Test-retest repeatability of ADC in prostate using the multi b-Value VERDICT acquisition.

Purpose: VERDICT (Vascular, Extracellular, Restricted Diffusion for Cytometry in Tumours) MRI is a multi b-value, variable diffusion time DWI sequence that allows generation of ADC maps from different b-value and diffusion time combinations. The aim was to assess precision of prostate ADC measurements from varying b-value combinations using VERDICT and determine which protocol provides the most repeatable ADC.

Materials And Methods: Forty-one men (median age: 67.

An alternative approach to contrast-enhanced imaging: diffusion-weighted imaging and T-weighted imaging identifies and quantifies necrosis in Wilms tumour.

Objectives: Volume of necrosis in Wilms tumour is informative of chemotherapy response. Contrast-enhanced T-weighted MRI (Tw) provides a measure of necrosis using gadolinium. This study aimed to develop a non-invasive method of identifying non-enhancing (necrotic) tissue in Wilms tumour.

Stroke onset time estimation from multispectral quantitative magnetic resonance imaging in a rat model of focal permanent cerebral ischemia.

Background: Quantitative T2 relaxation magnetic resonance imaging allows estimation of stroke onset time.

Aims: We aimed to examine the accuracy of quantitative T1 and quantitative T2 relaxation times alone and in combination to provide estimates of stroke onset time in a rat model of permanent focal cerebral ischemia and map the spatial distribution of elevated quantitative T1 and quantitative T2 to assess tissue status.

Methods: Permanent middle cerebral artery occlusion was induced in Wistar rats.

A spatiotemporal theory for MRI T2 relaxation time and apparent diffusion coefficient in the brain during acute ischaemia: Application and validation in a rat acute stroke model.

The objective of this study is to present a mathematical model which can describe the spatiotemporal progression of cerebral ischaemia and predict magnetic resonance observables including the apparent diffusion coefficient (ADC) of water and transverse relaxation time T2 This is motivated by the sensitivity of the ADC to the location of cerebral ischaemia and T2 to its time-course, and that it has thus far proven challenging to relate observations of changes in these MR parameters to stroke timing, which is of considerable importance in making treatment choices in clinics. Our mathematical model, called the cytotoxic oedema/dissociation (CED) model, is based on the transit of water from the extra- to the intra-cellular environment (cytotoxic oedema) and concomitant degradation of supramacromolecular and macromolecular structures (such as microtubules and the cytoskeleton). It explains experimental observations of ADC and T2, as well as identifying the rate of spread of effects of ischaemia through a tissue as a dominant system parameter.

Timing the ischaemic stroke by 1H-MRI: improved accuracy using absolute relaxation times over signal intensities.

One in four ischaemic stroke patients are ineligible for thrombolytic treatment due to unknown onset time. Quantification of absolute MR relaxation times and signal intensities are potential methods for estimating stroke duration. We compared the accuracy of these approaches and determined whether changes in relaxation times and signal intensities identify the same ischaemic tissue as diffusion MRI.