An advanced magnetic resonance imaging perspective on the etiology of deep tissue injury.

Early diagnosis of deep tissue injury remains problematic due to the complicated and multifactorial nature of damage induction and the many processes involved in damage development and recovery. In this paper, we present a comprehensive assessment of deep tissue injury development and remodeling in a rat model by multiparametric magnetic resonance imaging (MRI) and histopathology. The tibialis anterior muscle of rats was subjected to mechanical deformation for 2 h.

A MRI-Compatible Combined Mechanical Loading and MR Elastography Setup to Study Deformation-Induced Skeletal Muscle Damage in Rats.

Deformation of skeletal muscle in the proximity of bony structures may lead to deep tissue injury category of pressure ulcers. Changes in mechanical properties have been proposed as a risk factor in the development of deep tissue injury and may be useful as a diagnostic tool for early detection. MRE allows for the estimation of mechanical properties of soft tissue through analysis of shear wave data.

Assessment of Myocardial Fibrosis in Mice Using a T2*-Weighted 3D Radial Magnetic Resonance Imaging Sequence.

Background: Myocardial fibrosis is a common hallmark of many diseases of the heart. Late gadolinium enhanced MRI is a powerful tool to image replacement fibrosis after myocardial infarction (MI). Interstitial fibrosis can be assessed indirectly from an extracellular volume fraction measurement using contrast-enhanced T1 mapping.

Quantitative first-pass perfusion MRI of the mouse myocardium.

In this article, we present a first-pass perfusion imaging protocol to determine quantitative regional perfusion values (in mL min(-1) g(-1)) of the mouse myocardium. Perfusion was quantified using a Fermi-constrained deconvolution of the myocardial tissue response with the arterial input function. A dual-bolus approach was implemented.

Intersubject differences in the effect of acidosis on phosphocreatine recovery kinetics in muscle after exercise are due to differences in proton efflux rates.

(31)P magnetic resonance spectroscopy provides the possibility of obtaining bioenergetic data during skeletal muscle exercise and recovery. The time constant of phosphocreatine (PCr) recovery (tau(PCr)) has been used as a measure of mitochondrial function. However, cytosolic pH has a strong influence on the kinetics of PCr recovery, and it has been suggested that tau(PCr) should be normalized for end-exercise pH.

Comparison between prospective and retrospective triggering for mouse cardiac MRI.

High-resolution magnetic resonance imaging (MRI) has evolved into one of the major non-invasive tools to study the healthy and diseased mouse heart. This study presents a Cartesian CINE MRI protocol based on a fast low-angle shot sequence with a navigator echo to generate cardiac triggering and respiratory gating signals retrospectively, making the use of ECG leads and respiratory motion sensors obsolete. MRI of the in vivo mouse heart using this sequence resulted in CINE images with no detectable cardiac and respiratory motion artefacts.