Anastas Doreski

Abstract: Learning Objectives: The role of MR spectroscopy in differentiating Balo concentric sclerosis (BCS) from neoplastic processes (NP). Background: Balo concentric sclerosis is a rare demyelinating disease that can be hardly distinguished from neoplastic disease by noninvasive methods. The pathology underlying the concentric sclerosis is a combination of myelinated and demyelinated white mater but the pathophysiology is still being researched. It is thought that BCS is a variant of multiple sclerosis. BSC and NP can not be clinically distinguished and in some cases (ex. rapidly progressive forms of BCS) differentiating by imaging alone can represent radiological challenge. Nevertheless, both pathologies have different biochemistries so they should be differentiated by MR spectroscopy. Imaging Findings or Procedure Details: 9 patients with 1-5 nodular parenchymal mass lesions were studied. The standard MR sequences (T1 tse, T2 tse, FLAIR, diffusion imaging (DWI) and susceptibility weighted imaging (SWI)) of the brain were preformed on a 1.5 T Siemens Magnetom Essenza. Then, multivoxel MR spectroscopy 2D CSI (chemical shift imaging) TR 1500 TE 135 was performed on the lesion centre, periphery and the contralateral normal tissue. Ch/Cr, NAA/Cr ratios and also lactates and lipids were taken into consideration. Conclusions: The NAA/Cr ratio was the only marker that could distinguish between BCS and NP. In both pathologies the NAA was lower than normal, but in NP it was 3-4 times lower than in BCS lesions.Elevated Ch/Cr ratio and finding of lipids and lactates had similar values in both pathologies.