 Hi everyone, my name is Mathvi, I am third year resident in Krishna Institute of Medical Science Karat. So today I am going to present the paper on characteristics of ring enhancing lesions in brain in correlation with MRI and MR spectroscopy. Introduction, MRI heads in early diagnosis of the diseases which is visually demonstrated as by contrast between gray-white matter junction differentiation, tumor ischemia, infarction, edema, multiple sclerosis, plaque, infection, abscess and hemorrhage. But in few cases lesions are seen in the subcortical area and deep layers of brain parenchyma. Magnetic resonance spectroscopy is a vital tool for identifying and diagnosing infective etiologies like intracranial abscess and non-infectious lesions like primary intraparenchymal neoplasms, demyelination, lymphoma and cerebral metastasis. The possible nature and characteristics of these lesions can be achieved by MR spectroscopy. On a routine MRI scan by analyzing the quantity and ratio of tissue metabolites such as lipid, colon, amino acids, n-acetyl, aspartate, etc. Launched student studies have demonstrated that proton MR spectroscopy is useful in monitoring the progression of disease and in response to the treatment. MR spectroscopy also has a vast prognostic implication. So there is a mnemonic for ring enhancing lesions, it is magical DR. M stands for metastasis, A stands for abscess, G stands for granuloma and glioblastoma, I stands for infarct seeds, N stands for condition, A stands for aids which includes toxoplasmosis, L stands for lymphoma, D stands for demyelination, R stands for radiation necrosis or resolving hematoma. Ames and objectives of my study to analyze and identify the various characteristic ranges of these ring enhancing lesions in brain on conventional MRI and proton MR spectroscopy which leads to an early diagnosis, treatment, response assessment and minimize the complications in such patients. The materials and methods of my study, retrospective cross-sectional evaluation of MRF features in 70 patients with ring enhancing lesions in department of radio diagnosis, Kim Scarad. MR brain was done for patients on Siemens 1.5 Tesla with contrast and other specific sequences as and when seemed appropriate. 70 cases of ring enhancing lesions are where followed and segregated according to MR findings in the tuberculoma, neurocystis, circuses, metastasis, cerebral lapses, primary brain neoplasm, toxoplasmosis, radiation across and demyelination disorders. So moving on to my case, 65-year-old male patient with past history of tuberculosis presented with multiple episodes of seizure since one week. MR brain was performed, T2 axial, flare axial, diffusion weighted images and contrast images showing multiple discrete and conglomerated nodular and ring enhancing altered signal intensity lesions noted involving left parietal lobe which is appearing T2 and flare hyper intense with a significant perillational edema showing no diffusion restriction. On MR spectroscopy, there is a lipid lactate peak. Based on MR, MR spectroscopy and CSF cytology suggestive of tuberculoma. Moving on to next case, 30-year-old male presented with multiple episodes of seizure since one day, MR brain was performed, T1 axial, T2 axial, flare axial, diffusion weighted images, HEMO and post-contrast axial images showing multiple well-defined round lesions diffusely in bilateral cerebral hemispheres involving frendle, ganglio-capsular region, midbrain, parietal and occipital lobes which is appearing hypo-indense on T1 with eccentric hyper-indensity which represents cortex and showing hyper-indensities in T2 and flare with few of the lesions showing perillational edema showing no diffusion restriction and blooming on HEMO sequences. On post-contrast images, there is few of the lesions are showing ring enhancement while few of the lesions are not showing any contrast enhancement which we can appreciate in T2 but that lesions are not showing contrast enhancement. And the lesions which are showing edema and contrast enhancement is likely to represent granular nodular stage evolving to calcific nodular stage while the other which with no enhancement are likely to represent neurocystisercosis in calcified nodular stage. MR spectroscopy was performed from the same patient and shows a succinate peak at 2.4 ppm. Moving on to next case, 55-year-old male patient known case of CEL lung presented with gidiness and one episode of seizure, MR brain was performed T1 axial, T2 axial, flare axial, diffusion weighted images, HEMO sequence and post-contrast axial images showing well defined altered signal intensity noted in right front lobe appearing heterogeneously hyper-indense on T2 and flare and showing hypo-indense on T1 with peripheral T1 hyper-indense room which is appearing T1 hypo-indense showing heterogeneous patchy diffusion restriction and no blooming on HEMO sequences. On post-contrast images we can see there is a ring enhancing, ring enhancement noted. On MR spectroscopy there is a lipid lactate peak and increased colon peak which has a suggestive of metastasis. Moving on to next case, 16-year-old female with history of fever, vomiting and persistent headaches since 15 days, total leukocyte count were raised, MR brain was performed, T1, T2, flare, diffusion weighted images and post-contrast T1 axial images showing multiple well defined involved multilobulated and few conglomerated lesions showing relatively smooth and convex inner margins appearing iso-indense to hypo-indense with hyper-indense rim and appearing hyper-indense sender and hypo-indense rim on T2 and there is partial suppression on flare and showing evid diffusion restriction and post-contrast enhancement. So on T2 weighted images there is two concentric rims that is outer hypo-indense rim and inner hyper-indense rim. So this is there is a sign known as dual rim sign which we can appreciate over here. On MR spectroscopy there are low NA levels, there is high valine-loosin-iso-loosin peak at 0.9 ppm and an alanine peak at 1.48 ppm. So features are suggestive of cerebral absence. Moving on to next case, 63-year-old male patient presented with complaints of headaches in two months, MR brain was performed, T1 axial, T2 axial, flare axial, diffusion weighted images, chemo sequences and post-contrast T1 axial images showing a large well-defined altered signal intensity solid lesion noted in gesta ventricular region of left paretoxuptile temporal group involving the spleenium of the corpus callosum, minimal flare hyper-indensity noted and there is effacement of edges and cortical sulcal spaces, silvian fissure and mass effect on the ipsilateral lateral ventricle and causing midline shift to right side. It is appearing iso-indense on T1 weighted hyper-indense signal on T2 weighted or flare sequences and showing diffusion weighted image and ADC sequences, patchy areas of blooming on hemosequence and post-contrast enhancement. Non-enhancing T2 hyper-indense areas are noted within the lesions suggestive of cystic or necrotic areas, few of them showing blood fluid levels which we can see there is blooming on hemosequences. Patient has undergone excisional biopsy and turned out to be glioblastoma, IDH wild type. MR spectroscopy was done for the same patient and the marked elevation of colon levels, creatin and the myo-inacetyl levels and which is suggestive of glioma, but there is lipid lactate peak also in our case so it is suggestive of high-grade glioma. Moving on to next case, 60-year-old female patient, own case of HIV presented with dendritic and fever since one week, MR brain was performed, T1 axial, T2 axial, flare axial, diffusion weighted images and post-contrast T1 axial images showing well-defined, lobulated, altered signal-indensity lesion noted in right lateral frontal parietal lobe and in splenium of the corpus callosum. Minimal perillational edema is noted and the lesions are appearing iso-indense on T1, hyper-indense on T2 and flare and showing diffusion restriction, patchy diffusion restriction and contrast enhancement. On MR spectroscopy, there is colon peak reduced NA level and also lipid lactate peak can be appreciated so features are suggestive of CNS lymphoma. Next case, 28-year-old male patient, known case of HIV presented with negativity and fever since one week, MR brain, T1 axial, T2 axial, flare, diffusion weighted images, T1 and flare post-contrast images showing multifocal concentric target sign with concentric alternating hyper and hypo-indensities noted involving bilateral basal ganglia appearing hypo-indense on T1, hyper-indense on T2 and flare showing minimal peripheral diffusion restriction and post-contrast enhancement. On MR spectroscopy, there is lipid lactate peak while the colon levels are absent. So, CSF cytology was done and came out to be toxoplasmosis. Moving on to next case, 35-year-old female presenter with generalized weakness and left her battle pain since one month, MR brain was performed, T2 axial, flare axial, diffusion weighted images, T2 saggy images and contrast T1 axial images and coronal images showing multiple T2 flare hyper-indensities in bilateral white matter region predominantly in the perivendricular region. Along the perimedular veins, calloceptal interface, then subcortical u-fibers and the cervical medullary junction appearing T2 and flare hyper-indense and showing no diffusion restriction and mild incomplete ring enhancement seen in this plenium of the corpus callosa. And also, there is an ill-defined mild enhancement of left optic nerve after contrast administration. CSF cytology was done and was positive for IgG called oligoclonal blend, suggestive of multiple sclerosis. MR spectroscopy was done and is marked elevation of lipid peak at 1.33 ppm and mild glutamine glutamate peak at 2.2 ppm. Moving on to next case, 60-year-old female follow-up case of low grade astrocytoma post-radio therapy with complaints of headache. MR brain was performed, T1 axial, T2 axial, flare axial, diffusion weighted images and post-contrast coronal images showing an irregular area faulted signal intensity noted in left frontal lobe appearing hyper-indense on T1 and flare and hyper-indense on T2 showing no diffusion restriction and mild contrast enhancement. And there is a gliosis in the left frontal lobe with a craniotomy defect which is suggestive post-operative changes. And on MR spectroscopy, we can appreciate there is lipid lactate peak and reduced NAA levels based on MR spectroscopy and interval follow-up features favor radiation across this over recurrence or residual lesion. So results of my study is tabulated over here. So there were 20 cases of tuberculoma, 15 cases of Neurocyste circumstances, 13 cases of cerebral lapses, 9 cases of metastasis, 7 cases of primary brain neoplasm, 4 cases of toxoplasmosis and 2 cases of others which includes de-hemylation and radiation necrosis. So enhancement characteristics, thick and nodular lesion is neoplastic, thick and regular lesion could be abscess, thin and regular with granated margins could be fungal abscess, incomplete ring towards cortex or gray matter, includes de-hemylation, ring enhancement with neural nodule includes pylocytic astrocytoma. There are specific MR spectroscopy characteristics, one is colon, lactate and succinate peaks in Neurocyste circumstances, lipid lactate peak which is seen in tuberculoma, radiation necrosis, toxoplasmosis, amino acids like valine, isolusine, lucinyl anion peak which is seen in abscess, peritumoral colon peak, myoenocytol and creatin peak in intra-tumoral region is primary brain tumors, lipid lactate and colon peak is seen in metastasis, colon and lipid peak twin peak sign which is seen in lymphoma and glutamine glutamate peak which is seen in white matter disorders. Conclusion, use of MRA along with MR spectroscopy is a very useful, important and primary research tool in neurodiagnosis, most common ring enhancing lesions experienced in developing countries like India's tuberculomas and NCC, T2 weighted hyperendensity with no diffusion restriction and presence of scolics helps in differentiating NCC from tuberculomas. Tuberculomas show lipid lactate peak whereas NCC shows succinate peak, abscess shows T2 weighted hypoindense rim with central diffusion restriction that is dual rim sign with amino acid peaks, hygrigliomas may be lobulated with central necrotic component with thick irregular ring enhancing lesions with very high colon creatin ratios, myoenocytol peak and low NA whereas metastasis are well defined T2 weighted hyperendense lesions with high colon and lipid lactate peaks. Tumifactivity in myelination most commonly shows incomplete ring enhancement with open part predominantly towards the cortex and glutamine glutamate peak. Toxoplasma appear T2 flare concentric ring pattern with lipid lactate peak whereas lymphoma shows twin peak sign that is high colon and lipid peak. Radiation across the show lipid lactate peak whereas recurrent mass lesions show high colon peak and lipid lactate peak. Hence conventional MR imaging along with MR spectroscopy can be useful to reach a correct diagnosis and also in differentiation of perillational edema from neoplastic invasion. So these are my references. Thank you.