BACKGROUND Cognitive dysfunction is the main manifestation of central neuropathy.Although cognitive impairments tend to be overlooked in patients with diabetes mellitus(DM),there is a growing body of evidence linking ...BACKGROUND Cognitive dysfunction is the main manifestation of central neuropathy.Although cognitive impairments tend to be overlooked in patients with diabetes mellitus(DM),there is a growing body of evidence linking DM to cognitive dysfunction.Hyperglycemia is closely related to neurological abnormalities,while often disregarded in clinical practice.Changes in cerebral neurotransmitter levels are associated with a variety of neurological abnormalities and may be closely related to blood glucose control in patients with type 2 DM(T2DM).AIM To evaluate the concentrations of cerebral neurotransmitters in T2DM patients exhibiting different hemoglobin A1c(HbA1c)levels.METHODS A total of 130 T2DM patients were enrolled at the Department of Endocrinology of Shanghai East Hospital.The participants were divided into four groups according to their HbA1c levels using the interquartile method,namely Q1(<7.875%),Q2(7.875%-9.050%),Q3(9.050%-11.200%)and Q4(≥11.200%).Clinical data were collected and measured,including age,height,weight,neck/waist/hip circumferences,blood pressure,comorbidities,duration of DM,and biochemical indicators.Meanwhile,neurotransmitters in the left hippocampus and left brainstem area were detected by proton magnetic resonance spectroscopy.RESULTS The HbA1c level was significantly associated with urinary microalbumin(mALB),triglyceride,low-density lipoprotein cholesterol(LDL-C),homeostasis model assessment of insulin resistance(HOMA-IR),and beta cell function(HOMA-β),N-acetylaspartate/creatine(NAA/Cr),and NAA/choline(NAA/Cho).Spearman correlation analysis showed that mALB,LDL-C,HOMA-IR and NAA/Cr in the left brainstem area were positively correlated with the level of HbA1c(P<0.05),whereas HOMA-βwas negatively correlated with the HbA1c level(P<0.05).Ordered multiple logistic regression analysis showed that NAA/Cho[Odds ratio(OR):1.608,95%confidence interval(95%CI):1.004-2.578,P<0.05],LDL-C(OR:1.627,95%CI:1.119-2.370,P<0.05),and HOMA-IR(OR:1.107,95%CI:1.031-1.188,P<0.01)were independent predictors of poor glycemic control.CONCLUSION The cerebral neurotransmitter concentrations in the left brainstem area in patients with T2DM are closely related to glycemic control,which may be the basis for the changes in cognitive function in diabetic patients.展开更多
BACKGROUND Cases of depression among adolescents are gradually increasing.The study of the physiological basis of cognitive function from a biochemical perspective has therefore been garnering increasing attention.Dep...BACKGROUND Cases of depression among adolescents are gradually increasing.The study of the physiological basis of cognitive function from a biochemical perspective has therefore been garnering increasing attention.Depression has been hypothesized to be associated with the brain biochemical metabolism of the anterior cingulate gyrus,frontal lobe white matter,and the thalamus.AIM To explore the application of proton magnetic resonance spectroscopy(1H-MRS)in the metabolic alterations in the prefrontal white matter(PWM)and gray matter(GM)in adolescents with depression.METHODS 1H-MRS was performed for semi-quantitative analysis of the biochemical metabolites N-acetylaspartate(NAA),choline(Cho)complexes,creatine(Cr),and myoinositol(mI)in bilateral PWM,anterior cingulate GM,and thalami of 31 adolescent patients with depression(research group)and 35 healthy adolescents(control group),and the NAA/Cr,Cho/Cr,and mI/Cr ratios were calculated.Meanwhile,Hamilton Depression Scale(HAMD)and Wechsler Memory Scale were used to assess the degree of depression and memory function in all adolescents.The correlation of brain metabolite levels with scale scores was also analyzed.RESULTS The research group had markedly higher HAMD-24 scores and lower memory quotient(MQ)compared with the control group(P<0.05).Adolescents with depression were found to have lower bilateral PWM NAA/Cr and Cho/Cr ratios compared with healthy adolescents(P<0.05).The mI/Cr ratios were found to be similar in both groups(P>0.05).The bilateral anterior cingulate GM NAA/Cr,Cho/Cr,and mI/Cr also did not demonstrate marked differences(P>0.05).No statistical inter-group difference was determined in NAA/Cr of the bilateral thalami(P>0.05),while bilateral thalamic Cho/Cr and mI/Cr were reduced in teenagers with depression compared with healthy adolescents(P<0.05).A significant negative correlation was observed between the HAMD-24 scores in adolescents with depression with bilateral PWM NAA/Cr and Cho/Cr and were inversely linked to bilateral thalamic Cho/Cr and mI/Cr(P<0.05).In adolescents with depressions,MQ positively correlated with right PWH NAA/Cr,left PWH Cho/Cr,and bilateral thalamic Cho/Cr and mI/Cr.CONCLUSION PWM and thalamic metabolic abnormalities might influence teen depression,and the reduction in bilateral PWM NAA/Cr and Cho/Cr could be related to the neuropathology of adolescents with depression suffering from memory impairment.There exists a possibility of dysfunction of nerve cell membrane phospholipids in the thalami of adolescent patients with depression.展开更多
The present study analyzed changes in the biochemical metabolites N-acetyl aspartate, choline, and creatine in a simple concussion rabbit model following quiet rest, hyperbaric oxygen therapy, or interference stimulat...The present study analyzed changes in the biochemical metabolites N-acetyl aspartate, choline, and creatine in a simple concussion rabbit model following quiet rest, hyperbaric oxygen therapy, or interference stimulation through the use of hydrogen proton magnetic resonance spectroscopy detection. Experimental findings showed that brain N-acetyl aspartate and choline peak values significantly decreased, while creatine peak values significantly increased following simple concussion. Following treatments, N-acetyl aspartate and choline peaks returned to normal levels in the quiet rest and hyperbaric oxygen therapy groups, but no changes were observed in the interference stimulation group. Results demonstrated abnormal changes in the brain biochemical metabolism environment following simple concussion. Quiet rest was shown to play an important role in restoration of biochemical metabolism following simple concussion.展开更多
In order to investigate the application of proton magnetic resonance spectroscopy (ill-MRS) and computerized tomography (CT) in the quantitative diagnosis of nonalcoholic fatty liver disease (NAFLD) and evaluati...In order to investigate the application of proton magnetic resonance spectroscopy (ill-MRS) and computerized tomography (CT) in the quantitative diagnosis of nonalcoholic fatty liver disease (NAFLD) and evaluation of therapeutic effects, 22 patients with NAFLD were selected according to the Chinese Medical Association's (CMA) standard of the NAFLD in comparison with 20 healthy volunteers (as control group). Blood samples for biochemistry were collected. The severity of hepatosteatosis was evaluated by ^1H-MRS scan and CT scan of liver. The intrahepatic content of lipid (IHCL) and CT value ratio of liver to spleen were calculated. The patients in NAFLD group were treated with Ganzhixiao Capsule for 8 weeks. The changes in IHCL and CT value ratio of liver to spleen were observed before and after treatment. In NAFLD group serum ALT, TG, IHCL calculated by ^1HMRS were increased and CT value ratio of liver to spleen decreased significantly as compared with control group. After treatment for 8 weeks serum ALT, TG, IHCL were decreased significantly, while CT value ratio of liver to spleen increased significantly in NAFLD group. It was suggested that IHCL could be measured precisely by ^1HMRS. NAFLD was treated effectively by Ganzhixiao capsule.展开更多
The aim of this study was to investigate proton magnetic resonance spectroscopy metabolite values in the medial prefrontal cortex of individuals with euthymic bipolar disorder. The subjects consisted of 15 patients wi...The aim of this study was to investigate proton magnetic resonance spectroscopy metabolite values in the medial prefrontal cortex of individuals with euthymic bipolar disorder. The subjects consisted of 15 patients with euthymic bipolar disorder type I and 15 healthy controls. We performed proton magnetic resonance spectroscopy of the bilateral medial prefrontal cortex and measured levels of N-acetyl aspartate, choline and creatine. Levels of these three metabolites in the medial prefrontal cortex were found to be lower in patients with bipolar disorder compared with healthy controls. A positive correlation was found between illness duration and choline levels in the right medial prefrontal cortex. Our study suggests that during the euthymic period, there are abnormalities in cellular energy and membrane phospholipid metabolism in the medial prefrontal cortex, and that this may impair neuronal activity and integrity.展开更多
BACKGROUND: Proton magnetic resonance spectroscopy (IH-MRS) non-invasively detects changes in chemical substances in the brain, which reflects the pathological metabolism.OBJECTIVE: To investigate changes in N-ace...BACKGROUND: Proton magnetic resonance spectroscopy (IH-MRS) non-invasively detects changes in chemical substances in the brain, which reflects the pathological metabolism.OBJECTIVE: To investigate changes in N-acetyl-aspartate (NAA), choline (Cho), creatine (Cr), and myoinositol (MI) in the gray and white matter of cerebral prefrontal lobe and cerebellum of patients with differential degrees of post-stroke depression (PSD) using ^1H-MRS. DESIGN: A case control study. SETTING: The First Affiliated Hospital of the Dalian Medical University. PARTICIPANTS: A total of 38 patients with stroke (28 male and l0 female patients, aged 40 to 79 years) were selected from the Department of Neurology, 1st Affiliated Hospital, Dalian Medical University, from February to October in 2004. All subjects met the DSM-IV criteria for cerebrovascular disease and depression. The degree of depression was defined according to Hamilton criteria. 38 patients with PSD were divided into two groups according to the time after ischemia, 20 patients in the acute group with less than 10 days after ischemic attack (mild: 16 patients, moderate/severe: 4 patients) and 18 patients in the chronic group with more than l l days after ischemic attack (mild: 15 patients, moderate/severe: 3 patients). Seventeen healthy volunteers with matching age from 41 to 80 years were examined as a control group. The study was approved by the Medical Ethics Committee of the University Medical Center Utrecht, and each participant signed an informed consent form. METHODS: Spectra were acquired by multi-voxel point-resolved spectroscopy (PRESS) sequence with GE signal.5T MR/i, localized in prefrontal cerebral lobe and cerebellum. Values of NAA, Cho, MI, and Cr ere compared between different graded PSD patients and control subjects with one-way analysis of variance in software SPSS 11.5. MAIN OUTCOME MEASURES: Metabolite concentration in different brain regions of interest. Difference in metabolites between distinctly graded PSD patients and control subjects. Exclusion of age-effects on metabolites. RESULTS: Metabolite concentrations of different brain regions: A significant rise in the Cho/Cr ratio was detected in the acute and chronic group compared to the control group. The ratio change was more significant in the acute group (P 〈 0.05). There was no significant difference between these three groups for other metabolites detected by IH-MRS in the right frontal white matter, bilateral frontal grey matter, and cerebellum (P 〉 0.05). Comparison of metabolite levels among differently graded PSD patients and control subjects: a significant increase in the Cho/Cr ratio was detected in the left frontal white matter compared to the control group (P 〈 0.05). There was no significant difference in age between patients in the stroke groups and the control group (P 〉 0.05), and similarly, there was no significant correlation between age and absolute or relative values in the control group (P 〉 0.05). CONCLUSION: Abnormalities of frontal lobe in PSD were located in the white matter. There was early abnormality of metabolic substance in PSD.展开更多
AIM To assess the association between liver fat content(LFC) and weight status in young adults using proton magnetic resonance spectroscopy(1H MRS) technique.METHODSSeventy-eight healthy young adults, between 19-30 ye...AIM To assess the association between liver fat content(LFC) and weight status in young adults using proton magnetic resonance spectroscopy(1H MRS) technique.METHODSSeventy-eight healthy young adults, between 19-30 years of age participated in this study. This group was then separated into a control of 39 subjects and an overweight/obese group(OW/OB group) consisting of 39 subjects. Blood biochemical quantity and 1 H MRS was performed for LFC assessment.RESULTS LFC was found to be almost three times higher in OW/OB group when compared to the control group. A 48.7% incidence of non-alcoholic fatty liver disease in the OW/OB group was found. Blood biochemical measurements showed statistically higher low-density lipoproteins and triglyceride, lower highdensity lipoproteins, and increased glycosylated hemoglobin and fasting glucose in the OW/OB group. Body mass index was a significant independent predictor for LFC after adjusting for age and sex(multiple linear regression; β = 0.459, P <0.001).CONCLUSION Due to the prevalence of high LFC in the OW/OB group, it can be proposed that weight gain and obesity are sensitive indicators of high hepatic fat content.展开更多
Objective: To determine whether AQP4 expression is associated with lactate (Lac) and Nacetyl aspartate (NAA) and with apparent diffusion coefficient (ADC) abnormality after rat cerebral ischemia. Methods: The ...Objective: To determine whether AQP4 expression is associated with lactate (Lac) and Nacetyl aspartate (NAA) and with apparent diffusion coefficient (ADC) abnormality after rat cerebral ischemia. Methods: The time courses of ADC and lactate and NAA assessed by proton magnetic resonance spectroscopy (^1HMRS) were investigated at the time point of 6 h, and 1, 3, 7 d after rat cerebral ischernia induced by middle cerebral artery occlusion. Expression of AQP4 mRNA and protein were measured using RT-PCR and Western blot analysis respectively. Results: Significant reductions of NAA concentration and increases of lactate concentration were found after rat cerebral ischemia. The expressions of AQP4 mRNA t and protein were increased at 6 h, and reached the peak at 1-3 d, then began to decrease at 7 d after rat cerebral ischemia. The expression of AQP4 was significantly correlated with NAA (rRT = -0. 856, rw = -0. 927, P〈0.01), and with lactate (rw=0. 473, rRT=0. 413, P〈0.05), and with ADC values during the period of 1-7d after rat cerebralischemia (rw=0.984, rRT=0.925, P〈0.05). In addition, correlations between Lac and the ADC values(r=-0. 677, P〈0.05)and between NAA and ADC values during the period of 1-7 d after rat cerebralischemia (r=0.909, P(0.05) were also observed. Conclusion: The data suggest that AQP4 is involved in the transport of water when brain edema is formed and cell membrane integrity is lost.展开更多
Objective: To explore water soluble metabolite features of brain tumor specimens with HRMAS-^1HMRS and its potential clinical value. Methods: There were thirty cases of pathologically proven brain tumor, including 6...Objective: To explore water soluble metabolite features of brain tumor specimens with HRMAS-^1HMRS and its potential clinical value. Methods: There were thirty cases of pathologically proven brain tumor, including 6 Ⅰ-Ⅱ grade astrocytomas, 7 Ⅲ grade anaplastic astrocytomas, 10 IV grade glioblastomas and 7 meningiomas. Used Varian Company 600 MHz spectrometer with the Nano-probe for acquisition HRMASJHMRS, which was postprocessed with jMRUI 3.2 version software. These metabolic probability and their ratios to Cr were summed. Results: (1) HRMAS-^1HMRS could resolve NAA, PCr/Cr, GPC ± PCho ± Cho, Glu/GIn, Gly, Tau, Ala, Lac, ml and so on. All samples showed Lac, 6 samples showed unknown single peak at 3.72 ppm or 3.90 ppm. (2) The mean Cho/Cr of 6 Ⅰ-ⅡI grade astrocytomas was 2.42 ± 1.01 (P = 0.003, compared with glioblastoma). The mean Cho/Cr of 7 anaplastic astrocytomas was 3.48 ± 0.59 (P = 0.01, compared with glioblastoma). The Cho/Cr of 10 glioblastomas broadly ranged from 0.9 to 11.3 (mean 5.40 ± 1.23). From Ⅰ-Ⅱ grade astrocytoma to glioblastoma, Ala/Cr, Tau/Cr and Gly/Cr trends were increased; the mean Ala/Cr of glioma was 0.31 ± 0.13. (3) Meningiomas showed higher Ala and Cho. Their Cr was lower than that of gliomas. 4/7 cases had no NAA, 3/7 patients had lower NAA. Mean Cho/Cr was 3.56 ± 1.01, Ala/Cr was 0.53 ±0.28 (P = 0.006, compared with glioma). Conclusion: HRMAS-^1HMRS can show further details in vivo MRS, resolve in vivo spectroscopic metabolite of Cho compound and differentiate the extent of benign and malignant glioma. With the increase in the malignant degree of gliomas, Cho, ml, Ala, Tau and Gly will increase. HRMAS-^1HMRS is the only method of isotropic spectroscopy for pathological specimens.展开更多
Previous studies have found that methylmercury can damage hippocampal neurons and accord- ingly cause cognitive dysfunction. However, a non-invasive, safe and accurate detection method for detecting hippocampal injury...Previous studies have found that methylmercury can damage hippocampal neurons and accord- ingly cause cognitive dysfunction. However, a non-invasive, safe and accurate detection method for detecting hippocampal injury has yet to be developed. This study aimed to detect methylmercury-induced damage on hippocampal tissue using proton magnetic resonance spectroscopy. Rats were given a subcutaneous injection of 4 and 2 mg/kg methylmercury into the neck for 50 consecutive days. Water maze and pathology tests confirmed that cognitive function had been impaired and that the ultrastructure of hippocampal tissue was altered after injection. The results of proton magnetic resonance spectroscopy revealed that the nitrogen-acetyl aspartate/ creatine, choline complex/creatine and myoinositol/creatine ratio in rat hippocampal tissue were unchanged. Therefore, proton magnetic resonance spectroscopy can not be used to determine structural damage in the adult rat hippocampus caused by methylmercury chloride.展开更多
BACKGROUND: In localized brain proton magnetic resonance spectroscopy (^1H-MRS), metabolite levels are often expressed as ratios, rather than absolute concentrations. Frequently, the denominator is creatine, which ...BACKGROUND: In localized brain proton magnetic resonance spectroscopy (^1H-MRS), metabolite levels are often expressed as ratios, rather than absolute concentrations. Frequently, the denominator is creatine, which is assumed to be stable in normal, as well as many pathological, states. However, in vivo creatine levels do not remain constant. Therefore, absolute metabolite measurements, which provide the precise concentrations of certain chemical compounds, are superior to metabolite ratios for determining pathological and evolutional changes. OBJECTIVE: To investigate the feasibility of quantification analysis of brain metabolite changes caused by central analgesics nasal spray using the ^1H-MRS and linear combination model (LCModel) methods. DESIGN, TIME AND SETTING: This neuroimaging, observational, animal study was performed at the Laboratory of the Department of Medical Imaging, Second Affiliated Hospital, Medical College, Shantou University, China from July to December 2007. MATERIALS: Butorphanol tartrate nasal spray, as a mixed agonist-antagonist opioid analgesic, was purchased from Shanghai Hengrui Pharmacy, China. A General Electric Signa 1.5T System (General Electric Medical Systems, Milwaukee, WI, USA) and LCModel software (Stephen Provencher, Oakville, Ontario, Canada) were used in this study. METHODS: MRS images were acquired in ten healthy swine aged 2 weeks using single-voxel point-resolved spectroscopic sequence. A region of interest (2 cm × 2 cm × 2 cm) was placed in the image centers of maximum brain parenchyma. Repeated MRS scanning was performed 15-20 minutes after intranasal administration of 1 mg of butorphanol tartrate. Three settings of repetition time/echo time were selected before and after nasal spray administration 3 000 ms/30 ms,1 500 ms/30 ms, and 3 000 ms/50 ms. Metabolite concentrations were estimated by LCModel software. MAIN OUTCOME MEASURES: ^1H-MRS spectra was obtained using various repetition time/echo time settings. Concentrations of glutamate compounds (glutamate + glutamine), N-acetyl aspartate, and choline were detected in swine brain prior to and following nasal spray treatment. RESULTS: The glutamate compounds curve was consistent with original spectra, when a repetition time/echo time of 3 000 ms/30 ms was adopted. Concentrations of glutamate compounds, N-acetyl aspartate, and choline decreased following administration. The most significant reduction was observed in glutamate compound concentrations from (9.28 ± 0.54) mmol/kg to (7.28 ± 0.54) mmol/kg (P 〈 0.05). CONCLUSION: ^1H-MRS and LCModel software were effectively utilized to quantitatively analyze and measure brain metabolites. Glutamate compounds might be an important neurotransmitter in central analgesia.展开更多
Hepatic steatosis as the most prevalent liver disorder can either be related to alcoholic liver disease (ALD) or non-alcoholic fatty liver disease (NAFLD). In both conditions, hepatocytes excessively accumulate fatcon...Hepatic steatosis as the most prevalent liver disorder can either be related to alcoholic liver disease (ALD) or non-alcoholic fatty liver disease (NAFLD). In both conditions, hepatocytes excessively accumulate fatcontaining vacuoles within their cytoplasm, which is the key histological feature. In contrast to ALD, NAFLD is commonly associated with metabolic syndrome, obesity and insulin resistance. To determine increased liver fat content, liver biopsy is currently considered the gold standard. Besides the invasive technique, various other non-invasive techniques have been developed, such as ultrasound, computed tomography (CT), magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) based methods. Among these techniques, ultrasound and CT provide only qualitative information about hepatic steatosis, whereas MRS-or MRI-based methods are able to determine even small amounts of fat accurately. These non-invasive magnetic resonance techniques have already proven their great potential, especially in longitudinal and cross-sectional studies regarding various metabolic conditions and medical treatment regimens. In this review, the most common, non-invasive MRS/MRI techniques for assessment of intrahepatic lipid content are described with their inherent advantages and limitations.展开更多
Objective To investigate the value of in vivo proton magnetic resonance spectroscopy (MRS) in the assessment of hepatocelhilar carcinoma (HCC) and monitor its metabolic change shortly after transcatheter arterial ...Objective To investigate the value of in vivo proton magnetic resonance spectroscopy (MRS) in the assessment of hepatocelhilar carcinoma (HCC) and monitor its metabolic change shortly after transcatheter arterial chemoembolization (TACE). Mothoda In this prospective study, 28 consecutive patients with large HCC ( ≥3 cm in diameter) confirmed by fine needle aspiration biopsy were recruited. The ^1H MRS of all hepatic lesions and some uninvolved liver parenchyma were performed with 1.5T whole body MR scanner. Among them, 15 cases were evaluated again about one week after TACE. The main metabolites such as choline and lipid before and after interventional therapy were measured to assess the early response of the tumor. The technical success rate of IH MRS in liver was high (33/41, 80% ), closely related to breath motion, location of lesion, and size of voxeL In spectra, the choline compound peak of HCC elevated compared with uninvolved liver parenchyma. After TACE, both the amplitude and the area of choline resonance peak significantly descended ( choline-to-lipid ratios from 0.352±0. 080 to 0. 167±0. 030, P = 0. 026; from 0. 205±0. 060 to 0. 070±0. 020, P = 0. 042, respectively ) ; yet lipid resonance peak ascended. Conclusions In vivo tH MRS is technically feasible for the evaluation of large focal hepatic lesions, however, the reproducibility and stability are not as good as routine MR scan. IH MRS can monitor the early stage metabolic changes of HCC after TACE but limitation like quantification still exists.展开更多
Primary liver cancer is the fifth most common malignancy in men and the eighth in women worldwide. The liver is also the second most common site for metastatic spread of cancer. To assist in the diagnosis of these liv...Primary liver cancer is the fifth most common malignancy in men and the eighth in women worldwide. The liver is also the second most common site for metastatic spread of cancer. To assist in the diagnosis of these liver lesions non-invasive advanced imaging techniques are desirable. Magnetic resonance (MR) is commonly used to identify anatomical lesions, but it is a very versatile technique and also can provide specific information on tumor pathophysiology and metabolism, in particular with the application of MR spectroscopy (MRS). This may include data on the type, grade and stage of tumors, and thus assist in further management of the disease. The purpose of this review is to summarize and discuss the available literature on proton, phosphorus and carbon-13-MRS as performed on primary liver tumors and metastases, with human applications as the main perspective. Upcoming MRSapproaches with potential applications to liver tumors are also included. Since knowledge of some technical background is indispensable to understand the results, a basic introduction of MRS and some technical issues of MRS as applied to tumors and metastases in the liver are described as well. In vivo MR spectroscopy of tumors in a metabolically active organ such as the liver has been demonstrated to provide important information on tumor metabolism, but it also is challenging as compared to applications on some other tissues, in particular in humans, mostly because of its abdominal location where movement may be a disturbing factor.展开更多
AIM: To investigate the metabolic profiles of xenograft pancreatic cancer before and after radiotherapy by high-resolution magic angle spinning proton magnetic resonance spectroscopy (HRMAS 1H NMR) combined with princ...AIM: To investigate the metabolic profiles of xenograft pancreatic cancer before and after radiotherapy by high-resolution magic angle spinning proton magnetic resonance spectroscopy (HRMAS 1H NMR) combined with principal components analysis (PCA) and evaluate the radiotherapeutic effect. METHODS: The nude mouse xenograft model of human pancreatic cancer was established by injecting human pancreatic cancer cell SW1990 subcutaneously into the nude mice. When the tumors volume reached 800 mm3 , the mice received various radiation doses. Two weeks later, tumor tissue sections were prepared for running the NMR measurements. 1H NMR and PCA were used to determine the changes in the metabolic profiles of tumor tissues after radiotherapy. Metabolic profiles of normal pancreas, pancreatic tumor tissues, and radiationtreated pancreatic tumor tissues were compared. RESULTS: Compared with 1H NMR spectra of the normal nude mouse pancreas, the levels of choline, taurine, alanine, isoleucine, leucine, valine, lactate, and glutamic acid of the pancreatic cancer group were increased, whereas an opposite trend for phosphocholine, glycerophosphocholine, and betaine was observed. The ratio of phosphocholine to creatine, and glycerophosphocholine to creatine showed noticeable decrease in the pancreatic cancer group. After further evaluation of the tissue metabolic profile after treatment with three different radiation doses, no significant change in metabolites was observed in the 1H NMR spectra, while the inhibition of tumor growth was in proportion to the radiation doses. However, PCA results showed that the levels of choline and betaine were decreased with the increased radiation dose, and conversely, the level of acetic acid was dramatically increased. CONCLUSION: The combined methods were demonstrated to have the potential for allowing early diagnosis and assessment of pancreatic cancer response to radiotherapy.展开更多
1H magnetic resonance spectroscopy and diffusion weighted imaging features of the cerebellar vermis in 17 medulloblastoma patients were retrospectively analyzed, and 17 healthy volunteers were selected as controls. 1H...1H magnetic resonance spectroscopy and diffusion weighted imaging features of the cerebellar vermis in 17 medulloblastoma patients were retrospectively analyzed, and 17 healthy volunteers were selected as controls. 1H magnetic resonance spectroscopy showed that in all 17 medulloblastoma patients, N-acetyl aspartate and creatine peaks were significantly decreased, the choline peak was significantly increased, and there was evidence of a myo-inositol peak. Further, 11 patients showed a low taurine peak at 3.4 ppm, five patients showed a lipid peak at 0.9-1.3 ppm, and three patients showed a negative lactic acid peak at 1.33 ppm. Compared with the control group, the ratios of N-acetyl aspartate/choline and N-acetyl aspartate/creatine were significantly decreased, and the ratio of choline/creatine was increased, in medulloblastoma patients. Diffusion weighted imaging displayed hyperintensity and decreased apparent diffusion coefficient in medulloblastoma patients. These findings indicate that 1H magnetic resonance spectroscopy and diffusion weighted imaging are useful for qualitative diagnosis of medulloblastoma.展开更多
BACKGROUND Hepatic steatosis is a very common problem worldwide.AIM To assess the performance of two-and six-point Dixon magnetic resonance(MR)techniques in the detection,quantification and grading of hepatic steatosi...BACKGROUND Hepatic steatosis is a very common problem worldwide.AIM To assess the performance of two-and six-point Dixon magnetic resonance(MR)techniques in the detection,quantification and grading of hepatic steatosis.METHODS A single-center retrospective study was performed in 62 patients with suspected parenchymal liver disease.MR sequences included two-point Dixon,six-point Dixon,MR spectroscopy(MRS)and MR elastography.Fat fraction(FF)estimates on the Dixon techniques were compared to the MRS-proton density FF(PDFF).Statistical tests used included Pearson’s correlation and receiver operating characteristic.RESULTS FF estimates on the Dixon techniques showed excellent correlation(≥0.95)with MRS-PDFF,and excellent accuracy[area under the receiver operating characteristic(AUROC)≥0.95]in:(1)Detecting steatosis;and(2)Grading severe steatosis,(P<0.001).In iron overload,two-point Dixon was not evaluable due to confounding T2*effects.FF estimates on six-point Dixon vs MRS-PDFF showed a moderate correlation(0.82)in iron overload vs an excellent correlation(0.97)without iron overload,(P<0.03).The accuracy of six-point Dixon in grading mild steatosis improved(AUROC:0.59 to 0.99)when iron overload cases were excluded.The excellent correlation(>0.9)between the Dixon techniques vs MRSPDFF did not change in the presence of liver fibrosis(P<0.01).CONCLUSION Dixon techniques performed satisfactorily for the evaluation of hepatic steatosis but with exceptions.展开更多
BACKGROUND Proton magnetic resonance spectroscopy(~1H MRS) is a technique widely used for investigating metabolites in humans. Lipids are stored outside the muscle cell are called extramyocellular lipids(EMCL), and li...BACKGROUND Proton magnetic resonance spectroscopy(~1H MRS) is a technique widely used for investigating metabolites in humans. Lipids are stored outside the muscle cell are called extramyocellular lipids(EMCL), and lipids stored on the inside of muscle cells are called intramyocellular lipids(IMCL). The relationship between metabolic syndrome and IMCL has been extensively studied.AIM To determine the effects of muscle fiber orientations on muscle metabolites using ~1H MRS.METHODS Chicken muscles were used as the subject in this study. MRS spectra were performed on a 1.5 T Magnetic resonance imaging machine(1.5 Tesla Philips Achieva). A single voxel(8 mm × 8 mm × 20 mm) was placed on the chicken extensor iliotibialis lateralis muscle with the muscle fiber oriented at 0°, 30°, 60°,and 90° to the main magnetic field. ~1H MRS spectra were acquired using a pointresolved spectroscopy, TR = 2000 ms, TE = 30 ms, and NSA = 256. Metabolites of interest from each orientation to the main magnetic field were compared using Wilcoxon signed-rank test. Differences less than 0.05 were considered to be statistically significant with 95%CI.RESULTS The metabolite profiles were different for each orientation of muscle fibers to the main magnetic field. The orientation at 90° was the most different compared to other orientations. The quantity of IMCL and EMCL exhibited statistically significantly changes with impacts at 30°, 60°, and 90° when compared with muscles aligned at 0° to the main magnetic field. Statistical analysis showed statistically significant IMCL(CH_3), EMCL(CH_3), and IMCL(CH_2) at 30°, 60°, and 90°(P = 0.017, 0.018, and 0.018, respectively) and EMCL(CH_2) at 30° and 60°(P =0.017 and 0.042, respectively). EMCL(CH_2) at 90° was unable to be measured in this study. The muscle lipids quantified at 30°, 60°, and 90° tended to be lower when compared to 0°.CONCLUSION Careful positioning is one of the most important factors to consider when studying ~1H MRS metabolites in muscles to ensure reproducibility and uniformity of muscle metabolite spectra.展开更多
基金Supported by the Academic Leaders Training Program of Pudong Health Bureau of Shanghai,No.PWRd2023-03Clinical Research Fund of Shanghai Municipal Commission of Health,No.202040136+1 种基金National Natural Science Foundation of China,No.82070842Jiangxi Health Commission Science and Technology Plan Project,No.202212838 and No.202212852.
文摘BACKGROUND Cognitive dysfunction is the main manifestation of central neuropathy.Although cognitive impairments tend to be overlooked in patients with diabetes mellitus(DM),there is a growing body of evidence linking DM to cognitive dysfunction.Hyperglycemia is closely related to neurological abnormalities,while often disregarded in clinical practice.Changes in cerebral neurotransmitter levels are associated with a variety of neurological abnormalities and may be closely related to blood glucose control in patients with type 2 DM(T2DM).AIM To evaluate the concentrations of cerebral neurotransmitters in T2DM patients exhibiting different hemoglobin A1c(HbA1c)levels.METHODS A total of 130 T2DM patients were enrolled at the Department of Endocrinology of Shanghai East Hospital.The participants were divided into four groups according to their HbA1c levels using the interquartile method,namely Q1(<7.875%),Q2(7.875%-9.050%),Q3(9.050%-11.200%)and Q4(≥11.200%).Clinical data were collected and measured,including age,height,weight,neck/waist/hip circumferences,blood pressure,comorbidities,duration of DM,and biochemical indicators.Meanwhile,neurotransmitters in the left hippocampus and left brainstem area were detected by proton magnetic resonance spectroscopy.RESULTS The HbA1c level was significantly associated with urinary microalbumin(mALB),triglyceride,low-density lipoprotein cholesterol(LDL-C),homeostasis model assessment of insulin resistance(HOMA-IR),and beta cell function(HOMA-β),N-acetylaspartate/creatine(NAA/Cr),and NAA/choline(NAA/Cho).Spearman correlation analysis showed that mALB,LDL-C,HOMA-IR and NAA/Cr in the left brainstem area were positively correlated with the level of HbA1c(P<0.05),whereas HOMA-βwas negatively correlated with the HbA1c level(P<0.05).Ordered multiple logistic regression analysis showed that NAA/Cho[Odds ratio(OR):1.608,95%confidence interval(95%CI):1.004-2.578,P<0.05],LDL-C(OR:1.627,95%CI:1.119-2.370,P<0.05),and HOMA-IR(OR:1.107,95%CI:1.031-1.188,P<0.01)were independent predictors of poor glycemic control.CONCLUSION The cerebral neurotransmitter concentrations in the left brainstem area in patients with T2DM are closely related to glycemic control,which may be the basis for the changes in cognitive function in diabetic patients.
基金Supported by the General Scientific Research Project of Zhejiang Provincial Department of Education,No.Y202248840 and No.Y201942374。
文摘BACKGROUND Cases of depression among adolescents are gradually increasing.The study of the physiological basis of cognitive function from a biochemical perspective has therefore been garnering increasing attention.Depression has been hypothesized to be associated with the brain biochemical metabolism of the anterior cingulate gyrus,frontal lobe white matter,and the thalamus.AIM To explore the application of proton magnetic resonance spectroscopy(1H-MRS)in the metabolic alterations in the prefrontal white matter(PWM)and gray matter(GM)in adolescents with depression.METHODS 1H-MRS was performed for semi-quantitative analysis of the biochemical metabolites N-acetylaspartate(NAA),choline(Cho)complexes,creatine(Cr),and myoinositol(mI)in bilateral PWM,anterior cingulate GM,and thalami of 31 adolescent patients with depression(research group)and 35 healthy adolescents(control group),and the NAA/Cr,Cho/Cr,and mI/Cr ratios were calculated.Meanwhile,Hamilton Depression Scale(HAMD)and Wechsler Memory Scale were used to assess the degree of depression and memory function in all adolescents.The correlation of brain metabolite levels with scale scores was also analyzed.RESULTS The research group had markedly higher HAMD-24 scores and lower memory quotient(MQ)compared with the control group(P<0.05).Adolescents with depression were found to have lower bilateral PWM NAA/Cr and Cho/Cr ratios compared with healthy adolescents(P<0.05).The mI/Cr ratios were found to be similar in both groups(P>0.05).The bilateral anterior cingulate GM NAA/Cr,Cho/Cr,and mI/Cr also did not demonstrate marked differences(P>0.05).No statistical inter-group difference was determined in NAA/Cr of the bilateral thalami(P>0.05),while bilateral thalamic Cho/Cr and mI/Cr were reduced in teenagers with depression compared with healthy adolescents(P<0.05).A significant negative correlation was observed between the HAMD-24 scores in adolescents with depression with bilateral PWM NAA/Cr and Cho/Cr and were inversely linked to bilateral thalamic Cho/Cr and mI/Cr(P<0.05).In adolescents with depressions,MQ positively correlated with right PWH NAA/Cr,left PWH Cho/Cr,and bilateral thalamic Cho/Cr and mI/Cr.CONCLUSION PWM and thalamic metabolic abnormalities might influence teen depression,and the reduction in bilateral PWM NAA/Cr and Cho/Cr could be related to the neuropathology of adolescents with depression suffering from memory impairment.There exists a possibility of dysfunction of nerve cell membrane phospholipids in the thalami of adolescent patients with depression.
基金Military Medical Science and Technology Research During the Eleventh Five-Year Plan,No. 06MA96
文摘The present study analyzed changes in the biochemical metabolites N-acetyl aspartate, choline, and creatine in a simple concussion rabbit model following quiet rest, hyperbaric oxygen therapy, or interference stimulation through the use of hydrogen proton magnetic resonance spectroscopy detection. Experimental findings showed that brain N-acetyl aspartate and choline peak values significantly decreased, while creatine peak values significantly increased following simple concussion. Following treatments, N-acetyl aspartate and choline peaks returned to normal levels in the quiet rest and hyperbaric oxygen therapy groups, but no changes were observed in the interference stimulation group. Results demonstrated abnormal changes in the brain biochemical metabolism environment following simple concussion. Quiet rest was shown to play an important role in restoration of biochemical metabolism following simple concussion.
文摘In order to investigate the application of proton magnetic resonance spectroscopy (ill-MRS) and computerized tomography (CT) in the quantitative diagnosis of nonalcoholic fatty liver disease (NAFLD) and evaluation of therapeutic effects, 22 patients with NAFLD were selected according to the Chinese Medical Association's (CMA) standard of the NAFLD in comparison with 20 healthy volunteers (as control group). Blood samples for biochemistry were collected. The severity of hepatosteatosis was evaluated by ^1H-MRS scan and CT scan of liver. The intrahepatic content of lipid (IHCL) and CT value ratio of liver to spleen were calculated. The patients in NAFLD group were treated with Ganzhixiao Capsule for 8 weeks. The changes in IHCL and CT value ratio of liver to spleen were observed before and after treatment. In NAFLD group serum ALT, TG, IHCL calculated by ^1HMRS were increased and CT value ratio of liver to spleen decreased significantly as compared with control group. After treatment for 8 weeks serum ALT, TG, IHCL were decreased significantly, while CT value ratio of liver to spleen increased significantly in NAFLD group. It was suggested that IHCL could be measured precisely by ^1HMRS. NAFLD was treated effectively by Ganzhixiao capsule.
基金supported by Pamukkale University(Scientific Research Projects Coordination Unit)
文摘The aim of this study was to investigate proton magnetic resonance spectroscopy metabolite values in the medial prefrontal cortex of individuals with euthymic bipolar disorder. The subjects consisted of 15 patients with euthymic bipolar disorder type I and 15 healthy controls. We performed proton magnetic resonance spectroscopy of the bilateral medial prefrontal cortex and measured levels of N-acetyl aspartate, choline and creatine. Levels of these three metabolites in the medial prefrontal cortex were found to be lower in patients with bipolar disorder compared with healthy controls. A positive correlation was found between illness duration and choline levels in the right medial prefrontal cortex. Our study suggests that during the euthymic period, there are abnormalities in cellular energy and membrane phospholipid metabolism in the medial prefrontal cortex, and that this may impair neuronal activity and integrity.
文摘BACKGROUND: Proton magnetic resonance spectroscopy (IH-MRS) non-invasively detects changes in chemical substances in the brain, which reflects the pathological metabolism.OBJECTIVE: To investigate changes in N-acetyl-aspartate (NAA), choline (Cho), creatine (Cr), and myoinositol (MI) in the gray and white matter of cerebral prefrontal lobe and cerebellum of patients with differential degrees of post-stroke depression (PSD) using ^1H-MRS. DESIGN: A case control study. SETTING: The First Affiliated Hospital of the Dalian Medical University. PARTICIPANTS: A total of 38 patients with stroke (28 male and l0 female patients, aged 40 to 79 years) were selected from the Department of Neurology, 1st Affiliated Hospital, Dalian Medical University, from February to October in 2004. All subjects met the DSM-IV criteria for cerebrovascular disease and depression. The degree of depression was defined according to Hamilton criteria. 38 patients with PSD were divided into two groups according to the time after ischemia, 20 patients in the acute group with less than 10 days after ischemic attack (mild: 16 patients, moderate/severe: 4 patients) and 18 patients in the chronic group with more than l l days after ischemic attack (mild: 15 patients, moderate/severe: 3 patients). Seventeen healthy volunteers with matching age from 41 to 80 years were examined as a control group. The study was approved by the Medical Ethics Committee of the University Medical Center Utrecht, and each participant signed an informed consent form. METHODS: Spectra were acquired by multi-voxel point-resolved spectroscopy (PRESS) sequence with GE signal.5T MR/i, localized in prefrontal cerebral lobe and cerebellum. Values of NAA, Cho, MI, and Cr ere compared between different graded PSD patients and control subjects with one-way analysis of variance in software SPSS 11.5. MAIN OUTCOME MEASURES: Metabolite concentration in different brain regions of interest. Difference in metabolites between distinctly graded PSD patients and control subjects. Exclusion of age-effects on metabolites. RESULTS: Metabolite concentrations of different brain regions: A significant rise in the Cho/Cr ratio was detected in the acute and chronic group compared to the control group. The ratio change was more significant in the acute group (P 〈 0.05). There was no significant difference between these three groups for other metabolites detected by IH-MRS in the right frontal white matter, bilateral frontal grey matter, and cerebellum (P 〉 0.05). Comparison of metabolite levels among differently graded PSD patients and control subjects: a significant increase in the Cho/Cr ratio was detected in the left frontal white matter compared to the control group (P 〈 0.05). There was no significant difference in age between patients in the stroke groups and the control group (P 〉 0.05), and similarly, there was no significant correlation between age and absolute or relative values in the control group (P 〉 0.05). CONCLUSION: Abnormalities of frontal lobe in PSD were located in the white matter. There was early abnormality of metabolic substance in PSD.
基金Supported by Faculty of Associated Medical Sciences,Chiang Mai University,Chiang Mai,Thailand,No.6593(4)1180
文摘AIM To assess the association between liver fat content(LFC) and weight status in young adults using proton magnetic resonance spectroscopy(1H MRS) technique.METHODSSeventy-eight healthy young adults, between 19-30 years of age participated in this study. This group was then separated into a control of 39 subjects and an overweight/obese group(OW/OB group) consisting of 39 subjects. Blood biochemical quantity and 1 H MRS was performed for LFC assessment.RESULTS LFC was found to be almost three times higher in OW/OB group when compared to the control group. A 48.7% incidence of non-alcoholic fatty liver disease in the OW/OB group was found. Blood biochemical measurements showed statistically higher low-density lipoproteins and triglyceride, lower highdensity lipoproteins, and increased glycosylated hemoglobin and fasting glucose in the OW/OB group. Body mass index was a significant independent predictor for LFC after adjusting for age and sex(multiple linear regression; β = 0.459, P <0.001).CONCLUSION Due to the prevalence of high LFC in the OW/OB group, it can be proposed that weight gain and obesity are sensitive indicators of high hepatic fat content.
文摘Objective: To determine whether AQP4 expression is associated with lactate (Lac) and Nacetyl aspartate (NAA) and with apparent diffusion coefficient (ADC) abnormality after rat cerebral ischemia. Methods: The time courses of ADC and lactate and NAA assessed by proton magnetic resonance spectroscopy (^1HMRS) were investigated at the time point of 6 h, and 1, 3, 7 d after rat cerebral ischernia induced by middle cerebral artery occlusion. Expression of AQP4 mRNA and protein were measured using RT-PCR and Western blot analysis respectively. Results: Significant reductions of NAA concentration and increases of lactate concentration were found after rat cerebral ischemia. The expressions of AQP4 mRNA t and protein were increased at 6 h, and reached the peak at 1-3 d, then began to decrease at 7 d after rat cerebral ischemia. The expression of AQP4 was significantly correlated with NAA (rRT = -0. 856, rw = -0. 927, P〈0.01), and with lactate (rw=0. 473, rRT=0. 413, P〈0.05), and with ADC values during the period of 1-7d after rat cerebralischemia (rw=0.984, rRT=0.925, P〈0.05). In addition, correlations between Lac and the ADC values(r=-0. 677, P〈0.05)and between NAA and ADC values during the period of 1-7 d after rat cerebralischemia (r=0.909, P(0.05) were also observed. Conclusion: The data suggest that AQP4 is involved in the transport of water when brain edema is formed and cell membrane integrity is lost.
文摘Objective: To explore water soluble metabolite features of brain tumor specimens with HRMAS-^1HMRS and its potential clinical value. Methods: There were thirty cases of pathologically proven brain tumor, including 6 Ⅰ-Ⅱ grade astrocytomas, 7 Ⅲ grade anaplastic astrocytomas, 10 IV grade glioblastomas and 7 meningiomas. Used Varian Company 600 MHz spectrometer with the Nano-probe for acquisition HRMASJHMRS, which was postprocessed with jMRUI 3.2 version software. These metabolic probability and their ratios to Cr were summed. Results: (1) HRMAS-^1HMRS could resolve NAA, PCr/Cr, GPC ± PCho ± Cho, Glu/GIn, Gly, Tau, Ala, Lac, ml and so on. All samples showed Lac, 6 samples showed unknown single peak at 3.72 ppm or 3.90 ppm. (2) The mean Cho/Cr of 6 Ⅰ-ⅡI grade astrocytomas was 2.42 ± 1.01 (P = 0.003, compared with glioblastoma). The mean Cho/Cr of 7 anaplastic astrocytomas was 3.48 ± 0.59 (P = 0.01, compared with glioblastoma). The Cho/Cr of 10 glioblastomas broadly ranged from 0.9 to 11.3 (mean 5.40 ± 1.23). From Ⅰ-Ⅱ grade astrocytoma to glioblastoma, Ala/Cr, Tau/Cr and Gly/Cr trends were increased; the mean Ala/Cr of glioma was 0.31 ± 0.13. (3) Meningiomas showed higher Ala and Cho. Their Cr was lower than that of gliomas. 4/7 cases had no NAA, 3/7 patients had lower NAA. Mean Cho/Cr was 3.56 ± 1.01, Ala/Cr was 0.53 ±0.28 (P = 0.006, compared with glioma). Conclusion: HRMAS-^1HMRS can show further details in vivo MRS, resolve in vivo spectroscopic metabolite of Cho compound and differentiate the extent of benign and malignant glioma. With the increase in the malignant degree of gliomas, Cho, ml, Ala, Tau and Gly will increase. HRMAS-^1HMRS is the only method of isotropic spectroscopy for pathological specimens.
基金supported by the National Natural Science Foundation of China,No81060231,81160338Hubei Province Natural Science Foundation of China,No.2013CFB277
文摘Previous studies have found that methylmercury can damage hippocampal neurons and accord- ingly cause cognitive dysfunction. However, a non-invasive, safe and accurate detection method for detecting hippocampal injury has yet to be developed. This study aimed to detect methylmercury-induced damage on hippocampal tissue using proton magnetic resonance spectroscopy. Rats were given a subcutaneous injection of 4 and 2 mg/kg methylmercury into the neck for 50 consecutive days. Water maze and pathology tests confirmed that cognitive function had been impaired and that the ultrastructure of hippocampal tissue was altered after injection. The results of proton magnetic resonance spectroscopy revealed that the nitrogen-acetyl aspartate/ creatine, choline complex/creatine and myoinositol/creatine ratio in rat hippocampal tissue were unchanged. Therefore, proton magnetic resonance spectroscopy can not be used to determine structural damage in the adult rat hippocampus caused by methylmercury chloride.
基金the National Natural Science Foundation of China,No. 3047051530570480
文摘BACKGROUND: In localized brain proton magnetic resonance spectroscopy (^1H-MRS), metabolite levels are often expressed as ratios, rather than absolute concentrations. Frequently, the denominator is creatine, which is assumed to be stable in normal, as well as many pathological, states. However, in vivo creatine levels do not remain constant. Therefore, absolute metabolite measurements, which provide the precise concentrations of certain chemical compounds, are superior to metabolite ratios for determining pathological and evolutional changes. OBJECTIVE: To investigate the feasibility of quantification analysis of brain metabolite changes caused by central analgesics nasal spray using the ^1H-MRS and linear combination model (LCModel) methods. DESIGN, TIME AND SETTING: This neuroimaging, observational, animal study was performed at the Laboratory of the Department of Medical Imaging, Second Affiliated Hospital, Medical College, Shantou University, China from July to December 2007. MATERIALS: Butorphanol tartrate nasal spray, as a mixed agonist-antagonist opioid analgesic, was purchased from Shanghai Hengrui Pharmacy, China. A General Electric Signa 1.5T System (General Electric Medical Systems, Milwaukee, WI, USA) and LCModel software (Stephen Provencher, Oakville, Ontario, Canada) were used in this study. METHODS: MRS images were acquired in ten healthy swine aged 2 weeks using single-voxel point-resolved spectroscopic sequence. A region of interest (2 cm × 2 cm × 2 cm) was placed in the image centers of maximum brain parenchyma. Repeated MRS scanning was performed 15-20 minutes after intranasal administration of 1 mg of butorphanol tartrate. Three settings of repetition time/echo time were selected before and after nasal spray administration 3 000 ms/30 ms,1 500 ms/30 ms, and 3 000 ms/50 ms. Metabolite concentrations were estimated by LCModel software. MAIN OUTCOME MEASURES: ^1H-MRS spectra was obtained using various repetition time/echo time settings. Concentrations of glutamate compounds (glutamate + glutamine), N-acetyl aspartate, and choline were detected in swine brain prior to and following nasal spray treatment. RESULTS: The glutamate compounds curve was consistent with original spectra, when a repetition time/echo time of 3 000 ms/30 ms was adopted. Concentrations of glutamate compounds, N-acetyl aspartate, and choline decreased following administration. The most significant reduction was observed in glutamate compound concentrations from (9.28 ± 0.54) mmol/kg to (7.28 ± 0.54) mmol/kg (P 〈 0.05). CONCLUSION: ^1H-MRS and LCModel software were effectively utilized to quantitatively analyze and measure brain metabolites. Glutamate compounds might be an important neurotransmitter in central analgesia.
文摘Hepatic steatosis as the most prevalent liver disorder can either be related to alcoholic liver disease (ALD) or non-alcoholic fatty liver disease (NAFLD). In both conditions, hepatocytes excessively accumulate fatcontaining vacuoles within their cytoplasm, which is the key histological feature. In contrast to ALD, NAFLD is commonly associated with metabolic syndrome, obesity and insulin resistance. To determine increased liver fat content, liver biopsy is currently considered the gold standard. Besides the invasive technique, various other non-invasive techniques have been developed, such as ultrasound, computed tomography (CT), magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) based methods. Among these techniques, ultrasound and CT provide only qualitative information about hepatic steatosis, whereas MRS-or MRI-based methods are able to determine even small amounts of fat accurately. These non-invasive magnetic resonance techniques have already proven their great potential, especially in longitudinal and cross-sectional studies regarding various metabolic conditions and medical treatment regimens. In this review, the most common, non-invasive MRS/MRI techniques for assessment of intrahepatic lipid content are described with their inherent advantages and limitations.
基金Supported by National Natural Sciences Foundation of China(30470503)
文摘Objective To investigate the value of in vivo proton magnetic resonance spectroscopy (MRS) in the assessment of hepatocelhilar carcinoma (HCC) and monitor its metabolic change shortly after transcatheter arterial chemoembolization (TACE). Mothoda In this prospective study, 28 consecutive patients with large HCC ( ≥3 cm in diameter) confirmed by fine needle aspiration biopsy were recruited. The ^1H MRS of all hepatic lesions and some uninvolved liver parenchyma were performed with 1.5T whole body MR scanner. Among them, 15 cases were evaluated again about one week after TACE. The main metabolites such as choline and lipid before and after interventional therapy were measured to assess the early response of the tumor. The technical success rate of IH MRS in liver was high (33/41, 80% ), closely related to breath motion, location of lesion, and size of voxeL In spectra, the choline compound peak of HCC elevated compared with uninvolved liver parenchyma. After TACE, both the amplitude and the area of choline resonance peak significantly descended ( choline-to-lipid ratios from 0.352±0. 080 to 0. 167±0. 030, P = 0. 026; from 0. 205±0. 060 to 0. 070±0. 020, P = 0. 042, respectively ) ; yet lipid resonance peak ascended. Conclusions In vivo tH MRS is technically feasible for the evaluation of large focal hepatic lesions, however, the reproducibility and stability are not as good as routine MR scan. IH MRS can monitor the early stage metabolic changes of HCC after TACE but limitation like quantification still exists.
基金Supported by A grant from the Dutch Cancer Society (KWF Kankerbestrijding), No. KUN 2008-4098
文摘Primary liver cancer is the fifth most common malignancy in men and the eighth in women worldwide. The liver is also the second most common site for metastatic spread of cancer. To assist in the diagnosis of these liver lesions non-invasive advanced imaging techniques are desirable. Magnetic resonance (MR) is commonly used to identify anatomical lesions, but it is a very versatile technique and also can provide specific information on tumor pathophysiology and metabolism, in particular with the application of MR spectroscopy (MRS). This may include data on the type, grade and stage of tumors, and thus assist in further management of the disease. The purpose of this review is to summarize and discuss the available literature on proton, phosphorus and carbon-13-MRS as performed on primary liver tumors and metastases, with human applications as the main perspective. Upcoming MRSapproaches with potential applications to liver tumors are also included. Since knowledge of some technical background is indispensable to understand the results, a basic introduction of MRS and some technical issues of MRS as applied to tumors and metastases in the liver are described as well. In vivo MR spectroscopy of tumors in a metabolically active organ such as the liver has been demonstrated to provide important information on tumor metabolism, but it also is challenging as compared to applications on some other tissues, in particular in humans, mostly because of its abdominal location where movement may be a disturbing factor.
基金Supported by The Medical Imageology Special Purpose Foundation of Cancer Hospital/Cancer Institute Fudan University, No.YX200802
文摘AIM: To investigate the metabolic profiles of xenograft pancreatic cancer before and after radiotherapy by high-resolution magic angle spinning proton magnetic resonance spectroscopy (HRMAS 1H NMR) combined with principal components analysis (PCA) and evaluate the radiotherapeutic effect. METHODS: The nude mouse xenograft model of human pancreatic cancer was established by injecting human pancreatic cancer cell SW1990 subcutaneously into the nude mice. When the tumors volume reached 800 mm3 , the mice received various radiation doses. Two weeks later, tumor tissue sections were prepared for running the NMR measurements. 1H NMR and PCA were used to determine the changes in the metabolic profiles of tumor tissues after radiotherapy. Metabolic profiles of normal pancreas, pancreatic tumor tissues, and radiationtreated pancreatic tumor tissues were compared. RESULTS: Compared with 1H NMR spectra of the normal nude mouse pancreas, the levels of choline, taurine, alanine, isoleucine, leucine, valine, lactate, and glutamic acid of the pancreatic cancer group were increased, whereas an opposite trend for phosphocholine, glycerophosphocholine, and betaine was observed. The ratio of phosphocholine to creatine, and glycerophosphocholine to creatine showed noticeable decrease in the pancreatic cancer group. After further evaluation of the tissue metabolic profile after treatment with three different radiation doses, no significant change in metabolites was observed in the 1H NMR spectra, while the inhibition of tumor growth was in proportion to the radiation doses. However, PCA results showed that the levels of choline and betaine were decreased with the increased radiation dose, and conversely, the level of acetic acid was dramatically increased. CONCLUSION: The combined methods were demonstrated to have the potential for allowing early diagnosis and assessment of pancreatic cancer response to radiotherapy.
基金supported by the National Natural Science Foundation of China, No. 81171315the Fundamental Research Funds of the Central Universities, No. 303275894the Natural Science Foundation of Hubei Province, No.2009CDA071
文摘1H magnetic resonance spectroscopy and diffusion weighted imaging features of the cerebellar vermis in 17 medulloblastoma patients were retrospectively analyzed, and 17 healthy volunteers were selected as controls. 1H magnetic resonance spectroscopy showed that in all 17 medulloblastoma patients, N-acetyl aspartate and creatine peaks were significantly decreased, the choline peak was significantly increased, and there was evidence of a myo-inositol peak. Further, 11 patients showed a low taurine peak at 3.4 ppm, five patients showed a lipid peak at 0.9-1.3 ppm, and three patients showed a negative lactic acid peak at 1.33 ppm. Compared with the control group, the ratios of N-acetyl aspartate/choline and N-acetyl aspartate/creatine were significantly decreased, and the ratio of choline/creatine was increased, in medulloblastoma patients. Diffusion weighted imaging displayed hyperintensity and decreased apparent diffusion coefficient in medulloblastoma patients. These findings indicate that 1H magnetic resonance spectroscopy and diffusion weighted imaging are useful for qualitative diagnosis of medulloblastoma.
文摘BACKGROUND Hepatic steatosis is a very common problem worldwide.AIM To assess the performance of two-and six-point Dixon magnetic resonance(MR)techniques in the detection,quantification and grading of hepatic steatosis.METHODS A single-center retrospective study was performed in 62 patients with suspected parenchymal liver disease.MR sequences included two-point Dixon,six-point Dixon,MR spectroscopy(MRS)and MR elastography.Fat fraction(FF)estimates on the Dixon techniques were compared to the MRS-proton density FF(PDFF).Statistical tests used included Pearson’s correlation and receiver operating characteristic.RESULTS FF estimates on the Dixon techniques showed excellent correlation(≥0.95)with MRS-PDFF,and excellent accuracy[area under the receiver operating characteristic(AUROC)≥0.95]in:(1)Detecting steatosis;and(2)Grading severe steatosis,(P<0.001).In iron overload,two-point Dixon was not evaluable due to confounding T2*effects.FF estimates on six-point Dixon vs MRS-PDFF showed a moderate correlation(0.82)in iron overload vs an excellent correlation(0.97)without iron overload,(P<0.03).The accuracy of six-point Dixon in grading mild steatosis improved(AUROC:0.59 to 0.99)when iron overload cases were excluded.The excellent correlation(>0.9)between the Dixon techniques vs MRSPDFF did not change in the presence of liver fibrosis(P<0.01).CONCLUSION Dixon techniques performed satisfactorily for the evaluation of hepatic steatosis but with exceptions.
基金Supported by Department of Radiologic Technology,Faculty of Associated Medical Sciences,Chiang Mai University,Thailand
文摘BACKGROUND Proton magnetic resonance spectroscopy(~1H MRS) is a technique widely used for investigating metabolites in humans. Lipids are stored outside the muscle cell are called extramyocellular lipids(EMCL), and lipids stored on the inside of muscle cells are called intramyocellular lipids(IMCL). The relationship between metabolic syndrome and IMCL has been extensively studied.AIM To determine the effects of muscle fiber orientations on muscle metabolites using ~1H MRS.METHODS Chicken muscles were used as the subject in this study. MRS spectra were performed on a 1.5 T Magnetic resonance imaging machine(1.5 Tesla Philips Achieva). A single voxel(8 mm × 8 mm × 20 mm) was placed on the chicken extensor iliotibialis lateralis muscle with the muscle fiber oriented at 0°, 30°, 60°,and 90° to the main magnetic field. ~1H MRS spectra were acquired using a pointresolved spectroscopy, TR = 2000 ms, TE = 30 ms, and NSA = 256. Metabolites of interest from each orientation to the main magnetic field were compared using Wilcoxon signed-rank test. Differences less than 0.05 were considered to be statistically significant with 95%CI.RESULTS The metabolite profiles were different for each orientation of muscle fibers to the main magnetic field. The orientation at 90° was the most different compared to other orientations. The quantity of IMCL and EMCL exhibited statistically significantly changes with impacts at 30°, 60°, and 90° when compared with muscles aligned at 0° to the main magnetic field. Statistical analysis showed statistically significant IMCL(CH_3), EMCL(CH_3), and IMCL(CH_2) at 30°, 60°, and 90°(P = 0.017, 0.018, and 0.018, respectively) and EMCL(CH_2) at 30° and 60°(P =0.017 and 0.042, respectively). EMCL(CH_2) at 90° was unable to be measured in this study. The muscle lipids quantified at 30°, 60°, and 90° tended to be lower when compared to 0°.CONCLUSION Careful positioning is one of the most important factors to consider when studying ~1H MRS metabolites in muscles to ensure reproducibility and uniformity of muscle metabolite spectra.