Magnetic Resonance Spectroscopy Metabolite Ratios Research Articles

Magnetic Resonance Spectroscopy of Intra-axial Gliomas With Histopathological Correlation in a Tertiary Care Center of Eastern Nepal.

Background and objective Magnetic resonance spectroscopy (MRS) is a magnetic resonance imaging technique used to identify in vivo metabolites non-invasively within the tissue of interest. It plays an important role in diagnosing brain lesions, particularly tumors and infections. There are certain metabolites whose levels are increased or decreased in brain tumors, the ratios of which can also be used to grade the tumors as high- or low-grade. This study aimed to assess the spectrum of different metabolites in intraaxial gliomas using magnetic resonance spectroscopy and to assess the usefulness of their ratios for grading gliomas into high-grade and low-grade. Methods This descriptive cross-sectional study was performed in the radiology department of Nobel Medical College and Teaching Hospital, Biratnagar, Nepal over one year (September 2019 to September 2020). Thirty-five patients diagnosed as having intra-axial tumors were enrolled. After taking informed consent the examination findings were recorded in structured proforma. Siemens' 3 Tesla open magnet MAGNETOM Skyra (Siemens Healthineers AG, Munich, Germany) MR scanner was used to evaluate each patient. Data was analyzed using the software Statistical Package for Social Sciences (SPSS), version 26.0 (IBM Corp., Armonk, NY). Results Out of 35 patients scanned, 18 had high-grade glioma and 17 had low-grade glioma. High-grade glioma had a choline/creatine (Cho/Cr) ratio of 2.44 ± 0.78 and a choline/N-acetyl-aspartate (Cho/NAA) ratio of 2.05 ± 0.84. Low-grade glioma had a Cho/Cr ratio of 1.48 ± 0.50 and a Cho/NAA ratio of 1.41 ± 0.19. Fourteen out of eighteen high-grade gliomas had raised lipid/lactate peaks. The sensitivity, specificity, positive and negative predictive values (PPV and NPV), and accuracy for diagnosing high-grade glioma with a Cho/Cr ratio cut-off of 1.5 was 83.3 %, 82.4%, 83.3%,82.4 %, and 82.85% respectively. Conclusion MRS metabolite ratios can be used to diagnose and grade gliomas. Cho/Cr, Cho/NAA, and the presence or absence of lipid/lactate peak can significantly improve the sensitivity, specificity, predictive values, and accuracy of preoperative glioma grading when used in conjunction with conventional MRI.

The evaluation of Hashimoto's thyroiditis with event-related potentials and magnetic resonance spectroscopy and its relation to cognitive function

Thyroid dysfunction is very often accompanied by cognitive and affective disorders. The frequency of these disorders in patients with compensated Hashimoto’s thyroiditis (HT) is unknown. The aim of the present study was to evaluate brain dysfunction in euthyroid HT patients by means of event-related potentials (ERP) and magnetic resonance spectroscopy (MRS) and to correlate it with cognitive function. 68 patients with HT (59 female, 9 male) and 45 healthy controls were included in the study. All the patients underwent ERP including an analysis of N200 and P300 response parameters. MRS voxels were located in the posterior cingulate gyrus (PCG) and the left parietal white matter (PWM). The NAA/Cr, mI/Cr, and Cho/Cr ratios were analysed. The ERP parameters, MRS metabolite ratios and hormonal concentrations (TSH, fT3, fT4) as well as TGAb and TPOAb titer were also correlated. There was a significant prolongation of the latencies of N200 and P300 potentials and a significant decrease of P300 amplitude in HT patients than in the control group. There was a significant positive correlation between the mI/Cr ratio in the PCG area and P300 latencies. NAA/Cr ratio in the PCG region showed significant negative correlations with all N200 latencies. The results may suggest brain dysfunction in neurologically asymptomatic HT patients. ERPs undergo significant changes in patients with HT and may, in combination with MRS, constitute an important element in the recognition and monitoring of cognitive functions in this group of patients.

8.8 Neonatal Encephalopathy in the Cooling Therapy era – Preliminary Cerebral Magnetic Resonance results from the Marble Consortium

BackgroundAlthough cerebral metabolic changes during neonatal encephalopathy (NE) have been well characterised using magnetic resonance spectroscopy (MRS) in single-centre studies, the widespread effect of therapeutic hypothermia is less clear.ObjectiveTo describe...

Magnetic Resonance Spectroscopy at Term-Equivalent Age in Extremely Preterm Infants: Association With Cognitive and Language Development

BackgroundProton magnetic resonance spectroscopy can be used to assess brain integrity and maturation with age. ObjectiveTo compare regional cerebral magnetic resonance spectroscopy metabolite ratios in extremely low birth weight and healthy term control infants measured at term-equivalent age and to evaluate association between magnetic resonance spectroscopy metabolites and cognitive and language development at 18-22 months' corrected age. MethodsSingle-voxel point-resolved spectroscopy sequence was performed in a prospective cohort of 43 infants. Magnetic resonance spectroscopy metabolite ratios of N-acetylaspartate to choline-containing compounds and N-acetylaspartate to myo-inositiol in the hippocampus, cortex, and subventricular zone were associated with Bayley mental, cognitive, and language scores at 18-22 months' corrected age. ResultsThe mean (±S.D.) gestation of the 31 extremely low birth weight population was 25 (±1.1) weeks and mean (±S.D.) birth weight was 749 (±133.9) g. Compared with healthy term control infants, extremely low birth weight infants exhibited consistently lower N-acetylaspartate-to-choline-containing compounds ratios in our three regions of interest, with differences reaching statistical significance for the subventricular zone and cortex regions. In multiple linear regression analyses, N-acetylaspartate-to-choline-containing compounds ratio in the subventricular zone, N-acetylaspartate-to-choline-containing compounds ratio in the cortex, and N-acetylaspartate-to-myo-inositiol ratio in the subventricular zone were significantly associated with Bayley mental scores at 18-22 months' corrected age. ConclusionsMagnetic resonance spectroscopy metabolite abnormalities at term-equivalent age appear to be significantly associated with cognitive and language development in extremely low birth weight infants.

Neurochemical alterations of the entorhinal cortex in amnestic mild cognitive impairment (aMCI): A three-year follow-up study

The neurochemical alterations in the entorhinal cortex have not yet been measured, even though the entorhinal cortex is the earliest involved brain region in aMCI. In this study, we investigated whether brain regions including the entorhinal cortex would show early involvement of neurochemical abnormalities in aMCI, and whether magnetic resonance spectroscopy (MRS) abnormalities might be a predictive marker of conversion of aMCI to Alzheimer's disease (AD). MRS was performed on 13 aMCI patients and 11 patients with no cognitive impairment (NCI). Localizing voxels were placed within the entorhinal cortex, hippocampus, posterior cingulate gyrus, and occipital white matter in the dominant hemisphere. N-acetyl aspartate/creatinine (NAA/Cr) ratios in the entorhinal cortex were significantly lower in aMCI patients than in NCI subjects. After a three-year follow-up, seven aMCI patients converted to AD and six remained stable. Baseline NAA/Cr ratios of entorhinal cortex were decreased in converters, compared to NCI. Our study suggested the entorhinal cortex is the earliest site that is subject to neurochemical alteration in aMCI patients, and baseline MRS metabolite ratios in the entorhinal cortex can be a marker for predicting conversion of aMCI to AD.

Comparative Prognostic Utilities of Early Quantitative Magnetic Resonance Imaging Spin-Spin Relaxometry and Proton Magnetic Resonance Spectroscopy in Neonatal Encephalopathy

We sought to compare the prognostic utilities of early MRI spin-spin relaxometry and proton magnetic resonance spectroscopy in neonatal encephalopathy. Twenty-one term infants with neonatal encephalopathy were studied at a mean age of 3.1 days (range: 1-5). Basal ganglia, thalamic and frontal, parietal, and occipital white matter spin-spin relaxation times were determined from images with echo times of 25 and 200 milliseconds. Metabolite ratios were determined from an 8-mL thalamic-region magnetic resonance spectroscopy voxel (1H point-resolved spectroscopy; echo time 270 milliseconds). Outcomes were assigned at age 1 year as follows: (1) normal, (2) moderate (neuromotor signs or Griffiths developmental quotient of 75-84), (3) severe (functional neuromotor deficit or developmental quotient <75 or died). Predictive efficacies for differentiation between normal and adverse (combined moderate and severe) outcomes were compared by receiver operating characteristic curve analysis and logistic regression. Thalamic and basal ganglia spin-spin relaxation times correlated positively with outcome and predicted adversity. Although thalamic and basal ganglia spin-spin relaxation times were prognostic of adversity, magnetic resonance spectroscopy metabolite ratios were better predictors, and, of these, lactate/N-acetylaspartate was most accurate. Deep gray matter spin-spin relaxation time was increased in the first few days after birth in infants with an adverse outcome. Proton magnetic resonance spectroscopy was more prognostic than spin-spin relaxation time, with lactate/N-acetylaspartate the best measure. Nevertheless, both techniques were useful for early prognosis, and the potential superior spatial resolution of spin-spin relaxometry may define better the precise anatomic pattern of injury in the early days after birth.

66. Late effects of CNS prophylactic irradiation in childhood due to LLA using Magnetic Resonance Spectro-skopy. (preliminary report)

Purpose The aim of this study was to evaluate changes in magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) of the brain in survivars with Acute Lymphoblastic Leukemia to assess neurotixicity follow profilactic brain irradiation. Methods Ten from 100 patients with LLA treated in Department of Pediatric Hematology from 1990 to 1995 and irradiated in Centre of Oncology were icluded in MRI and MRS studies. The study group included 6 male and 4 female. All patients had been irradiated for brain using fraction dose of 1,8 Gy up to total dose of 18 Gy and had recived MTX based chemotherapy in doses depending on level of risk. Two of them were included in low risk and eight in intermediate risk. Results MRI of brain was abnormal in 5 cases. There were mild white matter changes. The changes were Been in H- MRS metabolite ratios. In one of these cases we observed a impair of verbal functions. Conclusions The MRS could be valuable method to access brain tissue metabolism after radiotherapy. That noninvasive method may be recomended for children with LLA to observe neurotoxicity of profilactic irradiation.