Estimation of the macromolecular proton fraction and bound pool T2 in multiple sclerosis

• Published in: Multiple sclerosis Vol. 10; no. 6; pp. 607 - 613
• Main Authors: GR, Davies, DJ, Tozer, M, Cercignani, A, Ramani, CM, Dalton, AJ, Thompson, GJ, Barker, PS, Tofts, DH, Miller
• Format: Journal Article
• Language: English
• Published: Thousand Oaks, CA Sage Publications 01.12.2004; Arnold; Sage Publications Ltd
• Subjects: Adult; Age Factors; Aged; Biological and medical sciences; Brain - pathology; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; Female; Humans; Immunomodulators; Magnetic Resonance Imaging - methods; Magnetic Resonance Imaging - standards; Male; Medical sciences; Middle Aged; Multiple Sclerosis, Chronic Progressive - pathology; Multiple Sclerosis, Relapsing-Remitting - pathology; Neurology; Pharmacology. Drug treatments; Protons; Reproducibility of Results; Sex Factors; myelin; normal appearing white matter; magnetization transfer ratio; lesions; multiple sclerosis; gray matter; Human; Multiple sclerosis; Nervous system diseases; Myelin; Estimation; Spin echo; White matter; Relaxation time; Inflammatory disease; Contour; Central nervous system disease; Proton; Degenerative disease; Models
• ISSN: 1352-4585; 1477-0970
• DOI: 10.1191/1352458504ms1105oa

This study used a model for magnetization transfer (MT) to estimate two underlying parameters: the macromolecular proton fraction (f) and the bound pool T2 (T2b) in patients with multiple sclerosis (MS). Sixty patients with clinically definite MS and 27 healthy controls were imaged using: (1) a dual echo fast spin echo sequence, (2) a MT sequence (with ten MT power and offset frequency combinations) and (3) proton density and T1 weighted sequences (for T1 relaxation time estimation). Fourteen normal-appearing white matter (NAWM) regions of interest (ROI) and six normal-appearing gray matter (NAGM) ROIs were outlined in all subjects. Lesions were also contoured in subjects affected by MS. The model was fitted to the data leading to estimates of T2b and f. Results showed that T2b was increased in lesions whereas f was reduced. In NAWM, f was decreased while T2b was only increased in secondary progressive MS. NAWM f correlated modestly with disability. Further studies are needed to investigate the pathological basis of the abnormalities observed.