title: A viable isolated tissue system: a tool for detailed MR measurements and controlled perturbation in physiologically stable tissue.
abstract: In vivo magnetic resonance imaging (MRI) assessment of neuronal tissue is prone to artifacts such as movement, pulsatile flow, and tissue susceptibility. Furthermore, stable in vivo scans of over 3 h are difficult to achieve, experimental design is therefore limited. Using isolated tissue maintained in a viable physiological state can mitigate many of these in vivo issues. This work describes the fabrication and validation of an MRI compatible viable isolated tissue maintenance chamber. Parameters measured from maintained rat optic nerves did not change significantly over 10 h: (i) mean axon radius [electron microscopy--0 h: 0.75±0.46; 5 h: 0.74±0.35; 10 h: 0.76±0.35 μm (P>>0.05, t-test], (ii) action potentials [grease-gap electrophysiology--4.89±0.16 mv, (P>>0.05, Pearson test], and (iii) diffusion tensor imaging parameters [fractional anisotropy: 0.86±0.02 (P>>0.05, Pearson test), mean diffusivity: 1.48E-06±9.74E-08 cm2/s, (P>>0.05, Pearson test)]. In addition, a thorough diffusion-weighted MR protocol demonstrated the comparable stability of viable isolated and chemically fixed rat optic nerve. This MRI compatible viable isolated tissue system allows researchers to probe neuronal physiology in a controlled environment by limiting in vivo artifacts and allowing extended MRI acquisitions.
authors: Division of Medicine and Institute of Child Health, UCL Centre for Advanced Biomedical Imaging, Department of Computer Science, University College London, London, United Kingdom. simon.richardson.09@ucl.ac.uk
authors: S
authors: S
authors: Richardson
authors: B
authors: B
authors: Siow
authors: A M
authors: AM
authors: Batchelor
authors: M F
authors: MF
authors: Lythgoe
authors: D C
authors: DC
authors: Alexander
mesh_terms: D000818:Animals; D004780:Environment, Controlled; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D009900:Optic Nerve / Q000033:anatomy & histology*; D009924:Organ Culture Techniques / Q000295:instrumentation*; D010477:Perfusion / Q000295:instrumentation*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012212:Rheology / Q000295:instrumentation*; D012680:Sensitivity and Specificity