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1.
Acute liver failure (ALF)-related encephalopathy was previously characterized by MR spectroscopy of single voxels containing both grey and white matter brain tissue. Quantitative multivoxel MRS was used here to compare grey and white matter brain tissue concentrations of glutamate/glutamine (Glx) and lactate in ALF and associate the results with other liver function parameters. Five pediatric patients with ALF-related encephalopathy and five controls, examined after successful liver transplantation, were examined by brain MRI/MRS. ALF patients had higher Glx and lactate concentrations in brain white matter than controls (Glx + 125%: P < 0.01; lactate + 33%, P < 0.05) and higher Glx in grey matter (Glx + 125%: P < 0.01). Within the group of ALF patients positive correlations were found between grey or white matter lactate concentration and serum ammonia (P < 0.05), and negative correlations between grey or white matter Glx and venous pH (P < 0.001). This is the first study presenting evidence of high Glx levels in both white and grey matter brain tissue in ALF-related encephalopathy. The elevations in CNS Glx and lactate concentrations appear to relate to hepatic detoxification (ammonia, venous pH), rather than to liver parenchymal integrity (aspartate aminotransferase, alanine aminotransferase) or biliary cholestasis (bilirubin, γ-glutamyl transpeptidase, alkaline phosphatase).  相似文献   

2.
This study was aimed to clarify some ambiguities in the interpretation of proton magnetic resonance spectroscopy (1H-MRS) of meningiomas. The cases of 31 meningioma patients (27 benign and 4 nonbenign meningiomas) that underwent single-voxel 1H-MRS (PRESS sequence, TR/TE = 2,000 ms/68, 136, 272 ms) were retrospectively analyzed. To verify the findings of in-vivo study, phantoms were measured, and pathological sections of 11 patients were reviewed. All meningiomas demonstrated increased choline and decreased creatine, except for a lipomatous meningioma that only displayed a prominent lipid (Lip) peak. Alanine (Ala) and lactate (Lac) coexisted in eight cases, indicating an alternative pathway of energy metabolism in meningiomas. They partially overlapped with each other and demonstrated a triplet-like spectral pattern, which was consistent with phantom study. Glutamine/glutamate (Glx) was helpful for the recognition of meningioma when Ala was absent. N-acetyl compounds(NACs) were observed in nine cases whose voxels were completely limited within the tumors, indicating that meningiomas might have endogenous NACs. Lac was indicative of an aggressive meningioma, although not always a nonbenign one. Lip not only represented micronecrosis in nonbenign meningiomas, but also reflected microcystic changes or fatty degeneration in benign meningiomas. 1H-MRS reflects some distinctive biochemical and pathological changes of meningiomas that might be misinterpreted. Grant: This study was supported by the Japan-China Sasakawa Medical Fellowship (Nippon Foundation, Japan)  相似文献   

3.
PURPOSE: To prospectively define proton magnetic resonance spectroscopy (MRS) findings of meningiomas, and describe the ability or inability of short- and long-echo MRS to differentiate typical and atypical meningiomas in vivo. MATERIAL AND METHODS: Seventeen patients with pathologically confirmed typical meningiomas and six with atypical meningiomas were evaluated with conventional MR imaging and MRS before resection. MRS studies using point-resolved spectroscopy (PRESS) localisation, at short- and long-echo time (TR 2000 ms, TE: 30 and 144 ms, 64-96 acquisition) were acquired on a 1.5 T scanner. MRS data obtained from these patients were compared with histopathological findings. Mean cellular proliferation (MIB-1) antibody staining against the Ki-67 antigen was also determined in all meningiomas. RESULTS: Prominent choline (Cho) was present in all meningiomas. Alanine (Ala) was observed in 21 cases of the 23 meningiomas. Acetylaspartate (NAA) and creatine (Cr) were either not observed or detected in minimal amounts in at all both groups of meningiomas on long TE (144 ms) spectra. The mean Cho/Cr values in the four atypical meningiomas were 4.44+/-0.30 (mean+/-standard deviation) and 3.39+/-0.52 in the 12 typical meningiomas on short TE spectra. Cho/Cr ratio could not be determined in the other seven cases because of a lack of creatine peak. Of the five meningiomas in which a lactate peak was detected, four were in typical cases and only one was in atypical meningioma. Mean MIB-1 proliferation index was 3.7% in typical meningiomas and 10% in atypical meningiomas. CONCLUSION: Prominent Cho, absence or low amount of NAA and Cr, and presence of Ala were common characteristics of spectral pattern of both atypical and typical meningiomas on MRS. MRS cannot reliably differentiate typical intracranial meningiomas from atypical meningiomas preoperatively. Mean MIB-1 proliferation index was well correlated with histopathology findings.  相似文献   

4.
Our aim was to evaluate the usefulness of proton MR spectroscopy ((1)H MRS) in the diagnosis of radiologically atypical brain meningiomas. We studied 37 patients with intracranial meningiomas with MRI and (1)H MRS (TE 136 ms). Their spectra were quantitatively assessed and compared with those of 93 other intracranial brain neoplasms: 15 low-grade and 14 anaplastic astrocytomas, 30 glioblastomas and 34 metastases. The most characteristic features of meningiomas were the presence of alanine, high relative concentrations of choline and glutamine/glutamate and low concentrations of creatine-containing compounds, N-acetyl-containing compounds and lipids. These resonances were assembled in algorithms for two-way differentiation between meningioma and the other tumours. The performance of the algorithms was tested in the 130 patients using the leave-one-out method, with 94% success in differentiating between meningioma and other tumour. Of the 37 meningiomas, five (14%) were thought atypical on MRI, and in only one of these, found to be malignant on histology, was a diagnosis other than meningioma suggested by the algorithm. The other four were correctly classified. We suggest that (1)H MRS provides information on intracranial meningiomas which may be useful in diagnosis of radiologically atypical cases.  相似文献   

5.
We report a case of proton magnetic resonance spectroscopy (MRS) of hemangioblastoma in a 56-yearold man with a history of hyperlipidemia who was suffering from an equilibrium disorder. Proton MRS revealed a high mobile lipids (Lip) peak between 0.9 and 1.4 ppm, which was compatible with histologically proven lipids in the tumor. No lactate peak was recognized. The creatine/phosphocreatine peak was low. Choline-containing compounds were increased. The N-acetylaspartate peak was absent, which indicated that the tumor is of nonneurogenic origin. Combined with the absence of the necrotic component on magnetic resonance imaging, this Lip peak on proton MRS could be the characteristic pattern of hemangioblastoma. These unique results of proton MRS can play an important role in the differential diagnosis of intracranial hemangioblastoma. However, further investigations are required to establish the typical characteristics of proton MRS of hemangioblastoma.  相似文献   

6.
Introduction  This study was aimed to investigate the relationship between quantitative proton magnetic resonance spectroscopy (1H-MRS) and pathological changes in meningioma. Materials and methods  Twenty-two meningioma cases underwent single voxel 1H-MRS (point-resolved spectroscopy sequence, repetition time/echo time = 2,000 ms/68, 136, 272 ms). Absolute choline (Cho) concentration was calculated using tissue water as the internal reference and corrected according to intra-voxel cystic/necrotic parts. Pathological specimens were stained with MIB-1 antibody to measure cell density and proliferation index. Correlation analysis was performed between absolute Cho concentration and cell density and MIB-1 labeled proliferation index. Results  Average Cho concentration of all meningiomas before correction was 2.95 ± 0.86 mmol/kg wet weight. It was increased to 3.23 ± 1.15 mmol/kg wet weight after correction. Average cell density of all meningiomas was 333 ± 119 cells/HPF, and average proliferation index was 2.93 ± 5.72%. A linear, positive correlation between cell density and Cho concentration was observed (r = 0.650, P = 0.001). After correction of Cho concentration, the correlation became more significant (r = 0.737, P < 0.001). However, no significant correlation between Cho concentration and proliferation index was found. There seemed to be a positive correlation trend after correction of Cho concentration but did not reach significant level. Conclusion  Absolute Cho concentration, especially Cho concentration corrected according to intra-voxel cystic/necrotic parts, reflects cell density of meningioma. Grant: This study was supported by the Japan-China Sasakawa Medical Fellowship (Nippon Foundation, Japan)  相似文献   

7.
We report preliminary experience using single-voxel, proton MR spectroscopy (MRS) employing small voxels of interest, in combination with short and long echo-time protocols, for the assessment of primary intracranial tumors in children. We examined 23 children with primary intracranial tumors detected by MRI, and 32 controls with similar ages, using MRS on a 1.5 T system. Localized single-voxel (3.7±1.3 cc) proton spectra were obtained with short-echo (2,000/18), stimulated-echo (STEAM) and long-echo (2,000/270) spin-echo (PRESS) protocols. All spectra were evaluated qualitatively; 10 tumor and 19 control spectra were processed for peak area quantification. Small voxels of interest were able to account for tissue heterogeneity. Combined acquisition of short- and long-echo spectra increased the number of detectable metabolites. The solid portion of all tumors exhibited reducedN-acetyl-aspartate (NAA), strong contribution from cholines (Cho) and inositols or glycine, minimal presence of total creatine (tCr), enhanced broad mobile lipid resonances and accumulated lactate. Calculated selected metabolite ratios of Cho/tCr and Cho/NAA were substantially increased from control values. The cystic portions of the masses showed only lipid and lactate peaks.  相似文献   

8.
The purpose of this study was to correlate magnetic resonance imaging (MRI)-based lesion load assessment with clinical disability in early relapsing remitting multiple sclerosis (RRMS). Seventeen untreated patients (ten women, seven men; mean age 33.0 ± 7.9 years) with the initial diagnosis of RRMS were included for cross-sectional as well as longitudinal (24 months) clinical and MRI-based assessment in comparison with age-matched healthy controls. Conventional MR sequences, MR spectroscopy (MRS) and magnetisation transfer imaging (MTI) were performed at 1.5 T. Lesion number and volume, MRS and MTI measurements for lesions and normal appearing white matter (NAWM) were correlated to clinical scores [Expanded Disability Status Scale (EDSS), Multiple Sclerosis Functional Composite (MSFC)] for monitoring disease course after treatment initiation (interferon β-1a). MTI and MRS detected changes [magnetisation transfer ratio (MTR), N-acetylaspartate (NAA)/creatine ratio] in NAWM over time. EDSS and lesional MTR increases correlated throughout the disease course. Average MTR of NAWM raised during the study (p < 0.05) and correlated to the MSFC score (r = 0.476, p < 0.001). At study termination, NAA/creatine ratio of NAWM correlated to the MSFC score (p < 0.05). MTI and MRS were useful for initial disease assessment in NAWM. MTI and MRS correlated with clinical scores, indicating potential for monitoring the disease course and gaining new insights into treatment-related effects. J. Bellmann-Strobl, H. Stiepani and J. Wuerfel contributed equally to this work.  相似文献   

9.
Glutathione has major roles in removing free radicals and toxins from normal tissues, but its presence in tumor cells hinders the effectiveness of many anticancer therapies. Analysis of short echo time brain tumor (1)H spectra at 1.5 T using a linear combination of metabolite spectra (LCModel) suggested a significant contribution of glutathione to meningioma spectra. By in vivo MRS (TE = 30 ms, TR = 2020 ms), reduced glutathione was found to be significantly elevated in meningiomas (3.3 +/- 1.5 mM, Mann Whitney, P < 0.005) compared to normal white matter (1.2 +/- 0.15 mM) and low-grade gliomas (1.0 +/- 0.26 mM), in agreement with published histofluorescence studies of tumor biopsies. Glx concentrations were also found to be elevated in meningiomas compared to astrocytomas or normal white matter, indicative of metabolic differences. The ability to noninvasively quantify reduced glutathione in vivo may aid selection of treatment therapies and also provide an indication of tumor aggressiveness.  相似文献   

10.
PURPOSETo assess the use of in vivo proton MR spectroscopy for characterization of intracranial mass lesions and to ascertain its reliability in grading of gliomas.METHODSOne hundred twenty patients with intracranial masses were subjected to volume selective spectroscopy using stimulated echo acquisition mode (echo time, 20 and 270 milliseconds) and spin echo (echo time, 135 milliseconds) sequences. The intracranial lesions were grouped into intraaxial and extraaxial, as judged with MR imaging. Assignment of resonances was confirmed in two samples each of brain abscess, epidermoid cyst, and tuberculoma using ex vivo high-resolution MR spectroscopy.RESULTSThe in vivo spectra appeared distinct compared with normal brain in all the cases. All high-grade gliomas (n = 37) showed high choline and low or absent N-acetyl-L-aspartate and creatine along with lipid and/or lactate, whereas low-grade gliomas (n = 23) were characterized by low N-acetyl-aspartate and creatine and high choline and presence of only lactate. N-acetyl-aspartate/choline ratio was significantly lower and choline/creatine ratio was significantly higher in high-grade gliomas than in low-grade gliomas. Presence of lipids suggested a higher grade of malignancy. All metastases (n = 7) showed lipid and lactate, whereas choline was visible in only four cases. Epidermoids showed resonances from lactate and an unassigned resonance at 1.8 ppm. Meningiomas could be differentiated from schwannomas by the presence of alanine in the former. Among the infective masses, pyogenic abscesses (n = 6) showed resonances only from cytosolic amino acids, lactate, alanine, and acetate; and tuberculomas (n = 11) showed only lipid resonances.CONCLUSIONSIn vivo proton MR spectroscopy, helps in tissue characterization of intracranial mass lesions. Spectroscopy is a reliable technique for grading of gliomas when N-acetyl-aspartate/choline and choline/creatine ratios and presence of lipids are used in combination.  相似文献   

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