ABSTRACT
PURPOSE: To assess the metabolite ratios in gliomas to determine whether the metabolic information obtained by using by using in vivo single vexel 1H magnetic resonance spectroscopy(MRS) can be used as a marker for the grading of malignancy. MATERIALS AND METHODS: A total of 28 1H MR spectra from brain tumors in 27 patients with pathologically-proven gliomas were recorded. Seven patients had low grade gliomas (grade II astrocytoma in three, oligodendroglioma in three and mixed glioma in one), six had anaplastic gliomas (grade III astrocytoma in three and oligodendroglioma in three), and 14 had glioblastoma multiformes (grade IV), 1H MRS was performed on a 1.5T MRunit using PRESS sequence with a TR of 2000ms, a TE of 270 or 135ms and a voxel size of cm for all spectra. Relative lactate levels, NAA/Cho, NAA/Cr and Cho/Cr ratios were measured based on the peak heights of each resonance and compared among gliomas. RESULTS: Most tumors demonstrated decreased NAA, elevated Cho and lactate. Relatively high lactate and Cho levels and markedly decreased NAA level were more frequently observed in the high grade gliomas than in low grade gliomas. Marked elevation of lactate level in the solid component of the tumor was mostly observed in high grade gliomas. In a patient with gliomatosis cerebri, 1H MRS demonstrated a spectral pattern of tumor in filtration in an area that on MR images was apparently normal. However, NAA/Cr, NAA/Cho and Cho/Cr ratios did not significantly correlate, however, with the histologic grading of malignancy. Because of the partial volume effect, the heterogeneity of tumors containing solid and cystic or necrotic components within avoxel limited the interpretation of 1H MRS data for the grading of malignancy. CONCLUSION: The results suggest that in some patients in vivo single voxel 1H MRS may be useful for grading the malignancy of gliomas and evaluating the exact extent of tumors. In solid gliomas, the relative level of lactate appears to be a good markerfor the grading of malignancy.
Subject(s)
Humans , Astrocytoma , Brain Neoplasms , Filtration , Glioblastoma , Glioma , Lactic Acid , Magnetic Resonance Spectroscopy , Neoplasms, Neuroepithelial , Oligodendroglioma , Population CharacteristicsABSTRACT
PURPOSE: To determine whether 1H magnetic resonance spectroscopy (MRS) is useful in differentiating idiopathic Parkinson's disease (IPD) from progressive supranuclear palsy (PSP), based on metabolite ratios. MATERIALS AND METHODS: Using a 1.5 T MR Unit, single voxel 1H MRS using STEAM with a TR of 2000ms and a TE of 135ms was performed in seven PD and eight PSP patients. Five age-matched volunteers(mean age, 63 years) andanother five younger healthy volunteers(mean age, 30 years) were studied as normal controls. The regions of interest were the putamen and pallidum, with a size of 2 X 2 X 2cm. After measuring the spectral intensities ofeach metabolite (N-acetylaspartate=NAA, choline=Cho, creatine=Cr and lactate), relative peak height ratios ofNAA/Cr, Cho/Cr and Naa/Cho, and lactate levels among four groups were compared. ESULTS: NAA/Cho and NAA/Crratios were statistically lower in the PSP group than the IPD group (1.21 +/-0.26 versus 1.45 +/-0.20, and 1.26 +/-.23 versus 1.38 +/-0.19, respectively : p0.05). Cho/Cr ratios were not different among four groups. Lactate was not detectedin any patients. CONCLUSION: NAA/Cho and NAA/Cr ratios in the corpus striatum were significantly lower in the PSP group than in the age-matched control and IPD groups. These results suggest that loss of neuron cells in thecorpus striatum is more prominent in PSP than in IPD, and that NAA/Cho and NAA/Cr ratios may help in differential diagnosis of IPD and PSP.
Subject(s)
Humans , Corpus Striatum , Lactic Acid , Magnetic Resonance Spectroscopy , Neurons , Parkinson Disease , Putamen , Steam , Supranuclear Palsy, ProgressiveABSTRACT
PURPOSE: To evaluate regional differences of 1H magnetic resonance(MR) spectral patterns in normal adulthuman brains. MATERIALS AND METHODS: A total of 44 1H MR spectra in 25 volunteers aged 27-45 were obtained infive regions including the frontal lobe(10), parietal lobe(10), temporal lobe(5), basal ganglia(10) and thalamus(9). 1H MR spectroscopy(MRS) was performed using a PRESS sequence with a TR of 2000ms and a TE of 270msfrom a volume of cm on a 1.5T clinical MR unit. Relative metabolite ratios of NAA/Cho, NAA/Cr and CR/Cho in eachregion were measured and compared. RESULTS: A total of 44 reliable spectra were successfully obtained in allregions. NAA/Cho, NAA/Cr and Cr/Cho ratios varied considerably, ranging from 1.09 +/-0.2 to 2.46 +/-0.25, from1.72 +/-0.35 to 2.45 +/-0.25 and from 0.64 +/-0.1 to 1.01 +/-0.12, respectively. Significant regional difference sin metabolite ratios were observed; higher NAA/Cho and NAA/Cr ratios in the parietal lobe, lower NAA/Cho ratios inthe temporal lobe, and lower Cr/Cho ratios in the temporal lobe compared to those of other regions(p<0.05). Differences in metabolite ratios between the right and left frontal lobes, and between the right and left basalganglias were not significant. CONCLUSION: 1H MR spectra of the normal adult human brains using in vivo singlevoxel 1H MRS represented significant regional differences in metabolite ratios of NAA/Cho, NAA/Cr and Cr/Cho. Our1H MR spectroscopic results are a useful ueference for assessing the 1H MRS pattern of various intracranial diseases.