INTRODUCTION This work reports observations of T2* relaxation in human knee cartilage explants under ultrashort echo time (UTE) acquisitions in vitro. The objective of this study was to determine the number and distribution of T2* components. We hypothesize that the three major constituents of articular cartilage extracellular matrix (water, collagen, and proteoglycan) contribute to the existen...

Introduction The sampling distribution of a T statistic is well established when the statistic is based on observations taken from a multivariate normal population (MVN). With known parameters, the sampling distribution is always a chi-square distribution. In a Phase I operation with unknown parameters, where outliers need to be detected, the distribution of the T statistic is a beta distributi...

In this article, we induced acute changes in extracellular volume fraction in skeletal muscle tissue and compared the sensitivity of a standard 1H T2 imaging method with different 23Na-NMR spectroscopy parameters within acquisition times compatible with clinical investigations. First, we analyzed the effect of a short ischemia on the sodium distribution in the skeletal muscle. Then, the lower l...

BACKGROUND Although previous studies have helped define the natural history of Duchenne muscular dystrophy (DMD)-associated cardiomyopathy, the myocardial pathobiology associated with functional impairment in DMD is not yet known.The objective of this study was to assess the distribution of transverse relaxation time (T2) in the left ventricle (LV) of DMD patients, and to determine the associat...

Let μ be a measure with support on the unit circle and n ≥ 1, β > 0. The associated circular β ensemble involves a probability distribution of the form P β (μ; t1, t2, ..., tn) = C |V (t1, t2, ..., tn)| β dμ (t1) ...dμ (tn) , where C is a normalization constant, and V (t1, t2, ..., tn) = ∏ 1≤i<j≤n (tj − ti) . We explicitly evaluate the m−point correlation functions when μ is replaced by a discr...

PURPOSE To assess the transferability of the magnetic resonance imaging (MRI) multislice multiecho T2(*) technique for global and segmental measurement of iron overload in thalassemia patients. MATERIALS AND METHODS Multiecho T2(*) sequences were installed on six MRI scanners. Five healthy subjects (n = 30) were scanned at each site; five thalassemia major (TM) patients were scanned at the re...

Background T2 values are related to the tissue water content, providing useful diagnostic information in cardiac diseases, especially in acute states such as myocardial infarction (MI). Visualization of edema, its regional distribution, and extent in acute and chronic heart disease may be useful as a diagnostic tool and help in guiding treatment in the patients with heart disease. Recently, ede...

The deuterium decoupled, proton nuclear magnetic resonance spectrum of a sample of diphenylmethane-d3 dissolved in a nematic liquid crystalline solvent has been analyzed to yield a set of dipolar couplings, Di j . These have been used to test models for the conformational distribution generated by rotation about the two ring-CH2 bonds through angles t1 and t2 . Conformational distributions, par...

In carcinogenicity experiments with animals where the tumor is not palpable it is common to observe only the time of death of the animal, the cause of death (the tumor or another independent cause, as sacrifice) and whether the tumor was present at the time of death. These last two indicator variables are evaluated after an autopsy. Defining the non-negative variables T1 (time of tumor onset), ...