AbstractIntroduction: Ring-enhancing lesions is the most common abnormality faced in neuro-imaging. Imaging modalities commonly used to diagnose such lesions are Computed Tomography (CT) and MRI. However, these lesions are considered challenging for the radiologists. Diagnosing ring enhancing lesions by conventional MRI is challenging, especially when neoplastic, non-neoplastic lesions and infections are to be differentiated. Differentiation between tuberculoma and neurocysticercosis is still a problem for radiologist as both look similar on conventional MRI. Magnetic resonance spectroscopy (MRS) may able to clearly differentiate them based on metabolite level. Present study was conducted to study characteristics of various ring enhancing lesions of brain using conventional MRI and magnetic resonance spectroscopy (MRS) to differentiate neoplastic, infections, inflammatory and vascular lesions
Materials and Methods: 50 patients between age 10 to 70 years diagnosed with ring enhancing lesions of brain based on MR studies fulfilling inclusion and exclusion criteria were enrolled. MRI scan was performed using the MRI GE optima 360-16 channel in all. Single voxel magnetic resonance spectroscopy (MRS) used instead of multi-voxel which was placed on the lesion in a way that the maximum area of the lesion, its margin and the normal brain tissue will be covered.
Observations and Results: Primary Brain Tumors found in 16 (32%) cases, Metastasis in 22 (44%), Abscess in 8 (16%), Neurocysticercosis (NCC) in 2 (4%), Tuberculoma in 1 (2%) & Tumefactive Demyelination in 1 (2%) case. In majority of cases i.e. 38 (76%) size of the lesion was <2 cm. In about 26 (52%) cases number of lesions were 2 to 4 in number. Restriction on diffusion was found in 29 (58%) cases. In majority choline 26 (52%) & lipid 24 (48%) was the metabolite peak found
Conclusion: Magnetic Resonance Spectroscopy (MRS) was found a useful tool in the diagnosis of ring enhancing lesions especially in case of delineating lesions with similar presentations such as tuberculoma and neurocysticercosis.
