In vivo relaxation times of gray matter and white matter in spinal cord
Related Experiment Video
Updated: Aug 18, 2026

An Ex Vivo Laser-induced Spinal Cord Injury Model to Assess Mechanisms of Axonal Degeneration in Real-time
Published on: November 25, 2014
P Narayana1, D Fenyes, N Zacharopoulos
1Department of Radiology, University of Texas at Houston Medical School, 77030, USA. pan@msrad72.med.uth.tmc.edu
Abstract:
In vivo relaxation times and relative spin densities of gray matter (GM) and white matter (WM) of rat spinal cord were measured. Inductively coupled implanted RF coil was used to improve the signal-to-noise ratio required for making these measurements. The estimated relaxation times (in milliseconds) are: T1(GM) = 1021+/-93, T2(GM) = 64+/-3.4, T1(WM) = 1089+/-126, and T2(WM) = 79+/-6.9. The estimated relative spin densities are: rho(GM) = (60+/-2.3)% and rho(WM) = (40+/-2.1)%. The T1 values of GM and white matter are not statistically different. However, the differences in T2 values and spin densities of GM and WM are statistically significant. These in vivo measurements indicate that the observed contrast between GM and WM in spinal cord MR images mainly arises from the differences in the spin density.
Related Concept Videos
The Spinal Cord
Magnetic Resonance Imaging
Atomic Nuclei: Types of Nuclear Relaxation
In spin–lattice or longitudinal relaxation, the excited spins exchange energy with the surrounding lattice as they return to the lower energy level. Among several mechanisms that contribute to spin–lattice relaxation, magnetic dipolar interactions are significant. Here, the excited nucleus transfers energy to a nearby...
Spinal Cord: Cross-sectional Anatomy
Gray Matter and its Components
Central to the gray matter is...

