NMR imaging of the brain using spin-echo sequences

T 2 : The Transverse Relaxation Time

“…It is now generally accepted that MRI is more sensitive than CT in the detection of cerebral lesions Bailes et al, 1982;McLachlan et al, 1985;Latack et al, 1986;Lesser et al, 1986;Kuzniecky et al, 1987) and of the conventional MRI sequences, T 2 -weighted imaging is the most discriminating (Smith et al, 1985). Early studies proposed that the evaluation of a combination of NMR parameters, principally proton density, T 1 -and T 2 -relaxation times, may provide not only sensitivity, but tissue specificity, allowing the complete and accurate characterization of pathological tissue in vivo (Damadian, 1971).…”

In vivo magnetic resonance methods in pharmaceutical research: current status and perspectives

“…The prolongation of the transverse relaxation time T 2 associated with the formation of a vasogenic edema provided excellent contrast for discrimination of infarcted versus healthy brain tissue. 7,8 MRI was soon applied to study the early pathological events associated with cerebral infarction in animal models such as unilateral occlusion of the common carotid artery in gerbils 9 or the middle cerebral artery occlusion (MCA-O) in cats. 10 Both models were of limited use for drug development due to large variability in the former species and complexity of the preparation in the latter, preventing comparative drug studies on a large scale.…”

Brain Tumors in Man and Animals: Report of a Workshop

“…The male/female ratio of 0.6 simula-ted the human situation. The site was intracranial (88), intraspinal (15) and intraorbital (3). The intracranial meningiomas in the dog, while histologically similar to man, manifested some significant variations.…”