ABSTRACT
Objective:To noninvasively evaluate the clinical value of early renal function changes in patients with type 2 diabetes mellitus (T2DM) using blood oxygenation level dependent (BOLD) and arterial spin labeling (ASL) MRI.Methods:A total of 63 T2DM patients from Tianjin First Central Hospital from September 2019 to May 2022 were prospectively collected, 30 healthy volunteers (control group) were collected during the same period. According to albumin creatinine ratio (ACR), patients with T2DM were divided into normal albuminuria (NAU, ACR<30 mg/g) group and microalbuminuria (MAU, 30 mg/g≤ACR≤300 mg/g) group, there were 35 and 28 cases respectively. All subjects underwent abdominal BOLD and ASL scans. The values of renal cortical and medullary apparent relaxation rate (R 2*) and renal cortical renal blood flow (RBF) were measured. One-way ANOVA was used to compare the differences in R 2* and RBF among the three groups. Receiver operating characteristic curve was used to analyze relevant parameters to identify the diagnostic effectiveness of each group, and area under the curve (AUC) was compared by Z-test. Results:There were significant differences in renal medullary R 2* and renal cortical RBF among the control group, NAU group and MAU group ( F=45.83, 34.15, P<0.001). There was no significant difference in renal cortical R 2* ( F=2.98, P=0.056). In differentiating the control group from the NAU group, the AUC of renal medullary R 2*, renal cortical RBF and their combined parameters were 0.921 (95%CI 0.827-0.973), 0.704 (95%CI 0.578-0.811), 0.964 (95%CI 0.885-0.994), respectively. The AUC of combined parameters was significantly different from renal cortical RBF ( Z=4.07, P<0.001), but not from renal medullary R 2* ( Z=1.57, P=0.117). In differentiating the NAU from the MAU group, the AUC were 0.898 (95%CI 0.796-0.960), 0.919 (95%CI 0.823-0.973), 0.985 (95%CI 0.881-0.994), respectively. The AUC of combined parameters was significantly different from renal medullary R 2* and renal cortical RBF ( Z=2.39, P=0.017; Z=2.20, P=0.028). Conclusions:The changes of renal oxygenation level and blood flow in early stage of T2DM patients can be evaluated noninvasively and quantitatively using BOLD and ASL. Renal medullary R 2* combined with renal cortex RBF shows better diagnostic efficacy for early renal function changes in diabetes than each single index.
ABSTRACT
Objective: To active simulation and imaging of human brain blood oxygenation level dependent (BOLD) signal, taken which as gold standard and standard signal to detect the quality and detection rate of brain MRI functional magnetic resonance imaging (fMRI) based on the changes of gray amplitude of BOLD signals during imaging. Methods: A new excitation circuit that could simulate the BOLD of the human brain was used to achieve the stable rectangular wave output of different current amplitude, different frequency and different space ratio, and the BOLD signal of the human brain in the time domain was simulated. Results: Stable rectangular wave input and consistent detection rate were obtained with 3 different MR devices with different field strength. Conclusion: The same device has similar detection rate for the design of the same stimulus model, which can be used as the reference standard of the known and determined signal to analyze the detection rate and consistency of BOLD signal.
ABSTRACT
Objective: To explore the impact of non-ionic dimeric isotonic iodine contrast agent on rabbit kidneys using intravoxel incoherent motion (IVIM)-DWI and blood oxygen level-dependent (BOLD) imaging. Methods: Totally 25 male New Zealand rabbits were randomly equally divided into 5 groups (each n=5). IVIM-DWI and BOLD scanning and blood collection were performed in four experimental groups (1, 24, 48, 72 h group) 1, 24, 48,72 h after injection of iodixanol, respectively, also in base-line group after injection of equal amount of saline. The rabbits were killed immediately after MRI,and the kidneys were taken for histopathological analysis. Results: Compared with base-line group, both cortex and medulla of kidneys showed decreased ADC, D and f values and the lowest D* value, as well as increased R2* in 1 h group. The lowest ADC, D and f values, the highest R2* and increased D* value of both cortex and medulla were observed in 24 h group. In 72 h group, R2* value of both cortex and medulla were still lower than baseline (all P<0.05), and D* value basically returned to baseline, while f and D values of medulla were still statistically different with respect to baseline (all P<0.05). Meanwhile, different degrees of glomerular and tubular damage were observed in the pathological sections. The serum creatinine and blood urea nitrogen in 48 h group and 72 h group were higher than those in base-line group (all P<0.05). The expression of hypoxia inducible factor-1α and heme oxygenase-1 increased in 1 h group and up to peak in 24 h group. Conclusion: Combining IVIM-DWI with BOLD can effectively evaluate rabbit renal pathophysiologic changes associated with contrast-induced acute kidney injury.
ABSTRACT
Objective: To evaluate the impact of iodinated contrast media on renal oxygenation content in rabbits with diabetic nephropathy using BOLD-MRI. Methods: Totally 32 rabbits with diabetic nephropathy (experimental group) were randomly divided into 4 groups (each n=8) and received iodinated contrast media with different concentration (200, 240, 300, 350 mgI/ml, named 200 subgroup, 240 subgroup, 300 subgroup and 350 subgroup, respectively). Rabbits in control group (8 normal rabbits) received normal saline (NS). BOLD-MRI was performed at 1, 24, 48 and 72 h after injection, and R2* value of renal cortex, extramedulla and intramedulla of the rabbits were measured and compared among different groups and different time points. Results: One hour after administration of iodinated contrast media, R2* value of the renal cortex, extramedulla and intramedulla increased in experimental group, reaching their peak value at 24 h and then declined. Significant differences of R2* value were found among 4 subgroups at all time points after injection (all P<0.001), and with the increase of iodine concentration, R2* value increased, with the highest R2* value observed in 350 subgroup. In experimental group, R2* value of the extramedulla was higher than the cortex and intramedulla 24 h after injection in 350 subgroup (both P<0.05). Conclusion: Iodinated contrast media can significantly affect the oxygen content of renal extramedulla in diabetic nephropathy rabbits, and the changes may have certain rules. BOLD-MRI can provide auxiliary information for rational clinical application of contrast agent and monitoring renal function.
ABSTRACT
OBJECTIVE@#To evaluate the changes in renal oxygenation in rats with acute aristolochic acid nephropathy using blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) at 7.0T.@*METHODS@#Wistar rats were randomly divided into AAN group (=18) and control group (=6) for intraperitoneal injections of AAI at 40 mg/kg and PEG400, respectively, on a daily basis for 6 consecutive days. All the control rats and 6 rats from AAN group underwent BOLD MRI scan before and at 2, 4, and 6 days after the initial injection for measuring renal cortical and medullary R2 values. At each of the 4 time points, 3 rats in AAN group were sacrificed for histological evaluation; the control rats were examined at 6 days after the initial injection.@*RESULTS@#The cortical and medullary R2 values of the rats in AAN group on days 4 and 6 were significantly higher than those in the control group ( < 0.05). In AAN group, the cortical R2 values showed no obvious changes on day 2 as compared with the baseline values, but increased significantly on day 4 ( < 0.05) and day 6 ( < 0.01); the medullary R2 values increased progressively and were significantly higher than the baseline values on day 4 ( < 0.01) and day 6 ( < 0.01). In the control group, no significant changes were detected in either cortical or medullary R2 values throughout the experiment.@*CONCLUSIONS@#BOLD MRI allows non-invasive measurement of renal oxygenation levels in rats with AAN. The increase of renal cortical and medullary R2 values, and particularly the latter, indicates a lowered renal oxygenation level, which provides potentially useful information for clinical decisions.
Subject(s)
Animals , Rats , Aristolochic Acids , Kidney , Kidney Diseases , Metabolism , Magnetic Resonance Imaging , Oxygen , Random Allocation , Rats, WistarABSTRACT
Clinical imaging research of spinal cord has urgent realistic needs, and faces enormous challenges and opportunities. Among them, functional magnetic resonance imaging is a hot and difficult topic because of the particularity of spinal cord structure and related technical bottlenecks. In recent years, advances in magnetic resonance hardware and software technology have led to breakthroughs in the technical nodes, which have opened up a new prospect for the clinical application of spinal cord imaging. The recent progress in functional magnetic resonance imaging of spinal cord is reviewed in this article.
ABSTRACT
Objective To establish the methodology of combining BOLD and 1H-MRS for investigating correlation between the deactivation in medial prefrontal cortex (MPFC) and gamma-aminobutyric acid (GABA) concentration by acupuncture at LI4 (Point Hegu),and to optimize the experimental technique and procedure.Methods Twenty healthy adult volunteers were enrolled.During fMRI-BOLD scanning,each subject received acupuncture at right LI4 (Point Hegu).MRS scanning was based on MEGA-PRESS sequence,and ROIs were located at bilateral MPFC.The task BOLD fMRI was block design,including 3 stimulations (30 s) with 2 intervals (2 min).Then MRS scanning was performed before and after BOLD.The quantitative values of the BOLD positive and negative activations (Pm) and GABA concentrations were calculated.Results All 20 subjects completed BOLD fMRI scanning,and met the postprocessing requirements.MRS images of 9 subjects with good image quality were included in analysis.Among all 20 subjects,positive activation (Pm=1.17± 0.16) was observed in 9,while negative activation (Pm =-1.31 ± 0.17) was observed in 11 subjects.The GABA average values before and after the acupuncture were (19.93 ±1.04) nmol/L and (20.04±0.81)nmol/L,respectively,and the average amplitude between post-and pre-acupuncture was (0.11 ± 1.60)nmol/L.Conclusion The success rate of this method for quantitative study of brain function established multimodal-functional (BOLD-fMRI and MRS) was acceptable,and the multimodal brain function changes as well as the quantitative values were observed in the brain region during acupuncture.Combined BOLD and MRS quantitative method is feasible for testing acupuncture response in the brain.
ABSTRACT
PURPOSE: To describe technical methods for functional magnetic resonance imaging (fMRI) study with arterial spin labeling (ASL) compared to blood oxygenation level-dependent (BOLD) technique and discuss the potential of ASL for research and clinical practice. MATERIALS AND METHODS: Task-based (n = 1) and resting-state fMRI (rs-fMRI) (n = 20) were performed using ASL and BOLD techniques. Results of both techniques were compared. RESULTS: For task-based fMRI with finger-tapping, the primary motor cortex of the contralateral frontal lobe and the ipsilateral cerebellum were activated by both BOLD and ASL fMRI. For rs-fMRI of sensorimotor network, functional connectivity showed similar results between BOLD and ASL. CONCLUSION: ASL technique has potential application in clinical and research fields because all brain perfusion imaging, CBF measurement, and rs-fMRI study can be performed in a single acquisition.
Subject(s)
Brain , Cerebellum , Frontal Lobe , Magnetic Resonance Imaging , Motor Cortex , Oxygen , Perfusion ImagingABSTRACT
PURPOSE: To describe technical methods for functional magnetic resonance imaging (fMRI) study with arterial spin labeling (ASL) compared to blood oxygenation level-dependent (BOLD) technique and discuss the potential of ASL for research and clinical practice. MATERIALS AND METHODS: Task-based (n = 1) and resting-state fMRI (rs-fMRI) (n = 20) were performed using ASL and BOLD techniques. Results of both techniques were compared. RESULTS: For task-based fMRI with finger-tapping, the primary motor cortex of the contralateral frontal lobe and the ipsilateral cerebellum were activated by both BOLD and ASL fMRI. For rs-fMRI of sensorimotor network, functional connectivity showed similar results between BOLD and ASL. CONCLUSION: ASL technique has potential application in clinical and research fields because all brain perfusion imaging, CBF measurement, and rs-fMRI study can be performed in a single acquisition.
Subject(s)
Brain , Cerebellum , Frontal Lobe , Magnetic Resonance Imaging , Motor Cortex , Oxygen , Perfusion ImagingABSTRACT
The paper was aimed to summarize the development of vascular depression (VD) in functional magnetic resonance imaging (fMRI) of brain research,including diffusion tensor imaging and blood oxygenation level dependentfMRI.Through the real-time imaging of brain tissues and brain function in VD patients,it was found that the neurological and brain function in the brain regions related to depression were changed.The main pathologic changes were abnormal white matter hyperintensities of the brains.The key link of VD pathogenesis was that limbic systemcortex-striatum-thalamus circuits were destroyed.And the main performance of VD in fMRI was abnormal brain function connection in prefrontal cortex,limbic cortex (i.e.,cingulate gyrus,hippocampal gyrus),amygdala,cerebellum,and etc.in fMRI.The pathogenesis of VD was complex.As a noninvasive living brain function detection technique,fMRI will play an important role in the comprehensive understanding of VD and provide new ideas in clinical diagnosis and treatment.
ABSTRACT
Objective To analyze the value of resting state BOLD-fMRI in the early diagnosis of brain injury after nasopharyngeal carcinoma radiotherapy.Methods Four groups of nasopharyngeal carcinoma patients,including before radiotherapy group (G0),0-3 months after radiotherapy group (G1), 3-6 months after radiotherapy group (G2) and 6-9 months after radiotherapy group (G3),were underwent a resting state BOLD-fMRI scan, and Matlab software DPARSF tool was used to analyze and postprocess the data based on G1-G0,G2-G0,G3-G0,G2-G1,G3-G2 and G3-G1.Results Compared with the G0 group,the activity of bilateral hippocampus and temporal lobes was decreased in G1 and G2 groups,and the decreased degree in G2 group was smaller than that in G1 group.Compared with G1 group,brain metabolic activity increased in G2 and G3 group,but did not return to the initial level before radiotherapy.Conclusion Abnormal changes of resting state BOLD-fMRI have an important clinical significance in early diagnosis of radiation-induced brain injury after nasopharyngeal carcinoma radiotherapy.
ABSTRACT
Regional cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) in young and elderly participants were assessed using pulsed arterial spin labeling (ASL) and blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) techniques in combination with inhalation of CO2. Pulsed ASL and BOLD-MRI were acquired in seventeen asymptomatic volunteers (10 young adults, age: 30±7 years; 7 elderly adults, age: 64±8 years) with no history of diabetes, hypertension, and neurological diseases. Data from one elderly participant was excluded due to the incorrigible head motion. Average baseline CBF in gray matter was significantly reduced in elderly (46±9 mL·100 g-1·min-1) compared to young adults (57±8 mL·100 g-1·min-1; P=0.02). Decreased pulsed ASL-CVR and BOLD-CVR in gray matter were also observed in elderly (2.12±1.30 and 0.13±0.06 %/mmHg, respectively) compared to young adults (3.28±1.43 and 0.28±0.11 %/mmHg, respectively; P<0.05), suggesting some degree of vascular impairment with aging. Moreover, age-related decrease in baseline CBF was observed in different brain regions (inferior, middle and superior frontal gyri; precentral and postcentral gyri; superior temporal gyrus; cingulate gyri; insula, putamen, caudate, and supramarginal gyrus). In conclusion, CBF and CVR were successfully investigated using a protocol that causes minimal or no discomfort for the participants. Age-related decreases in baseline CBF and CVR were observed in the cerebral cortex, which may be related to the vulnerability for neurological disorders in aging.
Subject(s)
Humans , Male , Female , Adult , Middle Aged , Aged , Young Adult , Aging/physiology , Brain/blood supply , Brain/diagnostic imaging , Carbon Dioxide/metabolism , Cerebrovascular Circulation/physiology , Magnetic Resonance Imaging/methods , Spin Labels , Age Factors , Analysis of Variance , Brain Mapping/methods , Oxygen/metabolism , Reference Values , Statistics, Nonparametric , Time FactorsABSTRACT
Objective To evaluate the functional features of motor function area in patients with meningioma by blood oxygenation level dependent functional magnetic resonance imaging (BOLD-fMRI).Methods fMRI were obtained from 10 patients who suffered from meningioma which was adjacent to the motor function cortex.Probabilistic independent component analysis method was used for data analysis.Preoperative and postoperative line Karnofsky Performance Scale (KPS)score was used to assess the patient’s condition.Re-sults Contralateral primary motor cortex and the supplementary motor cortex motor functions were observed in all the activation clusters,in which one side activation area compared with the contralateral activation zone was symmetrical in 6 cases,and significant shift in 4 cases.In 4 patients with the movement function activated,tumor extrusion function shift forward or backwardwith tensile deforma-tion were found.Conclusion BOLD-fMRI imaging technology can effectively locate motor functional area for patients with meningi-oma,which can provide preoperative surgical planning.
ABSTRACT
ABSTRACT. Olfactory perception, although restricted to just a few contexts in everyday life, is key in medicine. Several dementia conditions have been associated with early loss of olfactory discrimination. Despite the fact that several brain areas have been associated with olfaction in functional magnetic resonance imaging (fMRI), the mechanisms by which emotional valence is conveyed to the brain are not fully understood. Methods. In this study, we compared cerebral activations by olfactory stimuli using different emotional valence stimuli on event-related fMRI. We used three standard olfactory odorants with different valence (positive, neutral and negative). Forty-three healthy subjects (22 males) were scanned on a 3.0T MR system. Olfactory stimulation was attained through a delivery system synchronized with image acquisition and subjects´ breathing instructions. fMRI data analysis was performed by the FSL package (Oxford University) including head movement correction, GLM modeling of the neurovascular (BOLD) response and group activation maps produced at p<0.05 and corrected for multiple comparison. Results. Increased cerebral responses within the anterior cingulate, amygdaloid nuclei, as well as the dorsolateral prefrontal, occipital and orbitofrontal cortices were observed in positive and negative valence conditions, while response to neutral valence arousal was less intense and not observed in the amygdaloid complex. The most significant statistical response aroused from the stimuli clusters was observed in the negative condition. Conclusion. The results of the present study support the hypothesis that neutral stimuli may be more sensitive to early losses in pathological conditions, particularly dementia.
RESUMO. Apesar de praticamente restrita a alguns contextos na rotina diária, a percepção de estímulos olfativos é bastante relevante em medicina. Várias condições patológicas, e em particular as demências, estão associadas à perda precoce da capacidade de discriminação e percepção olfativa. Apesar de estudos de ressonância magnética funcional (RMf), terem identificado várias áreas cerebrais relacionadas à percepção olfativa, ainda não sabemos quais destas são moduladas pela valência emocional do estímulo olfativo. Neste estudo investigamos o padrão de resposta cerebral à odorantes com diferentes valências emocionais em indivíduos saudáveis estudados por RMf relacionada à eventos. Métodos. Comparamos a resposta cerebral em um desenho de RMf relacionado à eventos e com uso de três estímulos olfatórios padronizados e com diferentes valências emocionais (positiva, neutra e negativa). Quarenta e três indivíduos normais (22 homens) foram estudados por RMf relacionada à eventos em aparelho de 3T. A estimulação olfativa foi realizada por meio de sistema sincronizado à aquisição das imagens e às instruções dadas aos sujeitos. A análise dos dados foi feita por meio do software FSL (Universidade de Oxford) e incluiu correções de movimento, modelagem de sinal com técnica GLM e mapas de grupo com nível de significância < 0,5. Resultados. As respostas cerebrais no cíngulo anterior, bem como no córtex dorsolateral pré-frontal, occipital e órbitofrontal foram observadas nas condições de valência positiva e negativa, porém a resposta ao estímulo neutro foi menos intensa e não foi observada em complexos amigdaloides. A resposta estatística mais significante foi observada no cluster de estímulos com valência negativa. Conclusão. Estes dados representam evidências para a hipótese de que possivelmente a perda da percepção discriminativa de estímulos com valência emocional neutra pode ser mais sensível em relação às manifestações iniciais de condições patológicas, inclusive demências.
Subject(s)
Humans , Smell , Magnetic Resonance Imaging , Magnetic Resonance Spectroscopy , OdorantsABSTRACT
Objective To investigate the clinical value of blood oxygen level-dependent functional magnetic resonance imaging (BOLD-FMRI) in guiding the dose reduction and functional protection of the motor cortex during postoperative radiotherapy for brain astrocytoma.Methods This study included 27 brain astrocytoma patients with tumors near the motor cortex,who underwent routine MRI and BOLD-FMRI before postoperative radiotherapy.The location and scope of the motor cortex,which were acquired based on BOLD-FMRI results,were marked on positioning CT images,so that the motor cortex would be dealt with as organs at risk.The dose to the motor cortex was reduced as much as possible while ensuring the therapeutic dose to the target area.Finally,the radiotherapy plan that would reduce the mean received dose of the motor cortex was formulated and compared with the routine plan that could not reduce the received dose.Results With the protective radiotherapy plan,the mean received dose of the motor cortex decreased 0.76％-59.20％ (mean 30.78％) on the affected side and 23.33％-68.30％ (mean 48.07％) on the unaffected side;the coefficients of variation were 71.41％ on the affected side and 36.71％ on the unaffected side.Conclusions BOLD-FMRI can help to reduce the received dose of the motor cortex while ensuring the therapeutic dose to the target area when formulating the postoperative radiotherapy plan for brain astrocytoma,thus protecting the motor function and improving patients' quality of life.
ABSTRACT
Objective To establish Walker-256 transplantation tumor model in SD Rats.To study of R2 * signal changes on murine Walker-256 tumor after inhaling Carbogen by blood oxygen level dependent (BOLD)-MR,and to explore the feasibility of BOLD-MRI on detecting tumor hypoxia.Methods Walker-256 tumor cell implanted subcutaneously in right lower abdomen of 95 female SD rats.MR was performed on the tumor-forming rats when the maximum diameter of tumor reached 1-3 cm,using a 3.0 T MR scanner equipped with a 3 inch animal surface coil BOLD-MRI was done by using a multiecho SPGR sequence during inhaling air and at 10 minute after inhaling Carbogen,respectively.All images were transferred to GE ADW 4.3 workstation,then a baseline R2* (R2 * a) and R2 * (R2 * b) after inhaling Carbogen of tumor was calculated using R2 Star analysis software and △R2 * was calculated through △R2 * =R2 * b-R2 * a,meanwhile the volume of tumor were calculated as well.The difference of R2 * signal preand post-inhaling of Carbogen was compared with a paired t test,Pearson correlation was calculated between R2 * a,△R2 * and the volume of tumor,respectively.The correlation between △R2 * and R2 * a was also assessed by Pearson correlation.Results Sixty-eight of ninety-five female SD rats formed the tumor (71.6％).The volume of tumor was from 352 to 13 173 mm3.Mean △R2* decreased significantly (-2.26 ±3.90) s-1 from (41.18 ±22.29) s-1 during breathing air to(38.91 ±21.35) s-1 10 min after inhaling Carbogen (t =4.01,P ＜ 0.01).△R2 * was inversely correlated with R2 * (r =-0.32,P ＜ 0.05).The △R2 * was well correlated with volume of tumor (r =0.35,P ＜ 0.05),but R2 * a was not correlated with volume of tumor(r =-0.03,P ＞ 0.05).Conclusions BOLD-MRI can detect the R2 * signal change of murine Walker-256 tumor pre-and post-inhaling of Carbogen.The R2 * signal showed significant decrease after inhaling Carbogen,however,the individual variation was remarkable.
ABSTRACT
[Objective]Although warm-tube moxibustion is easy-to-use in acupuncture therapy, the timing of moxa removal varies among practitioners. In the present study, we used near infrared spectroscopy (NIRS) to compare effects of different durations of moxibustion stimulation on improvement in local circulation as measured by changes in blood oxygenation dynamics in muscle tissue.<BR>[Methods]Twelve healthy adults underwent warm-tube moxibustion with a single cone applied to the upper right shoulder region;measurements of tissue blood oxygenation dynamics (ΔOxy-Hb, ΔTotal-Hb) were obtained at intervals of 0.5 s. Control measurements were first taken for 15 min without intervention (Control);then, subjects received moxibustion 2 min after the start of measurement and had the moxa removed at the following time points: 30 s after patients experienced heat pain (Removal 30, moxibustion group); 45 s after heat pain (Removal 45, moxibustion group);or did not have the moxa removed (Continuous moxibustion group). These 4 different conditions were compared. Additionally, we determined the burning temperature of moxa and the skin temperature and intensity of heat pain sensation at the site of moxibustion.<BR>[Results]Compared with the Control, the Removal 30, Removal 45, and Continuous moxibustion groups had significant increases in ΔOxy-Hb, ΔTotal-Hb, and skin temperature, with no significant differences among the moxibustion groups. No significant difference in the intensity of heat pain sensation was observed among the moxibustion groups. All moxibustion groups began to show rapid increases in both ΔTotal-Hb and ΔOxy-Hb around the time when subjects began to feel heat pain, suggesting that the axon reflex evoked by noxious stimuli of heat pain increased blood volume and arterial blood flow.<BR>[Conclusion]Hemodynamic improvement in muscle tissue through the use of continuous warm-tube moxibustion for 30 s or longer after the occurrence of heat pain was confirmed.
ABSTRACT
Objective BOLD-fMRI was used to observe the activated auditory cortex evoked by pure tone stimuli in patients with sensorineural hearing loss and this paper is to discuss the objective measure for patient with sensorineural hearing toss. Methods BOLD-fMRI examinations were taken in 22 patients with unilateral moderate to severe sensorneural hearing loss and 15 control subjects. The volumes and intensities of the two hemispheres of the activated auditory cortex were analyzed quantitatively. Results Significant activation was found in the temporal lobe in control subjects, and significant differences in the volume and intensity were noted between the contralateral and ipsilateral activated auditory cortexes in them (P<0.01), exhibiting clearly eontralateral predominance. When the normal ear of patients with sensorineural hearing loss received signals, there was no significant difference be-tween contralateral and ipsilateral activated auditory cortexes (P>0.05). Conclusion When the normal ear of pa-tients with sensorneural hearing loss was stimulated by pure tone, the contralateral hemisphere predominance disap-peared. This result seems to show the plasticity of auditory cortex of patients with unilateral hearing loss.
ABSTRACT
Objective To establish the analyzing methods for functional MR images, and investigate the effects of electroacupuncture stimulation to human brain function. Methods Electroacupuncture stimulation was performed at Guangming (GB37) and Waiguan (SJ5) acupoints in 5 healthy subjects, who had been scanned with Sonata 1.5T MRI (Siemens). Brain activity was measured with Statistical Parameter Mapping (SPM) software. Results Electroacupuncture stimulation of Guangming (GB37) and Waiguan (SJ5) acupoints produced prominent increases of fMRI signals in visual cortex and inferior parietal lobule. Conclusion Electroacupuncture stimulation of multiple acupoints can activate the specific areas of brain cortices. The fMRI technique and SPM analysis are powerful new tools to study the mechanism of electroacupuncture stimulation.
ABSTRACT
Objective To investigate the effects of ultraviolet blood irradiation and oxygenation(UBIO)on oxygen free radical metabolism(OFRM)in rabbits with acute soman intoxication.Methods One hundred rabbits were randomly divided into five groups:a control group,a soman intoxication group(I),a soman intoxication plus routine therapy group(TR),a soman intoxication plus UBIO therapy group(UBIO)and a soman intoxication plus complex therapy group(CT).All the rabbits were intervened accordingly.Then the concentrations of malondiade- hyde(MDA)and the activities of superoxide dismutase(SOD),glutathionperoxidase(GSH Px)and catalase (CAT)in serum were determined at 14 d after various treatments.Results Compared with the control group,the concentration of MDA and the activity of CAT in the 1 group were significantly increased(P＜0.01),while the activi- ties of SOD and GSH Px were obviously decreased(P＜0.05).After UBIO or complex therapy,the serum level of MDA was significantly decreased in comparison with that in the I group(P＜0.01),while the concentrations of SOD, GSH Px and CAT were enhanced(P＜0.05).Conclusion UBIO therapy can improve antioxidation activity against the injury caused by free radicals and could be used to treat acute soman intoxication,which causes injury from in- creased oxygen free radical concentrations.