Parkinson's disease is a neurodegenerative disorder caused by loss of dopamine neurons in the substantia nigra pars compacta. Tremor, rigidity, and bradykinesia are the major symptoms of the disease. These motor i...Parkinson's disease is a neurodegenerative disorder caused by loss of dopamine neurons in the substantia nigra pars compacta. Tremor, rigidity, and bradykinesia are the major symptoms of the disease. These motor impairments are often accompanied by affective and emotional dysfunctions which have been largely studied over the last decade. The aim of this study was to investigate emotional processing organization in the brain of patients with Parkinson's disease and to explore whether there are differences between recognition of different types of emotions in Parkinson's disease. We examined 18 patients with Parkinson's disease(8 men, 10 women) with no history of neurological or psychiatric comorbidities. All these patients underwent identical brain blood oxygenation level-dependent functional magnetic resonance imaging for emotion evaluation. Blood oxygenation level-dependent functional magnetic resonance imaging results revealed that the occipito-temporal cortices, insula, orbitofrontal cortex, basal ganglia, and parietal cortex which are involved in emotion processing, were activated during the functional control. Additionally, positive emotions activate larger volumes of the same anatomical entities than neutral and negative emotions. Results also revealed that Parkinson's disease associated with emotional disorders are increasingly recognized as disabling as classic motor symptoms. These findings help clinical physicians to recognize the emotional dysfunction of patients with Parkinson's disease.展开更多
Hepatocellular carcinoma(HCC) is among the most common malignant tumors worldwide, and transcatheter arterial chemoembolization(TACE) technology has become the first-line treatment for advanced HCC. Another important,...Hepatocellular carcinoma(HCC) is among the most common malignant tumors worldwide, and transcatheter arterial chemoembolization(TACE) technology has become the first-line treatment for advanced HCC. Another important, recently developed technique is blood oxygen level–dependent functional magnetic resonance imaging(BOLD-fMRI), which utilizes hemoglobin as an endogenous contrast agent and measures deoxygenated hemoglobin content by sampling the oxygen content of tissues, thus reflecting the hemodynamics and pathophysiologic changes in body organs. Currently this technology is being used in patients with liver tumors;that is, it serves as an important tool in follow-up after TACE. The present paper summarizes these developments.展开更多
The main symptom of patients with Alzheimer’s disease is cognitive dysfunction. Alzheimer’s disease is mainly diagnosed based on changes in brain structure. Functional connectivity reflects the synchrony of function...The main symptom of patients with Alzheimer’s disease is cognitive dysfunction. Alzheimer’s disease is mainly diagnosed based on changes in brain structure. Functional connectivity reflects the synchrony of functional activities between non-adjacent brain regions, and changes in functional connectivity appear earlier than those in brain structure. In this study, we detected resting-state functional connectivity changes in patients with Alzheimer’s disease to provide reference evidence for disease prediction. Functional magnetic resonance imaging data from patients with Alzheimer’s disease were used to show whether particular white and gray matter areas had certain functional connectivity patterns and if these patterns changed with disease severity. In nine white and corresponding gray matter regions, correlations of normal cognition, early mild cognitive impairment, and late mild cognitive impairment with blood oxygen level-dependent signal time series were detected. Average correlation coefficient analysis indicated functional connectivity patterns between white and gray matter in the resting state of patients with Alzheimer’s disease. Functional connectivity pattern variation correlated with disease severity, with some regions having relatively strong or weak correlations. We found that the correlation coefficients of five regions were 0.3–0.5 in patients with normal cognition and 0–0.2 in those developing Alzheimer’s disease. Moreover, in the other four regions, the range increased to 0.45–0.7 with increasing cognitive impairment. In some white and gray matter areas, there were specific connectivity patterns. Changes in regional white and gray matter connectivity patterns may be used to predict Alzheimer’s disease;however, detailed information on specific connectivity patterns is needed. All study data were obtained from the Alzheimer’s Disease Neuroimaging Initiative Library of the Image and Data Archive Database.展开更多
Hepatic encephalopathy(HE) is a neuropsychiatric complication of cirrhosis or acute liver failure. Currently, HE is regarded as a continuous cognitive impairment ranging from the mildest stage, minimal HE to overt HE....Hepatic encephalopathy(HE) is a neuropsychiatric complication of cirrhosis or acute liver failure. Currently, HE is regarded as a continuous cognitive impairment ranging from the mildest stage, minimal HE to overt HE. Hyperammonaemia and neuroinflammation are two main underlying factors which contribute to the neurological alterations in HE. Both structural and functional impairments are found in the white mater and grey mater involved in HE. Although the investigations into HE pathophysiological mechanism are enormous, the exact pathophysiological causes underlying HE remain controversial. Multimodality magnetic resonance imaging(MRI) plays an important role in helping to understand the pathological process of HE. This paper reviews the up-to-date multimodality MRI methods and predominant findings in HE patients with a highlight ofthe increasingly important role of blood oxygen level dependent functional MRI.展开更多
Functional magnetic resonance imaging(fMRI) is em-ployed in many behavior analysis studies, with blood oxygen level dependent-(BOLD-) contrast imaging being the main method used to generate images. The use of BOLD-con...Functional magnetic resonance imaging(fMRI) is em-ployed in many behavior analysis studies, with blood oxygen level dependent-(BOLD-) contrast imaging being the main method used to generate images. The use of BOLD-contrast imaging in f MRI has been refined over the years, for example, the inclusion of a spin echo pulse and increased magnetic strength were shown to produce better recorded images. Taking careful precautions to control variables during measurement, comparisons between different specimen groups can be illustrated by f MRI imaging using both quantitative and qualitative methods. Differences have been observed in comparisons of active and resting, developing and aging, and defective and damaged brains in various studies. However, cognitive studies using f MRI still face a number of challenges in interpretation that can only be overcome by imaging large numbers of samples. Furthermore, f MRI studies of brain cancer, lesions and other brain pathologies of both humans and animals are still to be explored.展开更多
BACKGROUND： While brain-imaging studies in healthy adults have indicated that multiple cortical regions are involved in swallowing, these functional imaging techniques have not been extensively applied to the complet...BACKGROUND： While brain-imaging studies in healthy adults have indicated that multiple cortical regions are involved in swallowing, these functional imaging techniques have not been extensively applied to the complete understand neurophysiology of swallowing in China. A full understanding of normal swallowing neurophysiology is important for improving functional outcomes for dysphagia due to neurologic disorders or damage with increasing age. Thus the interpretations of the functional contributions of various brain areas in swallowing should be scientifically researched. OBJECTIVE： To identify the activation and characteristic of swallowing center in healthy adults using functional magnetic resonance imaging. DESIGN, TIME AND SETTING： An uncontrolled neuroimaging study was performed at the Outpatient Clinic, Department of Radiology, West China Hospital of Sichuan University between March and November 2008. PARTICIPANTS： Ten healthy right-handed volunteers, aged over 20 years with a mean age of （34.2 ＋ 8.1） years, a range of 25-45 years and including five males and five females participated. A medical history was obtained from all potential subjects and all subjects were free of systemic diseases and neurological disorders. METHODS： The healthy volunteers were examined with event-related functional magnetic resonance imaging of blood oxygenation level-dependent while laryngeal swallow-related movements were recorded. Subjects were scanned during voluntary saliva swallowing and water bolus swallowing activation tasks. Data was processed using the General Linear Model. A voxel by voxel group comparison was performed using random effect analysis. Any cluster with a corrected P 〈 0.05 for spatial extent was considered significant. MAIN OUTCOME MEASURES： The cerebral cortical activation maps of voluntary swallowing of saliva and swallowing of water bolus in healthy adults were observed. RESULTS： A multifocal cortical representation of swallowing was in the precentral gyrus, postcentral gyrus, insula, anterior cingulate gyrus, thalamus, basal ganglia and cerebellum, in a bilateral and asymmetrical manner, predominantly on the left hemisphere in the volunteers （P 〈 0.05）. CONCLUSION： Activation of the cortex during normal swallowing tasks may be functionally linked to basal nuclei, thalamus, and cerebellum, greatly appearing in the left hemisphere.展开更多
X-ray computed tomography(CT),ultrasonography(US)and radionuclide scanning are important clinical methods for evaluating morphology of the kidney.These modalities are also applicable for estimating kidney function wit...X-ray computed tomography(CT),ultrasonography(US)and radionuclide scanning are important clinical methods for evaluating morphology of the kidney.These modalities are also applicable for estimating kidney function with time lapse analysis using proper contrastmedia as may be necessary.In the case of US,it can estimate kidney function based on the measurement of blood flow using the Doppler effect.Formerly,magnetic resonance imaging(MRI)was an inappropriate diagnostic imaging technique for abdominal organs because of their respiratory displacements.However,MRI is now actively used for kidney as well as liver or other parenchymal organs,in tandem with the technological advances.Unlike unenhanced X-ray CT,"conventional"MRI can distinguish the border between cortex and medulla in T1 or T2 weighted images.It was known that the border blurred with decreasing kidney function.Moreover,several other particular imaging methods were introduced in recent years,and these could be called"functional"MRI.In this review,the following are discussed:functional MRI for chronic kidney disease,which include blood oxygenation level-dependent MRI for evaluation of hypoxia,diffusion-weighted imagingfor evaluation of fibrosis,diffusion tensor imaging for evaluation of microstructure,and arterial spin labeling to evaluate the amount of organ perfusion,accompanied with several related articles.The ultimate goal of functional MRI is to provide useful in vivo information repeatedly for daily medical treatment non-invasively.展开更多
Background： Blood oxygenation level-dependent magnetic resonance imaging （BOLD-MRI） is a functional MRI technique which involves using the paramagnetic properties of deoxyhemoglobin to image the local tissue oxygen...Background： Blood oxygenation level-dependent magnetic resonance imaging （BOLD-MRI） is a functional MRI technique which involves using the paramagnetic properties of deoxyhemoglobin to image the local tissue oxygen concentration. The purpose of this study was to investigate whether BOLD-MRI could evaluate hypoxia and angiogenesis of breast invasive ductal carcinoma （IDC）. Methods： Ninety-eight female patients with IDC were retrospectively included in this research. All patients underwent breast BOLD-MRI at 3.0 T before surgery. R2＊ values of BOLD-MR1 were measured. The expression of carbonic anhydrase IX （CA IX） and vascular endothelial growth factor （VEGF） was analyzed by immunohistochemistry. Spearman＇s correlation analysis was used to correlate R2＊ value with CA IX and VEGF levels. Results： Heterogeneous intensity on BOLD-MRI images was the main finding of IDCs. The mean R2＊ value was 52.8 ± 18.6 Hz. The R2＊ values in patients with axillary lymph node metastasis were significantly higher than the R2＊ values in patients without axillary lymph node metastasis （t = 2.882, P = 0.005）. R2＊ values increased with CA IX level and positively correlated with the level of CA 1X （r = 0.616, P 〈 0.001）; however, R2＊ value had no significantly correlation with the level of VEGF （r = 0.110, P = 0.281）. Conclusion： B OLD-MRI could noninvasively evaluate chronic hypoxia of IDC, but not angiogenesis.展开更多
Background The onsets of needling sensation introduced by acupuncture stimulus can vary widely from subject to subject. This should be explicitly accounted for by the model blood oxygenation-level dependent （BOLD） t...Background The onsets of needling sensation introduced by acupuncture stimulus can vary widely from subject to subject. This should be explicitly accounted for by the model blood oxygenation-level dependent （BOLD） time course used in general linear model （GLM） analysis to obtain more consistent across-subject group results. However, in standard GLM analysis, the model BOLD time course obtained by convolving a canonical hemodynamic response function with an experimental paradigm time course is assumed identical across subjects. Although some added-on properties to the model BOLD time course, such as temporal and dispersion derivatives, may be used to account for different BOLD response onsets, they can only account for the BOLD onset deviations to the extent of less than one repetition time （TR）. Methods In this study, we explicitly manipulated the onsets of model BOLD time course by shifting it with -2, -1, or 1 TR and used these temporally shifted BOLD model to analyze the functional magnetic resonance imaging （fMRI） data obtained from three acupuncture fMRI experiments with GLM analysis. One involved acupuncture stimulus on left ST42 acupoint and the other two on left GB40 and left BL64 acupoints. Results The model BOLD time course with temporal shifts, in addition to temporal and dispersion derivatives, could result in better statistical power of the data analysis in terms of the average correlation coefficients between the used BOLD models and extracted BOLD responses from individual subject data and the T-values of the activation clusters in the grouped random effects. Conclusions The GLM analysis with ordinary BOLD model failed to catch the large variability of the onsets of the BOLD responses associated with the acupuncture needling sensation. Shifts in time with more than a TR on model BOLD time course might be required to better extract the acupuncture stimulus-induced BOLD activities from individual fMRI data.展开更多
Background Inner retinal oxygenation response （△PO2） is a worldwide study focus. However, the relevant reports on its radiological measurments are limited. In this study, magnetic resonance imaging （MRI）, employi...Background Inner retinal oxygenation response （△PO2） is a worldwide study focus. However, the relevant reports on its radiological measurments are limited. In this study, magnetic resonance imaging （MRI）, employing T1 weighted image （T1WI）, was used to detect changes in APO2 following 100% oxygen inhalation in human subjects. Methods MRI was performed on a 1.5-T GE scanner system. After obtaining ophthalmologic data, eleven healthy individuals were given room air and 100% oxygen inhalation in order with different intervals. The MRI TlWl data were collected for 50 minutes. Data were analyzed with NIH IMAGE software. Results APO2 was not panretinally uniform, and changes in oxygenation response were spatially inhomogeneous. During the initial phase （before 5 minutes） of 100% oxygen inhalation, preretinal vitreous water signals in the region of papilla optica increased rapidly. On the contrary, in other regions signals declined. In a later period （35 minutes）, APO2 was panretinally fluctuated and increased slowly and attained homeostasis. After hyperoxia （45 minutes）, delayed-enhancement of preretinal vitreous water signals in regions other than the papilla optica occurred, and then dropped down. There was no significant difference （P 〉0.05） at any consecutive time point during and after hyperoixa. Conclusions These results reveal that hyperoxia can induce region-specific signal changes in preretinal vitreous water. Regulatory activity of the retinal vessel network may be the mechanism during 100% oxygen inhalation. Moreover, MRI is a valuable tool for investigating APO2 and exploring the mechanism of retinal oxygenation response physiologically or pathologically in vivo.展开更多
Hepatocellular carcinoma(HCC) is one of the major causes of morbidity and mortality in patients with chronic liver disease. Transarterial chemoembolization(TACE) can significantly improve the survival rate of patients...Hepatocellular carcinoma(HCC) is one of the major causes of morbidity and mortality in patients with chronic liver disease. Transarterial chemoembolization(TACE) can significantly improve the survival rate of patients with HCC and is the first treatment choice for patients who are not suitable for surgical resections. The evaluation of the response to TACE treatment affects not only the assessment of the therapy efficacy but also the development of the next step in the treatment plan. The use of imaging to examine changes in tumor volume to assess the response of solid tumors to treatment has been controversial. In recent years, the emergence of new imaging technology has made it possible to observe the response of tumors to treatment prior to any morphological changes. In this article, the advances in studies reporting the use of computed tomography perfusion imaging, diffusionweighted magnetic resonance imaging(MRI), intravoxel incoherent motion, diffusion kurtosis imaging, magnetic resonance spectroscopy, magnetic resonance perfusionweighted imaging, blood oxygen level-dependent MRI, positron emission tomography(PET)/computed tomography and PET/MRI to assess the TACE treatment response are reviewed.展开更多
文摘Parkinson's disease is a neurodegenerative disorder caused by loss of dopamine neurons in the substantia nigra pars compacta. Tremor, rigidity, and bradykinesia are the major symptoms of the disease. These motor impairments are often accompanied by affective and emotional dysfunctions which have been largely studied over the last decade. The aim of this study was to investigate emotional processing organization in the brain of patients with Parkinson's disease and to explore whether there are differences between recognition of different types of emotions in Parkinson's disease. We examined 18 patients with Parkinson's disease(8 men, 10 women) with no history of neurological or psychiatric comorbidities. All these patients underwent identical brain blood oxygenation level-dependent functional magnetic resonance imaging for emotion evaluation. Blood oxygenation level-dependent functional magnetic resonance imaging results revealed that the occipito-temporal cortices, insula, orbitofrontal cortex, basal ganglia, and parietal cortex which are involved in emotion processing, were activated during the functional control. Additionally, positive emotions activate larger volumes of the same anatomical entities than neutral and negative emotions. Results also revealed that Parkinson's disease associated with emotional disorders are increasingly recognized as disabling as classic motor symptoms. These findings help clinical physicians to recognize the emotional dysfunction of patients with Parkinson's disease.
基金supported by the National Natural Science Foundation of China (Nos. 81571784 30870695)+2 种基金the Provincial Natural Science Foundation of Hunan (2019JJ531)the Foundation of Hunan Province and Technology Department, China (No. 2015SF2020-4)the Foundation of Hunan Provincial Development and the Reform Commission, China (No. 201583)
文摘Hepatocellular carcinoma(HCC) is among the most common malignant tumors worldwide, and transcatheter arterial chemoembolization(TACE) technology has become the first-line treatment for advanced HCC. Another important, recently developed technique is blood oxygen level–dependent functional magnetic resonance imaging(BOLD-fMRI), which utilizes hemoglobin as an endogenous contrast agent and measures deoxygenated hemoglobin content by sampling the oxygen content of tissues, thus reflecting the hemodynamics and pathophysiologic changes in body organs. Currently this technology is being used in patients with liver tumors;that is, it serves as an important tool in follow-up after TACE. The present paper summarizes these developments.
基金supported by the National Natural Science Foundation of China,No.61401308,61572063(both to XHW)the Natural Science Foundation of Beijing of China,No.L172055(to XHW)+3 种基金the Beijing Municipal Science&Technology Commission Research Fund of China,No.Z171100000417004(to XHW)the China Postdoctoral Fund,No.2018M631755(to XHW)the Special Fund for Improving Comprehensive Strength of Hebei University in the Midwest of China,No.801260201011(to XHW)the High-Level Talent Funding Project—Selective Post-doctoral Research Project Fund of Hebei Province of China,No.B2018003002(to XHW)
文摘The main symptom of patients with Alzheimer’s disease is cognitive dysfunction. Alzheimer’s disease is mainly diagnosed based on changes in brain structure. Functional connectivity reflects the synchrony of functional activities between non-adjacent brain regions, and changes in functional connectivity appear earlier than those in brain structure. In this study, we detected resting-state functional connectivity changes in patients with Alzheimer’s disease to provide reference evidence for disease prediction. Functional magnetic resonance imaging data from patients with Alzheimer’s disease were used to show whether particular white and gray matter areas had certain functional connectivity patterns and if these patterns changed with disease severity. In nine white and corresponding gray matter regions, correlations of normal cognition, early mild cognitive impairment, and late mild cognitive impairment with blood oxygen level-dependent signal time series were detected. Average correlation coefficient analysis indicated functional connectivity patterns between white and gray matter in the resting state of patients with Alzheimer’s disease. Functional connectivity pattern variation correlated with disease severity, with some regions having relatively strong or weak correlations. We found that the correlation coefficients of five regions were 0.3–0.5 in patients with normal cognition and 0–0.2 in those developing Alzheimer’s disease. Moreover, in the other four regions, the range increased to 0.45–0.7 with increasing cognitive impairment. In some white and gray matter areas, there were specific connectivity patterns. Changes in regional white and gray matter connectivity patterns may be used to predict Alzheimer’s disease;however, detailed information on specific connectivity patterns is needed. All study data were obtained from the Alzheimer’s Disease Neuroimaging Initiative Library of the Image and Data Archive Database.
基金Supported by Grants from National Natural Science Foundation of China,Nos.30700194,81171313,81322020 and 81230032(to Zhang LJ)Program for New Century Excellent Talents in University,No.NCET-12-0260(to Zhang LJ)
文摘Hepatic encephalopathy(HE) is a neuropsychiatric complication of cirrhosis or acute liver failure. Currently, HE is regarded as a continuous cognitive impairment ranging from the mildest stage, minimal HE to overt HE. Hyperammonaemia and neuroinflammation are two main underlying factors which contribute to the neurological alterations in HE. Both structural and functional impairments are found in the white mater and grey mater involved in HE. Although the investigations into HE pathophysiological mechanism are enormous, the exact pathophysiological causes underlying HE remain controversial. Multimodality magnetic resonance imaging(MRI) plays an important role in helping to understand the pathological process of HE. This paper reviews the up-to-date multimodality MRI methods and predominant findings in HE patients with a highlight ofthe increasingly important role of blood oxygen level dependent functional MRI.
文摘Functional magnetic resonance imaging(fMRI) is em-ployed in many behavior analysis studies, with blood oxygen level dependent-(BOLD-) contrast imaging being the main method used to generate images. The use of BOLD-contrast imaging in f MRI has been refined over the years, for example, the inclusion of a spin echo pulse and increased magnetic strength were shown to produce better recorded images. Taking careful precautions to control variables during measurement, comparisons between different specimen groups can be illustrated by f MRI imaging using both quantitative and qualitative methods. Differences have been observed in comparisons of active and resting, developing and aging, and defective and damaged brains in various studies. However, cognitive studies using f MRI still face a number of challenges in interpretation that can only be overcome by imaging large numbers of samples. Furthermore, f MRI studies of brain cancer, lesions and other brain pathologies of both humans and animals are still to be explored.
基金Supported by:the National Natural Science Foundation of China,No.30625024Supported by:the National Natural Science Foundation of China,No.30728017+1 种基金Supported by:the National Natural Science Foundation of China,No.30525030National Basic Research Program of China(973 Program),No. 2007CB512305/1
文摘BACKGROUND： While brain-imaging studies in healthy adults have indicated that multiple cortical regions are involved in swallowing, these functional imaging techniques have not been extensively applied to the complete understand neurophysiology of swallowing in China. A full understanding of normal swallowing neurophysiology is important for improving functional outcomes for dysphagia due to neurologic disorders or damage with increasing age. Thus the interpretations of the functional contributions of various brain areas in swallowing should be scientifically researched. OBJECTIVE： To identify the activation and characteristic of swallowing center in healthy adults using functional magnetic resonance imaging. DESIGN, TIME AND SETTING： An uncontrolled neuroimaging study was performed at the Outpatient Clinic, Department of Radiology, West China Hospital of Sichuan University between March and November 2008. PARTICIPANTS： Ten healthy right-handed volunteers, aged over 20 years with a mean age of （34.2 ＋ 8.1） years, a range of 25-45 years and including five males and five females participated. A medical history was obtained from all potential subjects and all subjects were free of systemic diseases and neurological disorders. METHODS： The healthy volunteers were examined with event-related functional magnetic resonance imaging of blood oxygenation level-dependent while laryngeal swallow-related movements were recorded. Subjects were scanned during voluntary saliva swallowing and water bolus swallowing activation tasks. Data was processed using the General Linear Model. A voxel by voxel group comparison was performed using random effect analysis. Any cluster with a corrected P 〈 0.05 for spatial extent was considered significant. MAIN OUTCOME MEASURES： The cerebral cortical activation maps of voluntary swallowing of saliva and swallowing of water bolus in healthy adults were observed. RESULTS： A multifocal cortical representation of swallowing was in the precentral gyrus, postcentral gyrus, insula, anterior cingulate gyrus, thalamus, basal ganglia and cerebellum, in a bilateral and asymmetrical manner, predominantly on the left hemisphere in the volunteers （P 〈 0.05）. CONCLUSION： Activation of the cortex during normal swallowing tasks may be functionally linked to basal nuclei, thalamus, and cerebellum, greatly appearing in the left hemisphere.
文摘X-ray computed tomography(CT),ultrasonography(US)and radionuclide scanning are important clinical methods for evaluating morphology of the kidney.These modalities are also applicable for estimating kidney function with time lapse analysis using proper contrastmedia as may be necessary.In the case of US,it can estimate kidney function based on the measurement of blood flow using the Doppler effect.Formerly,magnetic resonance imaging(MRI)was an inappropriate diagnostic imaging technique for abdominal organs because of their respiratory displacements.However,MRI is now actively used for kidney as well as liver or other parenchymal organs,in tandem with the technological advances.Unlike unenhanced X-ray CT,"conventional"MRI can distinguish the border between cortex and medulla in T1 or T2 weighted images.It was known that the border blurred with decreasing kidney function.Moreover,several other particular imaging methods were introduced in recent years,and these could be called"functional"MRI.In this review,the following are discussed:functional MRI for chronic kidney disease,which include blood oxygenation level-dependent MRI for evaluation of hypoxia,diffusion-weighted imagingfor evaluation of fibrosis,diffusion tensor imaging for evaluation of microstructure,and arterial spin labeling to evaluate the amount of organ perfusion,accompanied with several related articles.The ultimate goal of functional MRI is to provide useful in vivo information repeatedly for daily medical treatment non-invasively.
文摘Background： Blood oxygenation level-dependent magnetic resonance imaging （BOLD-MRI） is a functional MRI technique which involves using the paramagnetic properties of deoxyhemoglobin to image the local tissue oxygen concentration. The purpose of this study was to investigate whether BOLD-MRI could evaluate hypoxia and angiogenesis of breast invasive ductal carcinoma （IDC）. Methods： Ninety-eight female patients with IDC were retrospectively included in this research. All patients underwent breast BOLD-MRI at 3.0 T before surgery. R2＊ values of BOLD-MR1 were measured. The expression of carbonic anhydrase IX （CA IX） and vascular endothelial growth factor （VEGF） was analyzed by immunohistochemistry. Spearman＇s correlation analysis was used to correlate R2＊ value with CA IX and VEGF levels. Results： Heterogeneous intensity on BOLD-MRI images was the main finding of IDCs. The mean R2＊ value was 52.8 ± 18.6 Hz. The R2＊ values in patients with axillary lymph node metastasis were significantly higher than the R2＊ values in patients without axillary lymph node metastasis （t = 2.882, P = 0.005）. R2＊ values increased with CA IX level and positively correlated with the level of CA 1X （r = 0.616, P 〈 0.001）; however, R2＊ value had no significantly correlation with the level of VEGF （r = 0.110, P = 0.281）. Conclusion： B OLD-MRI could noninvasively evaluate chronic hypoxia of IDC, but not angiogenesis.
文摘Background The onsets of needling sensation introduced by acupuncture stimulus can vary widely from subject to subject. This should be explicitly accounted for by the model blood oxygenation-level dependent （BOLD） time course used in general linear model （GLM） analysis to obtain more consistent across-subject group results. However, in standard GLM analysis, the model BOLD time course obtained by convolving a canonical hemodynamic response function with an experimental paradigm time course is assumed identical across subjects. Although some added-on properties to the model BOLD time course, such as temporal and dispersion derivatives, may be used to account for different BOLD response onsets, they can only account for the BOLD onset deviations to the extent of less than one repetition time （TR）. Methods In this study, we explicitly manipulated the onsets of model BOLD time course by shifting it with -2, -1, or 1 TR and used these temporally shifted BOLD model to analyze the functional magnetic resonance imaging （fMRI） data obtained from three acupuncture fMRI experiments with GLM analysis. One involved acupuncture stimulus on left ST42 acupoint and the other two on left GB40 and left BL64 acupoints. Results The model BOLD time course with temporal shifts, in addition to temporal and dispersion derivatives, could result in better statistical power of the data analysis in terms of the average correlation coefficients between the used BOLD models and extracted BOLD responses from individual subject data and the T-values of the activation clusters in the grouped random effects. Conclusions The GLM analysis with ordinary BOLD model failed to catch the large variability of the onsets of the BOLD responses associated with the acupuncture needling sensation. Shifts in time with more than a TR on model BOLD time course might be required to better extract the acupuncture stimulus-induced BOLD activities from individual fMRI data.
文摘Background Inner retinal oxygenation response （△PO2） is a worldwide study focus. However, the relevant reports on its radiological measurments are limited. In this study, magnetic resonance imaging （MRI）, employing T1 weighted image （T1WI）, was used to detect changes in APO2 following 100% oxygen inhalation in human subjects. Methods MRI was performed on a 1.5-T GE scanner system. After obtaining ophthalmologic data, eleven healthy individuals were given room air and 100% oxygen inhalation in order with different intervals. The MRI TlWl data were collected for 50 minutes. Data were analyzed with NIH IMAGE software. Results APO2 was not panretinally uniform, and changes in oxygenation response were spatially inhomogeneous. During the initial phase （before 5 minutes） of 100% oxygen inhalation, preretinal vitreous water signals in the region of papilla optica increased rapidly. On the contrary, in other regions signals declined. In a later period （35 minutes）, APO2 was panretinally fluctuated and increased slowly and attained homeostasis. After hyperoxia （45 minutes）, delayed-enhancement of preretinal vitreous water signals in regions other than the papilla optica occurred, and then dropped down. There was no significant difference （P 〉0.05） at any consecutive time point during and after hyperoixa. Conclusions These results reveal that hyperoxia can induce region-specific signal changes in preretinal vitreous water. Regulatory activity of the retinal vessel network may be the mechanism during 100% oxygen inhalation. Moreover, MRI is a valuable tool for investigating APO2 and exploring the mechanism of retinal oxygenation response physiologically or pathologically in vivo.
基金Supported by Projects of Department of Science and Technology of Sichuan Province,No.2016JY0105
文摘Hepatocellular carcinoma(HCC) is one of the major causes of morbidity and mortality in patients with chronic liver disease. Transarterial chemoembolization(TACE) can significantly improve the survival rate of patients with HCC and is the first treatment choice for patients who are not suitable for surgical resections. The evaluation of the response to TACE treatment affects not only the assessment of the therapy efficacy but also the development of the next step in the treatment plan. The use of imaging to examine changes in tumor volume to assess the response of solid tumors to treatment has been controversial. In recent years, the emergence of new imaging technology has made it possible to observe the response of tumors to treatment prior to any morphological changes. In this article, the advances in studies reporting the use of computed tomography perfusion imaging, diffusionweighted magnetic resonance imaging(MRI), intravoxel incoherent motion, diffusion kurtosis imaging, magnetic resonance spectroscopy, magnetic resonance perfusionweighted imaging, blood oxygen level-dependent MRI, positron emission tomography(PET)/computed tomography and PET/MRI to assess the TACE treatment response are reviewed.
