Maria Otaduy, Presenter: Nothing to Disclose

Thiago Junqueira, Abstract Co-Author: Nothing to Disclose

Dagoberto Callegaro, Abstract Co-Author: Nothing to Disclose

Claudia Da Costa Leite, Abstract Co-Author: Nothing to Disclose

The purpose of this study is to determine whether proton magnetic ressonance spectroscopy (1H-MRS) can detect metabolic alterations in the hippocampus of MS patients in the early stage of disease.

Nineteen relapsing remitting MS patients (14 female) and 15 healthy controls (11 female), with mean age 30.6 and 31.4y respectively, were examined with a 3.0T magnet (Intera Achieva, Philips Healthcare, The Netherlands) using an eight channel head coil. Mean disease duration was only 32 months and mean EDSS = 1.3. No patients presented history of depression. MRI acquisition included conventional structural images and a SS-T2-weighted axial image along the hippocampus for localization purposes of the MRS voxel. Single-voxel 1H-MRS was performed using the PRESS sequence with a NS=128, a TR of 1500ms and with two different TE= 35 and 135 ms. Voxel localization was planned on an oblique axial T2-weighted image along the hippocampus. Voxel size was fixed for all patients and controls to be: 10mm in the I-S, 15 mm in the R-L, and 40 mm in the A-P direction, resulting in a total voxel size of 6 cm3. It was observed the correct position of this voxel also on coronal images of the hippocampus. We used two REST slabs (one coronal and one axial), in order to avoid lipid contamination with surrounding fat. 1H-MRS data were processed with LCModel software and metabolite concentrations were scaled to the water tissue content. NAA, Cr, Cho, mI, Glx and Glu were quantified. Patient results were compared to control values by using a Student t-test and a p value up to 0.05 was considered statistically significant.

For a TE=35 ms we found in patients a statistically significant decrease for the Glu/Cr when compared to controls (p=0.034). There was also a tendency of lower mI, Glu and Glx/Cr levels, but it did not reach statistically significance (p=0.066, p=0.086 and p=0.069 respectively). For a TE=135 ms we found lower NAA and NAA/Cr values (p=0.001 and 0.021 respectively).

1H-MRS reveals hippocampus metabolic alterations even in the early stage of disease.

1H-MRS can be a potential tool to monitor and quantify disease progression in the early stagesof MS. Hippocampus metabolic information can help to understand memory impairment in MS.

Otaduy, M, Junqueira, T, Callegaro, D, Leite, C, 1H-MRS Detects Metabolic Alterations in the Hippocampus of MS Patients Early in Disease.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8016251.html