Noninvasive study of brain tumours metabolism using phosphorus-31 magnetic resonance spectroscopy.

Phosphorus-31 magnetic resonance spectroscopy (31P MRS) is currently not accepted as a diagnostic tool in the neuro-oncological practice, although it provides useful non-invasive information about biochemical processes ongoing in the intracranial tumours. This pilot study was aimed to present the diagnostic capability of the 31P MRS in brain tumour examination, even its application on clinical 1.5T MR scanner.Seven patients with brain tumorous lesions (four glioblastomas, one ependymoma, and two lung metastasis) underwent multivoxel in vivo 31P MRS performed on clinical 1.5 T MR scanner within measurement time of 20 minutes. Comparing two selected voxels, one in the tumour and the other one in the normal-appearing brain tissue, enabled to investigate their metabolic differences. Enhanced markers of membrane phospholipids synthesis (significantly increased phosphomonoesters ratios) than markers of their degradation (significantly decreased phosphodiesters ratios) manifested a higher cell proliferation ongoing in tumours. High energetic tumorous tissue demands leading to anaerobic metabolic turnover were present as a significant decline in phosphocreatine ratios and adenosine triphosphates. Intracellular pH evaluation showed a tumorous tendency to alkalize. 31P MRS enables the non-invasive metabolic characterization of intracranial tumours and thus appears to be a clinically useful method for the determination of ongoing tumour pathomechanisms (Fig. 2, Ref. 26). Keywords: brain tumour, 31P MRS, 1.5 Tesla; energetic metabolism.

Hypothalamic damage in multiple sclerosis correlates with disease activity, disability, depression, and fatigue.

OBJECTIVES: Disturbances in the hypothalamo-pituitary axis are supposed to modulate activity of multiple sclerosis (MS). We hypothesised that the extent of HYP damage may determine severity of MS and may be associated with the disease evolution. We suggested fatigue and depression may depend on the degree of damage of the area. METHOD: 33 MS patients with relapsing-remitting and secondary progressive disease, and 24 age and sex-related healthy individuals (CON) underwent 1H-MR spectroscopy (1H-MRS) of the hypothalamus. Concentrations of glutamate + glutamin (Glx), cholin (Cho), myoinositol (mIns), N-acetyl aspartate (NAA) expressed as ratio with creatine (Cr) and NAA were correlated with markers of disease activity (RIO score), Multiple Sclerosis Severity Scale (MSSS), Depressive-Severity Status Scale and Simple Numerical Fatigue Scale. RESULTS: Cho/Cr and NAA/Cr ratios were decreased and Glx/NAA ratio increased in MS patients vs CON. Glx/NAA, Glx/Cr, and mIns/NAA were significantly higher in active (RIO 1-2) vs non-active MS patients (RIO 0). Glx/NAA and Glx/Cr correlated with MSSS and fatigue score, and Glx/Cr with depressive score of MS patients. In CON, relationships between Glx/Cr and age, and Glx/NAA and fatigue score were inverse. CONCLUSION: Our study provides the first evidence about significant hypothalamic alterations correlating with clinical outcomes of MS, using 1H-MRS. The combination of increased Glu or mIns with reduced NAA in HYP reflects whole-brain activity of MS. In addition, excess of Glu is linked to severe disease course, depressive mood and fatigue in MS patients, suggesting superiority of Glu over other metabolites in determining MS burden.

A new approach in DCE MRI data analysis for differentiating benign and malignant breast lesions.

BACKGROUND: Dynamic contrast enhanced MRI (DCE MRI) is able to reflect changes in vascularity, vessel permeability and extracellular diffusion space of tissues. The goal of this study was to investigate the use of DCE MRI to differentiate benign and malignant breast lesions. PATIENTS AND METHODS: From a database, five patients with malignant and five patients with benign lesions were randomly chosen. All patients underwent measurement in a 3T MR scanner using a breast coil. A series of T1-weighted MRI were performed using an intravenously delivered contrast agent. Then, 17 postcontrast sets were acquired within a timeframe of 13 seconds. All DCE MRI data were evaluated using the JIM image analysis package. We observed changes in signal intensity over the acquisition time -  curves of dynamic contrast enhancement. CONCLUSION: We investigated parts of the curves with the largest increase in signal intensity during the timeframe. For further comparison, we used values of the highest signal intensity increases between the timeframes. Analysis of these results led to the proposal that the threshold between benign and malignant lesion had a relative value of 100. Furthermore, there was a significant difference between these two types of lesions.

Clinical correlations of proton magnetic resonance spectroscopy findings in acute phase after mild traumatic brain injury.

INTRODUCTION: Standard brain magnetic resonance imaging (MRI) is typically normal in most patients after mild traumatic brain injury (MTBI). Proton magnetic resonance spectroscopy (¹H-MRS) is more sensitive to detect subtle post-traumatic changes. The aim of the study was to evaluate the clinical correlations of these changes in the acute phase (within 3 days) after MTBI. METHODS: Twenty-one patients with MTBI and 22 controls were studied. Both groups underwent neuropsychological testing and single-voxel ¹H-MRS examination of both frontal lobes and upper brainstem. RESULTS: Significant decrease in NAA was found in both frontal lobes and in NAA/Cre ratio in the right frontal lobe (p < 0.05). Correlation analysis showed a correlation of NAA in the left frontal lobe with Backward Digit Span (p = 0.022) and Stroop test A (p = 0.0034) and a weak correlation with TMT B time (p = 0.046). The NAA/Cre in the right frontal lobe correlated with Stroop test A (p = 0.007) and with the total score of Digit Span (p = 0.016). Lower NAA was found in the upper brainstem (p = 0.0157) in the sub-group of patients with post-traumatic unconsciousness. CONCLUSIONS: This study found a correlation of ¹H-MRS metabolite changes with cognitive decline and presence or absence of loss of consciousness in the acute phase after MTBI.