PURPOSE: To determine the optimal voxel volume covering the hippocampal area in single-voxel proton magnetic resonance (MR) spectroscopy and to evaluate the reproducibility of metabolite ratios of the spectra. MATERIALS AND METHODS: Localized single-voxel proton MR spectroscopy was applied to the right hippocampal area of five healthy volunteers at 1.5 T (Siemens Vision), using a standard head coil, and we employed the spin-echo or point resolved spectroscopy sequence. Voxel volume was changed from 1ml to 5ml but other operator-dependent measurement parameters were fixed, as follows: repetition time/echo time=1500/135 msec, number of scans=300. Using the same voxel volume, five consecutive measurements were obtained in each subject. Signal to noise ratio (SNR) of N-acetylaspartate (NAA), NAA / Choline containing compounds (Cho) and NAA / Cr (creatine and phosphocreatine) +Cho ratios were calculated for all 25 spectra. RESULTS: The SNR of NAA peaks increased significantly as voxel volume was increased to 3 ml (p < 0.01, Kruskal-Wallis test and Wilcoxon rank sum test). There were, however, no significant differences in values among the spectra obtained with voxel volumes of 3, 4 and 5 ml (p > 0.1) ; in those obtained with voxel volume of 2-4ml, the standard deviations of NAA / Cho (10.6-13.2% of mean values) were similar to those of NAA /Cr+Cho (8.5-13.2% of mean values). CONCLUSION: For spin-echo proton MR spectroscopy of the hippocampal area, the optimal voxel volume may be more than 3 ml in a setting of TR/TE=1500/135 msec and number of scans=300. In this situation, standard deviations of metabolite ratios may reach about 8-13% of mean values.
Choline ; Head ; Healthy Volunteers ; Magnetic Resonance Spectroscopy* ; Protons* ; Signal-To-Noise Ratio ; Spectrum Analysis

PURPOSE: To investigate the 3-bond and spatial connectivity of human brain metabolites by scalar coupling and dipolar nuclear Overhauser effect/enhancement (NOE) interaction through 2D- correlation spectroscopy (COSY) and 2D- NOE spectroscopy (NOESY) techniques. MATERIALS AND METHODS: All 2D experiments were performed on Bruker Avance 500 (11.8 T) with the zshield gradient triple resonance cryoprobe at 298 K. Human brain metabolites were prepared with 10% D2O. Two-dimensional spectra with 2048 data points contains 320 free induction decay (FID) averaging. Repetition delay was 2 sec. The Top Spin 2.0 software was used for post-processing. Total 7 metabolites such as N-acetyl aspartate (NAA), creatine (Cr), choline (Cho), glutamine (Gln), glutamate (Glu), myo-inositol (Ins), and lactate (Lac) were included for major target metabolites. RESULTS: Symmetrical 2D-COSY and 2D-NOESY spectra were successfully acquired: COSY cross peaks were observed in the only 1.0-4.5 ppm, however, NOESY cross peaks were observed in the 1.0-4.5 ppm and 7.9 ppm. From the result of the 2-D COSY data, cross peaks between the methyl protons (CH3(3)) at 1.33 ppm and methine proton (CH(2)) at 4.11 ppm were observed in Lac. Cross peaks between the methylene protons (CH2(3,H alpha)) at 2.50ppm and methylene protons (CH2,(3,HB)) at 2.70 ppm were observed in NAA. Cross peaks between the methine proton (CH(5)) at 3.27 ppm and the methine proton (CH(4,6)) at 3.59 ppm, between the methine proton (CH(1,3)) at 3.53 ppm and methine proton (CH(4,6)) at 3.59 ppm, and between the methine proton (CH(1,3)) at 3.53 ppm and methine proton (CH(2)) at 4.05 ppm were observed in Ins. From the result of 2-D NOESY data, cross peaks between the NH proton at 8.00 ppm and methyl protons (CH3) were observed in NAA. Cross peaks between the methyl protons (CH3(3)) at 1.33 ppm and methine proton (CH(2)) at 4.11 ppm were observed in Lac. Cross peaks between the methyl protons (CH3) at 3.03 ppm and methylene protons (CH2) at 3.93 ppm were observed in Cr. Cross peaks between the methylene protons (CH2(3)) at 2.11 ppm and methylene protons (CH2(4)) at 2.35 ppm, and between the methylene protons(CH2 (3)) at 2.11 ppm and methine proton (CH(2)) at 3.76 ppm were observed in Glu. Cross peaks between the methylene protons (CH2 (3)) at 2.14 ppm and methine proton (CH(2)) at 3.79 ppm were observed in Gln. Cross peaks between the methine proton (CH(5)) at 3.27 ppm and the methine proton (CH(4,6)) at 3.59 ppm, and between the methine proton (CH(1,3)) at 3.53 ppm and methine proton (CH(2)) at 4.05 ppm were observed in Ins. CONCLUSION: The present study demonstrated that in vitro 2D-COSY and NOESY represented the 3-bond and spatial connectivity of human brain metabolites by scalar coupling and dipolar NOE interaction. This study could aid in better understanding the interactions between human brain metabolites in vivo 2DCOSY study.
Aspartic Acid ; Brain ; Choline ; Creatine ; Glutamic Acid ; Glutamine ; Humans ; Lactic Acid ; Protons ; Spectrum Analysis

Water soluble extract (WSE) is an important index for the quality evaluation of Astragali Radix (AR). In this study, the WSE of the wild AR from Shanxi province (SX) and the cultivated AR from Gansu Province (GS) were compared. The WSEs of two types of AR were determined according to the appendix of Chinese pharmacopoeia. Then the WSEs were subjected to NMR analysis, and the obtained data were analyzed using HCA, PCA, OPLS-DA, microarray analysis, and Spearman rank analysis. In addition, the Pearson correlation of differential metabolites were also calculated. The results showed that the WSE content of GS-AR (37.80%) was higher than that of SX-AR (32.13%). The main constituent of WSE was sucrose, and other 18 compounds, including amino acids, organic acids, were also detected. Multivariate analysis revealed that SX-AR contained more choline, succinic acid, citric acid, glutamate, taurine and aspartate, while GS samples contained more sucrose, arginine and fumaric acid. In addition, the Pearson correlations between different metabolites of the two types of AR also showed apparent differences. The results suggested that the WSE of two types of AR differs not only in the content, but also in the chemical compositions. Thus, the cultivation way is important to the quality of AR. This study supplied a new method for the comparison of extract of herbal drugs.
Arginine ; analysis ; Aspartic Acid ; analysis ; Choline ; analysis ; Citric Acid ; analysis ; Drugs, Chinese Herbal ; analysis ; chemistry ; Fumarates ; analysis ; Glutamic Acid ; analysis ; Magnetic Resonance Spectroscopy ; Multivariate Analysis ; Phylogeography ; Plant Roots ; chemistry ; Plants, Medicinal ; chemistry ; Succinic Acid ; analysis ; Sucrose ; analysis ; Taurine ; analysis

In this study, we observed the alteration of choline signal intensity in hippocampus region of the depressive rat model induced by forced swimming test (FST). The purpose of this study was to evaluate the antidepressant efficacy in the depressive animal model using MR spectroscopy. Fourteen experimentally naive male Sprague-Dawley rats weighting 160~180 g were used as subjects. Drug injection group was exposed to the FST except for control group. The drugs were administered subcutaneously (SC) in a volume equivalent to 2 ml/kg. And three injections were administered 23, 5, and 1 h before beginning the given test. 1H MR spectra were obtained with use of a point resolved spectroscopy (PRESS) localization sequence performed according to the following parameters: repetition time, 2500 ms; echo time, 144 ms; 512 average; 2048 complex data points; voxel dimensions, 1.5x2.5x2.5 mm3; acquisition time, 25 min. There were no differences in NAA/Cr and Cho/Cr ratio between the right and the left hippocampus both normal control rats and antidepressant-injected rats. Also, no differences were observed in NAA/Cr and Cho/Cr ratio between the normal control rats and the antidepressant-injected rats both the right and the left hippocampus. In this study, we found the recovery of choline signals in the depressive animal model similar to normal control groups as injecting desipramine-HCl which was antidepressant causing anti-immobility effects. Thus, we demonstrated that MR spectroscopy was able to aid in evaluating the antidepressant effect of desipramine-HCl.
Animals ; Choline ; Hippocampus ; Humans ; Magnetic Resonance Spectroscopy ; Male ; Models, Animal ; Protons ; Rats ; Rats, Sprague-Dawley ; Spectrum Analysis ; Swimming

PURPOSE: The purpose of this study was to determine, using in vivo and in vitro 1H MRS (MR spectroscopy), the characteristic biochemical metabolites related with breast cancer, and to assess the clinical usefulness and limitations of this modality. MATERIALS AND METHODS: For in vivo 1H MRS, nine patients with breast cancer and two normal volunteers were examined on a 1.5 T MR imager equipped with facilities for spectroscopy. In order to localize the breast lesion, axial and sagittal T1-weighted images and fat-suppressed T2-weighted images were obtained just prior to MRS; MR spectra were acquired at TR=3000 msec and TE=144 msec. For in vitro 1H MRS, breast tumor and adja-cent normal tissue were extracted from 13 patients with breast cancer, and in two of these, both in vivo and in vitro 1H MRS were performed. All in vitro 1H MRS specimens were immediately immersed in liquid nitrogen, and then in a preparation of perchloric acid. For quantitative analysis of the MR spectra of cancerous and normal breast tissue, the paired t-test was used (p < 0.05). RESULTS: At1H MRS in vivo, choline and two lipids were identified at 3.21 ppm, and 1.33 ppm and 0.9 ppm, re-spectively. The distinction between cancerous and normal breast tissue was based on the higher level of choline (3.21 ppm) present in the former. At 1H MRS in vitro, on the other hand, mean and standard deviation (% standard deviation) for the various metabolites in cancerous and normal breast tissue were as follows: choline, 30.195 +/- 2.448(8.108) and 22.648 +/- 1.938(8.556); trimethylamine, 3.425 +/- 0.335(9.769) and 0.640 +/- 0.066(10.325); sarcosine, 3.425 +/- 0.335(9.769) and 0.640 +/- 0.099(15.394); lactate, 16.388 +/- 1.134(6.922) and 9.715 +/- 0.385(3.965); inositol, 1.970 +/- 0.282(14.334) and 3.859 +/- 0.502(13.020); and taurine, 6.614 +/- 0.556(8.412) and 10.748 +/- 1.206(11.222). High levels of choline (p=0.026), trimethylamine (p=0.001), sarco-sine (p=0.009), and lactate (p=0.009), and lower levels of inositol (p=0.006) and taurine (p=0.008) were char-acteristic findings in cancerous as compared with normal breast tissue, with significantly different results. CONCLUSION: 1H MRS both in vitro and in vivo showed that increased choline levels were present in cancerous breast tissue, but that normal tissue does not contain choline. The presence of choline could therefore be used as a marker for malignancy in breast lesions. Information provided by in vitro 1H MRS, together with the development of in vivo 1H MRS with high field strength and high resolution, may be very useful for the diagnosis of breast cancer.
Breast Neoplasms* ; Breast* ; Choline ; Diagnosis ; Hand ; Healthy Volunteers ; Humans* ; Inositol ; Lactic Acid ; Magnetic Resonance Spectroscopy* ; Nitrogen ; Sarcosine ; Spectrum Analysis ; Taurine

OBJECTIVEThis study examined the biochemical metabolism by proton magnetic resonance spectroscopy ('H-MRS) in order to explore the value of 'H-MRS in idiopathic epilepsy in children.

METHODSThirty-three children with idiopathic epilepsy (14 cases with history of febrile seizures and 19 cases without) and six normal controls experienced MRI of the skull and brain and single-voxel 'H-MRS examinations of the hippocampi-temporal lobe. The signal intensities of N-acetylaspartate (NAA), eatine+phosphocreatine (Cr), choline-containing compounds (Cho) and lactate (Lac) and the ratios of NAA/ (Cho+Cr) and Lac/Cr were compared between the patients and normal controls.

RESULTSMRI examination showed that only one child with epilepsy had myelin dysplasia. 'H-MRS examination showed that the ratio of NAA/ (Cho+Cr) in the epilepsy group was lower than that in the control group (0.64+/-0.07 vs 0.73+/-0.05; P<0.01). The epileptic children with history of febrile seizures had a more decreased ratio of NAA/ (Cho+Cr) compared with those without the history (0.61+/-0.07 vs 0.66+/-0.06; P<0.05). There were no significant differences in the ratio of Lac/Cr between the epilepsy and the control groups.

CONCLUSIONS'H-MRS may provide early information on brain injury sensitively and non-invasively in children with epilepsy. It may be used for diagnosis and prognosis evaluation of epilepsy.

Aspartic Acid ; analogs & derivatives ; analysis ; Child ; Child, Preschool ; Choline ; analysis ; Epilepsy ; diagnosis ; metabolism ; Female ; Humans ; Magnetic Resonance Imaging ; Magnetic Resonance Spectroscopy ; methods ; Male ; Phosphocreatine ; analysis ; Protons

OBJECTIVE: To find an objective method for estimation of postmortem interval (PMI) with single-voxel proton MR spectroscopy at different temperature. METHODS: Changes of metabolite peak area and peak area ratio of the N-acetylaspartate (Naa), choline (Cho) and total creatine (Cr) in the brain of 24 rabbit models were measured by 1H-MR spectroscopy (1H-MRS) at 0.5, 1, 2, 4, 6, 8, 12, 16 and 24 h, respectively after death. RESULTS: Naa and Cr decreased continuously with the extension of PMI, and the ratios of Naa/Cr and Cho/Cr also decreased continuously with the extension of PMI within 24 h. The quadratic polynomial regression equation is y=0.0019x2-0.803x+1.4498 (R2=0.962) (Equation 1) with the Naa/Cr used as an independent variable, while the quadratic polynomial regression equation is y=-0.0024x2+0.926x+1.1777 (R2=0.986) (Equation 2) with the Cho/Cr used as an independent variable. The average deviations were about 2.10-37.90 min and 1.69-40.87 min, respectively if the PMI was estimated by Equation 1 and Equation 2, respectively. CONCLUSION Our study indicates that there is a strong correlation between Naa/Cr, Cho/Cr and PMI, which may be used for estimation of PMI at different temperature.
Animals ; Aspartic Acid/analysis* ; Brain Chemistry ; Choline/analysis* ; Creatine/analysis* ; Forensic Pathology ; Magnetic Resonance Spectroscopy ; Postmortem Changes ; Rabbits ; Temperature ; Time Factors

PURPOSE: To determine the usefulness of in-vivo proton MR spectroscopy (MRS) with short TE for grading glial brain tumors. MATERIALS AND METHODS: For the purpose of tumor grading, 32 patients with pathologically confirmed glial tu-mors were examined by proton MRS. This and MRI were performed on a 1.5 T superconductive MR scanner. T2-weighted FSE images (TR/TE=4,000/100msec) were used to obtain anatomical reference images. The stim-ulated- echo acquisition mode (STEAM: TR/TE/MT=3000/30/13.7msec) was used to acquire MRS data from the localized single-voxel (2 x2 x2 cm 3 ) in both hemispheres. Residual water resonance in the spectra was re-moved using a CHESS pulse sequence. Prior to baseline correction, MRS raw-data, free induction decay sig-nals were zero-filled, apodized by an exponential function with 8Hz line-broadening, and fourier transformed. To normalize signal intensities of metabolites such as N-acetyl aspartate (NAA), total choline (Cho), myo-inosi-tol (mI), and lactate (Lac), the creatine(Cr) peak was used as a standard. RESULTS: The concentration ratios of Cho/Cr, mI/Cr, alpha-Glx, Lac, and NAA/Cr changed linearly according to tu-mor grade. Increased Cho, mI, alpha-Glx, and Lac levels were clearly seen in all grades. The most dramatic in-creases, observed in either Grade III or IV, were 78% and 228% for Cho(p<0.001), 106% and 61% for mI (p<0.001), 32% and 5% for alpha-Glx, and 727% and 450% for Lac (p<0.001), respectively. Increase of concen-tration ratio of Lac/Cr observed only in Grade III and Grade IV. The concentration ratios of NAA/Cr decreased gradually as tumor grade increased(p<0.001). CONCLUSION: The metabolic changes seen on proton MR spectroscopy using short TE might be useful for grad-ing glial brain tumors.
Aspartic Acid ; Brain Neoplasms ; Brain* ; Choline ; Fourier Analysis ; Humans ; Lactic Acid ; Magnetic Resonance Imaging ; Magnetic Resonance Spectroscopy* ; Neoplasm Grading ; Protons* ; Spectrum Analysis ; Water

PURPOSE: To introduce and demonstrate the advantages of the new hybrid two-dimensional (2D) proton spectroscopic imaging (Sl) over the single voxel spectroscopy (SVS) and conventional 2D Sl in the clinical application of spectroscopy for pediatric cerebral disease. MATERIALS AND METHODS: Eighty-one hybrid 2D proton spectroscopic imaging was performed in 79 children (36 normal infants and children, 10 with hypoxic-ischemic injury, 20 with toxic metabolic encephalopathy, seven with brain tumor, three with meningoencephalitis, one with neurofibromatosis, one with Sturge-Weber syndrome and one with lissencephaly) ranging in age from the third day of life to 15 years. In adult volunteers (n = 5), all three techniques including hybrid 2D proton Sl, SVS using PRESS sequence, and conventional 2D proton Sl were performed. Both hybrid 2D proton Sl and SVS using PRESS sequence were performed in clinical cases(n= 12). All measurements were peformed with a 1.5-T scanner using standard head quadrature coil. The 16 x 16 phase encoding steps were set on variable field of view (FOV) depending on the size of the brain. The hybrid volume of interest inside FOV was set as 75 x 75 x 15 mm3 or smaller to get rid of unwanted fat signal. Point-resolved spectroscopy (TR/TE = 1,500 msec/135 or 270 msec) was employed with standard chemical shift selective saturation (CHESS) pulses for water suppression. The acquisition time and spectral quality of hybrid 2D proton Sl were compared with those of SVS and conventional 2D proton Sl. RESULTS: The hybrid 2D proton Sl was successfully conducted upon all patients. The 2D spectral data acquisition time was less than 6 minutes, while the data acquisition time of SVS was 4.3 minutes. This was short enough for pediatric application. The spectra acquired with hybrid 2D proton Sl showed nearly the same sensitivity and spectral resolution with SVS. The spectral quality of hybrid 2D proton Sl was, on the other hand, far better than that of conventional 2D proton Sl. The other advantage of hybrid 2D proton Sl was that the extent of metabolic abnormalities could be evaluated through the characteristics of the relative levels of the three metabolites, i.e., N-acetylaspartate, choline, and creatine. CONCLUSION: The hybrid 2D proton Sl can be successfully employed for the evaluation of the metabolic abnormalities in the various pathologic conditions of pediatric brain without penalty in acquisition time and spectral quality when compared to SVS. The extent of metabolic abnormalities, which cannot be obtained with SVS technique, also can be evaluated with hybrid 2D proton Sl.
Adult ; Brain Diseases, Metabolic ; Brain Neoplasms ; Brain* ; Child ; Choline ; Creatine ; Hand ; Head ; Humans ; Infant ; Magnetic Resonance Spectroscopy ; Meningoencephalitis ; Neurofibromatoses ; Protons* ; Spectrum Analysis ; Sturge-Weber Syndrome ; Volunteers ; Water

PURPOSE: To investigate the feasibility of in vivo proton magnetic resonance spectroscopy (MRS) for evaluation of lung cancer. MATERIALS AND METHODS: This prospective study was approved by the institutional review board of our hospital and informed consent was obtained in all patients. Ten patients (7 men, 3 women; mean age, 64.4) with pathologicallyproven lung cancer (mean, 56.8 mm; range, 44-77 mm) were enrolled to 1.5 T MRS using a single-voxel respiration-triggered point-resolved spectroscopic sequence. Technical success rate and the reason of technical failure, if any, were investigated. RESULTS: Out of 10 lung cancers, analyzable MRS spectra were obtained in 8 tumors (technical success rate, 80%). Two MRS datasets were not able to be analyzed due to serious baseline distortion. Choline and lipid signals were detected as major metabolites in analyzable MRS spectra. CONCLUSION: In vivo proton MRS method using a single-voxel respiration-triggered point-resolved spectroscopic sequence is feasible in obtaining the MR spectra of lung cancer because these spectra were analyzable and high success rate was shown in our study although there was the limitation of small patient group.
Choline ; Ethics Committees, Research ; Humans ; Informed Consent ; Lung ; Lung Neoplasms ; Magnetic Resonance Spectroscopy ; Magnetics ; Magnets ; Male ; Prospective Studies ; Protons ; Spectrum Analysis