Objective

    To study the value of long echo time (TE) point resolved spectroscopy (PRESS) and stimulated echo acquisition mode (STEAM) of

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H-magnetic resonance in detection of multiple scleroses (MS) in brain white matter with a normal appearance.     Methods    Conventional magnetic resonance imaging was performed in 56 patients with relapsing-remitting MS (RRMS) and in 25 healthy volunteers. The results were analyzed using the long TE PRESS sequence and short TE STEAM sequence of

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H- magnetic resonance. Concentrations of metabolic products

including N-acetylaspartic acid (NAA)

choline (Cho)

creatine (Cr)

lipid (Lip)

lactic acid (Lac)

and inositol (Ins)

were measured in each region of interest (ROI). Changes of NAA/Cr

Cho/Cr

Lip+Lac/Cr and Ins/Cr in MS and brain white matter with a normal appearance were analyzed.     Results    Long TE PRESS sequence showed that the NAA/Cr

Cho/Cr and NAA/Cho were significantly different in white matter with acute and chronic lesions or in white matter with a normal appearance (P0.01). No significant difference in NAA/Cr and NAA/Cho was observed in white matter with acute and chronic lesions (P0.05). Short TE STEAM sequence showed that the NAA/Cr

Cho/Cr and Lac+Lip/Cr were significantly different in white matter with acute lesions or with a normal appearance. Long TE PRESS sequence and short TE STEAM sequence had no significant difference in detecting NAA/Cr and Cho/Cr in MS (P0.05).However

short TE STEAM sequence was advantageous over long TE PRESS sequence in detecting the Lip

Lac and Ins peaks.     Conclusion    Both long TE PRESS and short TE STEAM sequence can detect abnormal metabolites in MS and in white matter with a normal appearance. However

STEAM can detect more metabolites than long TE PRESS.