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Objective To explore the spatial distribution of abnormal brain areas and metabolic changes in Alzheimer's disease (AD),and provide a reference for early clinical diagnosis of AD.Methods Sixteen cases of AD patients and 1 6 healthy controls (HC)underwent multi-voxel 1H-MRS examination with semi-LASER sequence.The posterior cingulate gyrus section was localized as the volume of interest(VOI)level.The VOI consisted of bilateral posterior cingulate gyrus,occipital lobe cortex,lateral ventricle paratrigonal white matter and dorsal thalamus.N-acetylaspartate (NAA),creatine (Cr),choline (Cho),myo-inositol (MI)and glutamate-glutamine (Glx)concentration were measured.Differences in metabolite were compared between AD and HC groups.Relationships between metabolite and clinical mini-mental state examination(MMSE)score were analyzed.Results For metabolite index in VOI of right hemisphere:the AD group displayed significantly lower NAA,NAA/Cr,NAA/MI and higher MI,MI/Cr levels in posterior cingulate gyrus,lower NAA,Glx levels in occipital lobe cortex,lower NAA and higher Cho levels in dorsal thalamus.For metabolite index in VOI of left hemisphere:the AD group displayed significantly lower NAA,NAA/Cr,NAA/MI,Glx/Cr and higher MI/Cr levels in posterior cingulate gyrus,lower NAA and higher Cho/Cr levels in occipital lobe cortex,lower NAA and higher cho levels in lateral ventricle paratrigonal white matter,lower Glx and higher Cho levels in dorsal thalamus.NAA/Cr was positively correlated with Glx/Cr in left posterior cingulate gyrus in AD group.Conclusion NAA is decreased while MI is increased in posterior cingulate gyrus in AD patients.Cho is increased in both grey and white matter.Glx is decreased mainly within grey matter,involving both cortex and sub cortex structures.
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Objective • To determine clinical value of multi-voxel magnetic resonance spectroscopy (MVMRS) in the diagnosis of tongue carcinoma. Methods • A total of 56 cases that were pathologically diagnosed as having unilateral squamous cell carcinoma (SCC) or adenoid cystadenocarcinoma (ACC), from January to December 2017, were selected in this retrospective study. The characteristics of metabolic profiles in MVMRS were analyzed. The signals of choline (Cho), creatine (Cr), choline creatine ratio (Cho/Cr), and lactate/lipids (LL) and the apparent diffusion coefficient (ADC) were comparatively analyzed among the tumor parenchymal area, the paratumor area, and the contralateral control area in SCC/ACC group. The above indexes in the relative areas between SCC and ACC were also compared. Moreover, the relationship between the LL or Cho signal intensity with ADC in all the areas of two groups was investigated. Results • Higher Cho and LL signals were observed in the tumor parenchymal areas than those in the paratumor areas and the contralateral control areas in both SCC and ACC groups (P=0.000), while ADC values in the tumor parenchymal areas were obviously lower (P=0.000). Cho and LL signal intensities and ADC values in the paratumor areas were between the tumor parenchymal areas and contralateral control areas in both groups (P=0.000). However, no significant difference among the areas in Cr or Cho/Cr signal was found (P>0.01). There was no significant difference between SCC and ACC groups in the relative areas, either (P>0.01). The signal intensity of LL in the tumor parenchymal area in SCC group was negatively linearly correlated with the ADC value (P=0.000). Conclusion • MVMRS can detect the content of metabolites in tongue carcinoma, and LL and Cho signal intensities with ADC value can reflect the degree of tumor invasion in the paratumor areas.
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The technology of Magnetic Resonance Spectroscopy(MRS) is a newly-developed mean for analyzing some specific nucleus and their compounds making use of the principles of magnetic resonance and the effects of chemical shift. Currently, among MRS applications, proton magnetic resonance spectroscopy (1HMRS) is the most widely applied one developed from single voxel to three-dimensional multi-voxel scanning technique. It provides a lot of important information for clinical studies. This article mainly reviews the methods for absolute quantification measurement of brain metabolites using multi-voxel MRS.
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To evaluate the metabolic changes in normal adult brains due to alterations SENSE and NEX (number of excitation) by multi voxel MR Spectroscopy at 3.0 Tesla. The study group was composed of normal volunteers (5 men and 8 women) with a mean (+/- standard deviation) age of 41 (+/-11.65). Their ages ranged from 28 to 61 years. MR Spectroscopy was performed with a 3.0T Achieva Release Version 2.0 (Philips Medical System-Netherlands). The 8 channel head coil was employed for MRS acquisition. The 13 volunteers underwent multi voxel spectroscopy (MVS) and single voxel spectroscopy (SVS) on the thalamus area with normally gray matter. Spectral parameters were as follows: 15 mm of thickness; 230 mm of FOV (field of view); 2000 msecs of repetition time (TR); 288 msecs of echo time (TE); 110x110 mm of VOI (view of interest); 15x15x15 mm of voxel size. Multi voxel spectral parameters were made using specially in alteration of SENSE factor (1~3) and 1~2 of NEX. All MRS data were processed by the jMRUI 3.0 Version. There was no significant difference in NAA/Cr and Cho/Cr ratio between MVS and SVS likewise the previous results by Ross and coworkers in 1994. In addition, despite the alterations of SENSE factor and NEX in MVS, the metabolite ratios were not changed (F-value : 1.37, D.F : 3, P-value : 0.262). However, line-width of NAA peak in MVS was 3 times bigger than that in SVS. In the present study, we demonstrated that the alterations of SENSE factor and NEX were not critically affective to the result of metabolic ratios in the normal brain tissue.
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Adulto , Humanos , Masculino , Encéfalo , Cabeça , Espectroscopia de Ressonância Magnética , Análise Espectral , TálamoRESUMO
Objective To investigate the role of proton magnetic resonance spectroscopy (~1H-MRS) in accurate lateralization of temporal lobe epilepsy (TLE) and the factors which influenc ~1H-MRS in epileptogenic zones.Methods ~1H MRS and MRI were performed in 40 patients with TLE and 20 healthy volunteers by 1.5T MR/MRS system. The data of spectra of N-acetylaspartate (NAA), creatine+phosphocreatine (Cr) and choline-containing compounds (Cho) obtained from the medial regions of the temporal lobes were analyzed. Lateralization of TLE with ~1H-MRS was defined by the ratio of NAA/(Cho+Cr).Results The ratios of NAA/(Cho+Cr) both in epileptogenic zones (0.45?0.12) and contralateral regions (0.51?0.10) were lower than that in control group (0.58?0.09)( P0.05). There was significant difference in bilateral abnormal EEG between bilateral abnormal NAA/(Cho+Cr) and unilateral abnormal NAA/(Cho+Cr)( P