RESUMO
We have designed a new type of molecule with a noble gas (Ng = Kr and Xe) atom in a six-membered ring. Their structures and stability have been studied by density functional theory and by correlated electronic structure calculations. The results showed that the six-membered ring is planar with very short Ng-O and Ng-N polar covalent bonds. The calculated energy barriers for all the unimolecular dissociation pathways are higher than 20 and 35 kcal/mol for Ng = Kr and Xe, respectively. The current study suggests that these molecules and their derivatives might be synthesized and observable at cryogenic conditions.
RESUMO
BACKGROUND/PURPOSE: Clinical decision-making in coronary artery disease requires integrated information on myocardial viability and coronary arteries, and cross-modality registration could facilitate this process. The recent emergence of hybrid positron emission tomography (PET)/computed tomography (CT) allows acquisition of this information in one study session; however, clinically useful software capable of presenting three-dimensional (3D) fused images to assess the relationship between myocardium and coronary arteries is limited. METHODS: Patients with prior myocardial infarction were examined using electrocardiographically gated 18F-fluorodeoxyglucose PET and 16-slice CT. RESULTS: There were seven patients; mean age was 59 +/- 15 years and six were male. Using 3D reconstruction, coregistration and interactive display, the topographical relationship between myocardial viability and coronary arteries was clearly identified. CONCLUSION: We present a protocol to acquire CT coronary angiography and PET data and to visualize 3D fused images with an interactive visualization interface. This image coregistration is potentially useful to facilitate the process of image interpretation and decision-making.
