PROTON MRS OF GADOLINIUM-ENHANCING MS PLAQUES AND METABOLIC CHANGES IN NORMAL-APPEARING WHITE-MATTER

Localized short echo time (TE = 20 ms), stimulated echo acquisition mo de, and double spin echo (TE = 135 ms) proton spectroscopy were perfor med in clearly defined, acute Gadolinium (Gd)-enhancing multiple scler osis (MS) plaques of 22 patients with clinically definite MS, The reso nances of N-acetylated metabolites (NA), creatine/phosphocreatine (Gr) , choline-containing compounds (Cho), glycine/myo-inositol (Ino), and lactate were evaluated, The ratios of NA/Cr and NA/Cho were significan tly decreased, Cho/Cr increased, and Ino/Cr remained unchanged. No mar ker peaks or elevated lactate levels were found, The measured metaboli c changes were practically independent of the relative plaque size wit hin the volume of interest (8 ml). Thus, the spectral changes measured with H-1 MRS in acute Gd-enhancing MS plaques originate not only from the lesion as depicted by MRI, but also from the surrounding normal-a ppearing white matter.