BACKGROUND Structural abnormalities of the common carotid artery (CCA), as assessed by ultrasound techniques, are related to cardiovascular outcome in dialysis patients. An increased intima media thickness (IMT) of the CCA may both represent a reaction to a haemodynamic burden as well as atherosclerosis. With a new ultrasound technique CCA-IMT and IMT-inhomogeneity, a novel parameter of spatial...

....................................................................................................................... iv INTRODUCTION ................................................................................................................ 1 CHAPTER 1 MAGNETIC RESONANCE INHOMOGENEITY CORRECTION................ 3 1.1 Magnetic Resonance Image Acquisition Process ............................

Purpose Susceptibility weighted imaging (SWI) based on GRE provides enhancement of susceptibility difference which is useful for visualization of vein, micro-hemorrhage and iron deposition. However, GRE suffers from the macroscopic B0 inhomogeneity due to air/tissue boundary and this effect is shown as SNR loss both in magnitude and phase. Previously, 3D z-shim multi-echo GRE (mGRE) pulse seque...

This study concentrates on the free pure radial vibrations of hollow spheres made of hypothetically functionally simple power rule graded materials having identical inhomogeneity indexes for both Young’s modulus and the density in an analytical manner. After offering the exact elements of the free vibration coefficient matrices for free-free, free-fixed, and fixed-fixed restraints, a parametric...

Love-type wave generation in a fiber-reinforced medium placed over an inhomogeneous orthotropic half-space is analysed. The upper and lower boundary surfaces of the fiber reinforced medium are periodically corrugated. Inhomogeneity of half-space is caused by variable density and variable shear modules. Displacement components for layer and half-space are derived by applying separable variable t...

We perform a numerical study of emergent spiral wave activity in a two-dimensional reaction-diffusion-mechanics medium with a regional inhomogeneity in active and passive mechanical properties. We find that self-sustaining spiral wave activity emerges for a wide range of mechanical parameters of the inhomogeneity via five mechanisms. We classify these mechanisms, relate them to parameters of th...

Using differential magneto-optical imaging, we address the question of mesoscopic inhomogeneity in underdoped Bi2Sr2CaCu2O8 (Bi-2212) single crystals. Among other features, it is shown that an anomalous temperature dependence of the penetration field and of the first order transition (FOT) field of the vortex lattice in such crystals can be understood as arising from inhomogeneity. The effect o...

BACKGROUND If undetected, infrarenal Abdominal Aortic Aneurysm (AAA) growth can lead to rupture, a high-mortality complication. Some AAA patients exhibit inhomogeneous luminal contrast attenuation at first-pass CT angiography (CTA). This study assesses the association between this observation and aneurysm growth. METHODS Sixty-seven consecutive pre-repair AAA CTAs were included in this retros...

The influences of body posture and tidal volume (VT) on inter- and intraregional ventilation inhomogeneity were assessed by normalized phase III slope (Sn(III)) analysis of multiple-breath washout recordings of SF(6) and He in 11 healthy men. Washouts with target VT of 750, 1,000, and 1,250 ml were performed standing and supine. A linear-fit method was used to establish the contributions of con...