Proton Magnetic Resonance Spectroscopy of Intracranial Lesions: Assessment of differences between Tumours and Tumour like Lesions and Its applicability in Brain Lesion Characterization

Chidambaranathan, N (2011) Proton Magnetic Resonance Spectroscopy of Intracranial Lesions: Assessment of differences between Tumours and Tumour like Lesions and Its applicability in Brain Lesion Characterization. Doctoral thesis, The Tamilnadu Dr. M.G.R. Medical University, Chennai.


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Intracranial lesions are a significant health problem and present several imaging challenges. The role of imaging is no longer limited to merely providing anatomic details of the exact location of the pathology. Advanced Magnetic Resonance Imaging (MRI) techniques allow insight into the chemical makeup of certain compounds within these pathologic lesions. In vivo Proton MR Spectroscopy (1H MRS), a non-invasive technique which provides metabolic information can complement the anatomical changes found in radiological examinations of various intracranial lesions increasing diagnostic specificity. The present investigation was carried out a) To determine if there are specific MRS findings which could help differentiate between neoplastic and non –neoplastic lesions and also to identify the presence or absence of MRS features which could help differentiate one neoplasm from another. b)to determine if MRS findings could help grade gliomas pre operatively. c) To determine if MRS findings could help differentiate irradiated residual/recurrent tumours from radiation necrosis. d) To determine if MRS findings could help differentiate necrotic tumours from infective lesions such as abscesses. CONCLUSION: MR Spectroscopy in addition to appropriate conventional MRI sequences provides useful supplementary information and has a potential to validate treatment strategies. This could influence decision making with respect to prognosis and therapy in patients with intracranial lesions. Current Neuro - Imaging techniques enable use of multiple modalities to enhance the accuracy of non-invasive diagnosis. This study emphasizes the utility and validity of a simple add on technique of MRS over MRI to provide additional information in establishing the possible aetiological diagnosis of intracranial lesions. This study helps radiologists to improve diagnostic accuracy of MRI using the additional modality of MRS. MRS could help in clinical decision making in difficult cases distinguishing neoplastic from non-neoplastic lesions. During the last few years there has been an exponential growth in MRS. The phenomenal advances in neuroimaging of the brain are resulting in a paradigm change in the clinician’s approach to diagnosing and managing intracranial conditions. Advances in the ultra precise delineation of anatomical changes in the brain have resulted in increasing precision in separating normal from abnormal brain tissue. However this has not kept pace with identifying the nature of the abnormal brain tissue. For several decades humankind has preferred non-invasive methods in establishing a definite pathological diagnosis. This is particularly true for cerebral lesions. This study appears to indicate, that one is now justified, in carrying out larger studies to confirm the present findings that MRS could be a valuable diagnostic tool in identifying certain types of cerebral pathology. CLINICAL APPLICATIONS & SUGGESTIONS: This study has enabled development of a few guidelines in the use of MR spectroscopy, as an add-on modality, to improve diagnostic accuracy, in certain categories of lesions i.e. neoplasm versus nonneoplasm, high grade tumours versus low grade tumours, high grade tumours versus metastases, recurrent tumours versus radiation necrosis, cystic non-tumoural lesions versus cystic tumours and improved follow up of polyphasic demyelinating conditions i.e. multiple sclerosis. 1. It is desirable that all patients with intra cranial space occupying lesions referred for MRI also undergo MRS, to provide additional information which may help differentiate a neoplasm from nonneoplasms. This could avoid surgical treatment in some instances. 2. MRS can be considered as a suitable, complementary modality to be used when a doubt exists in defining whether a tumour is low or high grade. 3. Solitary metastasis always is difficult to diagnose and may be confused with other high grade tumours. While it is challenging to use single voxel MRS technique to distinguish between the two, MV-MRS technique would be more useful to differentiate metastasis from high grade glioma. 4. In follow up of treated patients of brain tumour, especially after surgery, radiotherapy and/or chemotherapy, the differentiation between recurrent tumour and radiation necrosis can be difficult. Making this distinction is critical for treatment and MRS appears to be a useful tool to distinguish between the two. 5. In analyzing the use of MRS in tuberculous and pyogenic abscess, MRS was found to be useful in distinguishing tuberculous from pyogenic abscesses. 6. In polyphasic demyelinating conditions such as Multiple Sclerosis, MRS plays a valuable role not only in initial diagnosis but also in follow up. Degree of neuronal loss, a prognostic factor, can indirectly be titrated through MRS findings on follow up studies.

Item Type: Thesis (Doctoral)
Uncontrolled Keywords: Proton Magnetic Resonance Spectroscopy, Intracranial Lesions, Tumours, Brain Lesion Characterization.
Subjects: Respiratory Medicine > Neurology
> Respiratory Medicine > Neurology
Depositing User: Subramani R
Date Deposited: 16 Jun 2017 07:19
Last Modified: 22 Sep 2022 10:14

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