A total of 159 patients with first-time clinical symptoms of cerebral ischemia were recruited. Contributions to the perfusion territory were visualized with territorial arterial spin-labeling magnetic resonance (MR) imaging. The anatomic features of the circle of Willis were evaluated with time-of-flight MR angiography. Perfusion territory contributions were compared among circle
of Willis variants by using the Cochran-Mantel-Haenszel test.
Results: The perfusion territory contributions to the deep-brain structures could be evaluated in 119 of 159 patients (75%). With a fetal-type circle of Willis find protocol (41 of 238 hemispheres; 17%), there was a contribution from the ipsilateral internal carotid artery to the thalamus in all 41 hemispheres (100%), compared with 96 of the 197 hemispheres (49%) without a fetal-type circle of Willis. In the 19 patients with a hypoplastic A1 segment, there was more often
a contribution of the contralateral internal carotid artery to the perfusion of the nucleus caudatus (10 of 19; 53%) and the nucleus lentiformis (5 of 19; 26%).
Conclusion: The perfusion territory contributions to deep-brain structures vary widely. These differences can be partly explained by variations in the anatomic features of the circle of Willis. (C)RSNA, 2010″
“We investigated the effects of laser wavelength on the atomic, ionic, and radiative emission from laser-produced TH-302 manufacturer tin plasmas. For generating plasmas, planar tin targets were excited using either high intensity neodymium-doped yttrium aluminum garnet (Nd:YAG, 1.06 mu m) or carbon dioxide (CO(2), 10.6 mu m) laser pulses; both are considered to be potential excitation lasers for an extreme ultraviolet (EUV) lithography laser-produced plasma light source. Various diagnostic tools were utilized for investigating ionic, neutral, and radiative emission from Sn plasmas including Faraday cup, witness plate in conjunction with x-ray photoelectron spectroscopy (XPS), https://www.selleckchem.com/products/beta-nicotinamide-mononucleotide.html EUV, and visible emission spectroscopy and photography. Atomic and ionic analysis showed that the amount of
debris emitted by the Nd: YAG generated plasmas was considerably higher than the CO(2) laser-produced plasmas. The angular distributions of both atomic and ionic debris were found to be more forward-centric for the 1.06 mu m generated plasma while being much more uniform for the 10.6 mu m heated plasma. EUV and visible emission images of the plasma also showed a forward-centric appearance for 1.06 mu m heated plasmas. The strength of excited neutral emission was considerably lower for the case of the 10.6 mu m plasma while the kinetic energies of ions debris were found to be much higher for CO(2) generated plasmas. Surface analysis of the craters created by the lasers showed that the mass ablation rate is 3.6 times higher for Nd:YAG laser generated plasmas compared to CO(2) generated plasmas at maximum EUV emission. (C) 2010 American Institute of Physics. [doi:10.1063/1.