I sn't that title just a piece of nonsense designed to catch your attention? Why should you breathe in the inert noble gas knowing that you need oxygen instead? Maybe an aging singer could mix some helium to his breath when his voice does not meet the high notes anyrnore. Of course, divers exchange nitrogen with helium since even under pressure it hardly dissolves in the blood and hence averts ...

The goal of this study was to determine a T1-weighted magnetic resonance (MR) imaging sequence appropriate for evaluating the longitudinal relaxation effect of superparamagnetic iron oxide (ferumoxides) in a phantom study. An agarose phantom that included various concentrations of ferumoxides (0 - 0.5 mmol/l in 0.05 mmol/l increments) was examined for six types of T1-weighted imaging sequences ...

OBJECTIVE A relationship between T1ρ relaxation time and glycosaminoglycan (GAG) content has been demonstrated in chemically degraded bovine cartilage, but has not been demonstrated with quantitative biochemistry in human cartilage. A relationship has also been established between T2 relaxation time in cartilage and osteoarthritis (OA) severity. We hypothesized that T1ρ relaxation time would be...

Introduction Quantitative MR techniques have become increasingly on demand in human brain imaging. In particular, accurate mapping of the longitudinal relaxation time, T1, and water content, M0, is of prime interest pushing the development of techniques with high spatial resolution and short experimental durations. The current most efficient method for obtaining T1 maps is based on acquiring tw...

Introduction: The longitudinal relaxation time (T1) of tissues plays an important role both as a contrast mechanism for anatomical imaging and as a disease marker. To date, several techniques have been proposed for measuring it (e.g. [1,2]). Most of them are based on modeling monoexponential behavior for individual voxels. Even though brain tissue is considered to exhibit monoexponential T1 beh...

The 'H spin-lattice relaxation time, linewidth, second moment of 'H NMR absorption, differential thermal analysis, and differential scanning calorimetry of methylammonium tetrabromocadomate(II) crystals were studied. A new solid phase was found between 482 K and the melting point (493 K). The 'H NMR measurements revealed the presence of overall reorientation of methylammonium cations in this ph...

For the first time, magnetic resonance imaging (MRI) with hyperpolarized (hp) krypton-83 (83Kr) has become available. The relaxation of the nuclear spin of 83Kr atoms (I = 9/2) is driven by quadrupolar interactions during brief adsorption periods on surrounding material interfaces. Experiments in model systems reveal that the longitudinal relaxation of hp 83Kr gas strongly depends on the chemic...

PURPOSE The longitudinal relaxation rate (R1 ) measured in vivo depends on the local microstructural properties of the tissue, such as macromolecular, iron, and water content. Here, we use whole brain multiparametric in vivo data and a general linear relaxometry model to describe the dependence of R1 on these components. We explore a) the validity of having a single fixed set of model coefficie...

The renormalization group formalism was applied to calculate the spinlattice relaxation rate T 1 of a well-defined magnetic moment in the neighborhood of a spin degenerate Anderson impurity. In the Kondo regime, T 1 in function of the temperature T presents a peak at the Kondo temperature Tk; for T ≪ Tk, the system behaves as a heavy Fermy liquid, with an enhanced density of states, which incre...