A. Passalaqua

A comparative study of peripheral to central circulation delivery times between intraosseous and intravenous injection using a radionuclide technique in normovolemic and hypovolemic canines

Intraosseous infusion is considered a useful technique for administration of medications and fluids in emergency situations when peripheral intravascular access is unobtainable. This study examined the effectiveness of intraosseous infusion for delivery of substances to the central circulation. Central deliveries of a radionuclide tracer administered by the intraosseous and intravenous routes were evaluated during normovolemic and hypovolemic states. Intraosseous infusion achieved peripheral to central circulation transit times comparable to those achieved by the intravenous route. Analysis of variance revealed no statistically significant differences between the peripheral to central delivery times comparing intraosseous and intravenous administration. The results demonstrate that intraosseous infusion is a rapid and effective method of delivery to the central circulation and is an alternative method for intravascular access. This study also suggests that a radionuclide tracer is useful for the evaluation of transit times following intraosseous injection.

Evaluation of a CdZnTe dual-energy system

The purpose of the study is to optimize the input and the output parameters of a dual energy CdZnTe semiconductor detector for chest radiography. The optimal detector parameters were obtained by maximizing the figure of merit, defined as the ratio between the square of the signal-to- noise ratio and the absorbed dose, for chest radiography.

Contrast resolution study of CdZnTe detectors for medical imaging

The detected signal and noise contributions were measured and related to the radiation exposure and tube current tube setting. Furthermore, the detector contrast has been experimentally determined. The experimental results indicate that Cd1-xZnxTe detectors have high detector contrast resolution. Therefore, they appear to be very attractive for x-ray digital imaging applications.

Evaluation of a gas-microstrip dual-energy system

The use of a gas microstrip detector in dual-energy radiography for certain clinical applications is explored. Optimal conditions of this technology for digital chest radiography are presented. These optimal conditions were obtained via computer simulations. The gas microstrip detector shows promise for achieving high spatial resolution, high internal gain, low noise and through the use of dual-energy techniques, high contrast resolution.

Optimization of Cd 1–xZn xTe Detectors for Digital Radiography

In this study, measurements of the electrical and detection parameters of the Cd1-xZnxTe detectors, within the x-ray diagnostic energy range, have been performed with the aim of optimizing the image quality parameters of these solid-state-ionization detectors. Namely, the leakage current and system capacitance of the x-ray imaging system have been measured as they relate to signal parameters. Similarly, the detected signal and noise contributions were measured and related to the radiation exposure and tube current setting. Furthermore, the detector contrast has been experimentally determined. The experimental results indicate that Cd1-xZnxTe detectors have low leakage current, high resistivity, and high detector contrast resolution. Therefore, they appear to be very attractive for imaging applications with applications in x-ray digital radiography.

Ion-polar collisions in gas-filled KCD imaging detectors

A narrowing of the line spread function (LSF) has been observed when small amounts of low ionization potential polar dopant molecules were added to gas-filled high pressure kinestatic charge detector (KCD) for x-ray digital radiography. The LSF narrowing is attributed to different coexisting physical mechanisms. In this study, the impact of long-range dipole moment forces, associated with low ionization potential polar molecules, during ion-polars collisions, is investigated. Finally, this study is implemented with experimental examples.