Mandeep Kang MD, Abstract Co-Author: Nothing to Disclose

Niranjan Khandelwal MD, Abstract Co-Author: Nothing to Disclose

Supriyo Ghatak MS, Abstract Co-Author: Nothing to Disclose

Ashis Pathak MS, Abstract Co-Author: Nothing to Disclose

Sudha Suri, Abstract Co-Author: Nothing to Disclose

Kushaljit Singh Sodhi MD, Presenter: Nothing to Disclose

To detect Diffuse Axonal Injury (DAI) using MRS in head injury (HI) patients with normal CT scans and to determine correlation between MRS findings in DAI and Glasgow Coma Scale (GCS) of pts.

Study group: 15 pts of HI with normal CT scans at admission underwent MR & MRS once clinically stable. Control group: 5 pts (age matched) with normal MR scan for clinical indications other than HI. Pts with prior HI, systemic illnesses or coagulopathy were excluded.Routine conventional MR sequences were performed. Proton spectra were acquired from both basifrontal lobes, splenium & pons. HASTE images in 3 orthogonal planes were used for localization of voxels in ROI. MRS was performed using PRESS with CHESS for water suppression. The spectral peaks for N- acetyl aspartate (NAA), Choline (Cho) & Creatine (Cr) were identified & NAA/Cr, NAA/Cho & Cho/Cr were calculated.Mann-Whitney U test was used to compare control & study groups as a whole & after dividing into mild, moderate & severe HI groups. The Spearman Ranks test was used to correlate the GCS with the metabolite ratios.

The mean delay between HI & MRS was 4.33d (1-13d). Severity of HI assessed using GCS ranged between 4-13. 1 pt fell in mild, 2 in moderate & 12 pts in severe HI groups.On MR, 9 pts showed multiple areas of signal abnormalities in the white matter, of these 4 pts had abnormal signal in the splenium. 1 pt had a hemorrhagic contusion in the splenium & 1 pt had features suggestive of DAI. MR of 4 pts was normal.In splenium, the NAA value, NAA/Cr & NAA/Cho ratios were significantly reduced in the HI pts compared to controls, but the Cho/Cr ratio did not show any statistical difference. In both basifrontal lobes & pons, the metabolite values & their ratios did not differ significantly in the two groups.The decrease in NAA/Cr & NAA/ Cho ratios in the splenium were highly significant in severe HI pts ( p=0.003 & p=0.008), however the ratios were not significantly different in cases of mild & moderate HI.There was no correlation seen between MRS & GCS.

MRS provides a useful method for evaluating pts with traumatic HI for DAI. It holds promise for depicting the underlying alteration at molecular level.

Kang, M, Khandelwal, N, Ghatak, S, Pathak, A, Suri, S, Sodhi, K, The Role of Magnetic Resonance Spectroscopy in Diagnosis of Diffuse Axonal Injury in Patients of Head Injury.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4411344.html