MR properties of excised neural tissue following experimentally induced demyelination.
Changes in the magnetic resonance (MR) parameters of demyelinated neural tissue were measured in vitro using an experimental animal model. A tellurium (Te) diet was applied to weanling rats to induce the demyelination process in the sciatic nerve. The quantitative MR parameters, such as T(1), T(2) relaxation time constants and magnetization transfer (MT) were measured each day after applying the Te diet (up to 7 days) and were found to be substantially different from those of normal nerves. An increase in the average T(1) and T(2) was observed along with a decrease in the MT ratio (MTR) and the quantitative MT parameter M(0B), which describes the semisolid pool of protons. Most of the MR parameters correlated very well with the myelin fraction of neural tissue evaluated by quantitative histopathology. The T(2) relaxation spectrum provided the most efficient quantitative assessment of changes in neural tissue microstructure and its analysis resulted in a powerful tool to distinguish the processes of demyelination and inflammation. In comparison, the MT measurements were less successful.
Odrobina
Ewa E
EE
Imaging Research, Sunnybrook and Women's College Health Science Centre, Toronto, Ontario, Canada.
Lam
Toby Y J
TY
Pun
Teresa
T
Midha
Rajiv
R
Stanisz
Greg J
GJ
D000818:Animals; D003711:Demyelinating Diseases / Q000139:chemically induced / Q000473:pathology*; D004195:Disease Models, Animal; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D066298:In Vitro Techniques; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051381:Rats; D011917:Rats, Inbred Lew; D015203:Reproducibility of Results; D012584:Sciatic Nerve / Q000187:drug effects / Q000473:pathology*; D020426:Sciatic Neuropathy / Q000139:chemically induced / Q000473:pathology*; D012680:Sensitivity and Specificity; D013691:Tellurium
D013691:Tellurium