New Releases by Michael Poon

This book provides a carefully selected compilation of challenging cases representative of the situations and pathologies likely to be encountered when performing cardiovascular imaging using CT. The conditions covered include coronary artery disease, anomalous coronary arteries, congenital heart disease, coronary artery bypass grafts, infectious diseases, structural heart disease, tumors, and aortic pathology. The book also provides insights into various scanning techniques geared towards the pre-procedural use of cardiac CTA in patients undergoing atrial fibrillation ablation, thoracic endovascular aortic repair, or transcatheter aortic valve replacement. In addition, scanning techniques for some of the more difficult cases that a cardiac imager may encounter in practice are reviewed. All images are high-resolution reproductions, and subsequent cardiac catheterization images are included for cases in which obstructive coronary artery disease was revealed. Clinical Pearls in Diagnostic Cardiac Computed Tomographic Angiography is specifically designed to meet the needs of residents, fellows, and physicians who have an interest in cardiovascular CT.

Tungsten is one of the primary material candidates being investigated for use in the first-wall of a magnetic confinement fusion reactor. An ion accelerator was used to simulate the type of ion interaction that may occur at a plasma-facing material. Thermal desorption spectroscopy (TDS) was the primary tool used to analyze the effects of the irradiation. Secondary ion mass spectroscopy (SIMS) was used to determine the distribution of trapped D in the tungsten specimen. The tritium migration analysis program (TMAP) was used to simulate thermal desorption profiles from the D depth distributions. Fitting of the simulated thermal desorption profiles with the measured TDS results provided values of the D trap energies. Deuterium trapping in single crystal tungsten was studied as a function of the incident ion fluence, ion flux, irradiation temperature, irradiation history, and surface impurity levels during irradiation. The results show that deuterium was trapped at vacancies and voids. Two deuterium atoms could be trapped at a tungsten vacancy, with trapping energies of 1.4 eV and 1.2 eV for the first and second D atoms, respectively. In a tungsten void, D is trapped as atoms adsorbed on the inner walls of the void with a trap energy of 2.1 eV, or as D2 molecules inside the void with a trap energy of 1.2 eV. Deuterium trapping in polycrystalline tungsten was also studied as a function of the incident fluence, irradiation temperature, and irradiation history. Deuterium trapping in polycrystalline tungsten also occurs primarily at vacancies and voids with the same trap energies as in single crystal tungsten; however, the presence of grain boundaries promotes the formation of large surface blisters with high fluence irradiations at 500 K. In general, D trapping is greater in polycrystalline tungsten than in single crystal tungsten. To simulate mixed materials comprising of carbon (C) and tungsten, tungsten specimens were pre-irradiated with carbon ions prior to D irradiation. Deuterium trapping could be characterized by three regimes: (i) enhanced D retention in a graphitic film formed by the C+ irradiation; (ii) decreased D retention in a modified tungsten-carbon layer; and (iii) D retention in pure tungsten.