The study was undertaken to validate phantom-derived corrections for errors in collimation due to septal penetration or scatter, which vary with the size of the gastric region of interest (ROI). Six volunteers received 495 ml of 20% glucose labeled with both In-113m DTPA and Tc-99m DTPA. Gastric emptying of each nuclide was monitored by gamma camera as well as by periodic removal and reinstilla...

PURPOSE The combination of single photon emission computed tomography (SPECT) and computer tomography (CT) that incorporates iterative reconstruction algorithms with attenuation and scatter correction should facilitate accurate non-invasive quantitative imaging. Quantitative SPECT (QSPECT) may improve diagnostic ability and could be useful for many applications including dosimetry assessment. U...

The purpose of this study was to estimate the uncertainty in the dose distribution for the (125)I source STM1251, as measured with a radiophotoluminescent glass rod dosimeter and calculated using the Monte Carlo code EGS5 in geometry that included the source structure reported by Kirov et al. This was performed at a range of positions in and on a water phantom 18 cm in diameter and 16 cm in len...

The lead disc method is conventionally applied to measure the scatter fraction directly in the energy range of diagnostic X-rays. There are numerous reports of use of this method, but it is difficult to make lead discs with sufficient fabrication accuracy. In this paper, we newly propose an indirect measurement method using collimators instead. In our method, we measure the following two experi...

Compared to conventional attenuation imaging, Talbot-Lau X-ray grating interferometry applied within a polychromatic setup suffers from additional artifacts. Among those are beam hardening and dispersion effects due to the complex coupling of different physical effects involved in the image formation process. In computed tomography these effects lead to image degradation, such as cupping and st...

Epithelia and mesenchyme interact during various physiologic and pathologic processes. Scatter factor is a mesenchyme-derived cytokine that stimulates motility, proliferation, and morphogenesis of epithelia. Recent studies suggest that scatter factor and its receptor (c-met) mediate mesenchyme/epithelia signalling and even interconversion. In this mini-review, we will discuss how scatter factor...

Many clinical and research studies in nuclear medicine require quantitation of iodine-123 (123I) distribution for the determination of kinetics or localization. The objective of this study was to implement several reconstruction methods designed for single-photon emission computed tomography (SPECT) using 123I and to evaluate their performance in terms of quantitative accuracy, image artifacts,...

Title of dissertation: TASK SPECIFIC EVALUATION METHODOLOGY FOR CLINICAL FULL FIELD DIGITAL MAMMOGRAPHY Haimo Liu, Doctor of Philosophy, 2012 Dissertation directed by: Professor Iacovos Kyprianou Department of Bioengineering Purpose: The purpose of this dissertation is to evaluate the image quality of clinical Full Field Digital Mammography (FFDM) systems. This is done by evaluating image acqui...

The goal of this study was to determine the quantitative accuracy of our OSEM-APDI reconstruction method based on SPECT/CT imaging for Tc-99m, In-111, I-123, and I-131 isotopes. Phantom studies were performed on a SPECT/low-dose multislice CT system (Infinia-Hawkeye-4 slice, GE Healthcare) using clinical acquisition protocols. Two radioactive sources were centrally and peripherally placed insid...