Wave propagation in disordered (random) media is the underlying theme. Many types of wave propagation problems can most conveniently be analyzed in this framework. Acoustic waves in the earth's crust and shallow water (or surface gravity) waves are two examples. The interaction of sound waves with the heterogeneities in the earth's crust is important in seismology. The interaction of surface gr...

OBJECTIVE To assess the feasibility and reliability of apparent diffusion coefficient (ADC) measurements of normal adrenal glands. MATERIALS AND METHODS This was a retrospective study involving 32 healthy subjects, divided into two groups: prepubertal (PreP, n = 12), aged from 2 months to 12.5 years (4 males; 8 females); and postpubertal (PostP, n = 20), aged from 11.9 to 61 years (5 males; 1...

This issue of Journal of Medical Radiation Sciences includes a study (Rundle-Thiele et al.) that investigates the correlation between magnetic resonance imaging (MRI)-based estimates of water mobility in glioblastoma tumours and expression of the prognostically important gene promoter methylguanine methyltransferase (MGMT). The authors address previous inconsistent reports regarding a correlati...

Apparent diffusion coefficient (ADC) measurement in diffusion-weighted imaging (DWI) has been reported to be a helpful biomarker for detection and characterization of lesion. In view of the importance of ADC measurement reproducibility, the aim of this study was to probe the variability of the healthy hepatic ADC values measured at 3 MR scanners from different vendors and with different field s...

This work describes the basics of diffusion measurement in biological systems. The first portion is dedicated to providing an understandable, classical-mechanical description of the Stejskal ] Tanner pulse sequence to give the reader an intuitive understanding of the measurement. This is followed by a description of the various aspects of water motion in biological systems that should be taken ...

The apparent diffusion coefficients (ADCs) of a series of markers concentrated in the extracellular space of normal rat brain were measured to evaluate, by inference, the ADC of water in the extracellular space. The markers (mannitol, phenylphosphonate, and polyethylene glycols) are defined as "compartment selective" because tissue culture experiments demonstrate some leakage into the intracell...

BACKGROUND AND PURPOSE The aim of this study was to measure apparent diffusion coefficients in rat brain tissue exposed to ouabain, glutamate, and N-methyl-D-aspartate and to compare them with apparent diffusion coefficients found in acute cerebral ischemia. METHODS The apparent diffusion coefficient was measured using magnetic resonance microscopy in four groups of Sprague-Dawley rats after ...