma photons are attenuated inside the body before arriving at the detector. A quantitative reconstruction must consider the attenuation, which is usually nonuniform. Novikov has derived an e...

A novel method for obtaining position resolved information simultaneously from an entire plane of a polycrystalline or amorphous sample using the diffracted radiation or fluorescence has been developed. It makes use of a microchannelplate as a collimator in front of a position sensitive detector (CCDcamera). Experiments may be performed either in transmission or in reflection geometry. In the f...