Emotion processing in Parkinson's disease: a blood oxygenation level-dependent functional magnetic resonance imaging study

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.

Blood oxygen level–dependent functional magnetic resonance imaging can evaluate the efficiency of transcatheter arterial chemoembolization in hepatocellular carcinoma

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.

Alteration of functional connectivity in patients with Alzheimer’s disease revealed by resting-state functional magnetic resonance imaging

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.

Multimodality magnetic resonance imaging in hepatic encephalopathy: An update

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.

Functional magnetic resonance imaging and the brain: A brief review

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.

Central swallowing in normal adults using functional magnetic resonance imaging

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.

Morphological and functional evaluation of chronic kidney disease using magnetic resonance imaging

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.

Blood Oxygenation Level-dependent Magnetic Resonance Imaging of Breast Cancer： Correlation with Carbonic Anhydrase IX and Vascular Endothelial Growth Factor

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.

Temporally shifted hemodynamic response model helps to extract acupuncture-induced functional magnetic resonance imaging blood oxygenation-level dependent activities

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.

Advanced imaging techniques in the therapeutic response of transarterial chemoembolization for hepatocellular carcinoma

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.

2型糖尿病患者肾功能损伤及氧合水平的BOLD MRI分析

目的 探讨采用血氧水平依赖磁共振成像(BOLD MRI)技术分析2型糖尿病(diabetes mellitus type2,T2DM)患者的估算肾小球滤过率(estimated glomerular filtration rate,eGFR)不同水平的肾缺氧改变。方法 选取T2DM患者以及同期健康正常者共78例,其中64例T2DM患者作为T2DM组,14例同期健康正常者作为对照组,均进行BOLD MRI检查。根据eGFR将64例T2DM患者又分为eGFR正常组(A组)、轻度功能损害组(B组)、中重度肾功能损害组(C组),测定肾脏髓质、皮质R2*(MR2*、CR2*)。采用单因素方差分析数据MR2*、CR2*的组间差异及其与eGFR的相关性,并采用受试者工作特征曲线(receiver operating characteristic cure, ROC)分析MR2*、CR2*值的诊断效能。结果 与对照组相比,A、B、C组MR2*、CR2*值均显著升高,差异有统计学意义(P均<0.05),均与eGFR呈正相关(P均<0.05),均可鉴别T2DM组与对照组,但MR2*值的鉴别敏感度稍高。结论 BOLD MRI可无创评估T2DM患者早期肾脏功能性缺氧改变,监测eGFR不同阶段的肾脏氧合水平,对临床治疗具有指导意义。

MRI用于胶质瘤神经重塑的研究进展

胶质瘤是成人最常见的恶性脑肿瘤,复发率高且预后极差。神经重塑是大脑在胶质瘤生长中发生的复杂而精密的适应性反应,深入理解大脑的神经重塑对于改善胶质瘤病人生活质量,延长病人生存期具有重要意义。利用高分辨三维T1加权成像(3D T1WI)、扩散张量成像(DTI)及血氧水平依赖功能MRI(BOLD-fMRI)等技术,同时结合先进的影像分析方法可以探索胶质瘤病人结构和功能方面的可塑性及其相关机制。就不同MRI技术对胶质瘤病人结构和功能重塑的研究进行综述,并展望未来的研究方向。

Detection of 100% oxygen induced changes in retina using magnetic resonance imaging： a human study

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.

多参数功能MRI评价冷缺血再灌注肾损伤大鼠肾脏血流及氧合水平的价值

目的探讨动脉自旋标记(ASL)和血氧水平依赖(BOLD)技术评估冷缺血再灌注损伤(CIRI)大鼠肾脏血流和血氧微观改变的价值。方法将100只健康雄性SD大鼠随机分为4组,分别为肾脏冷缺血1 h组(CIRI 1 h)、冷缺血2 h组(CIRI 2 h)、冷缺血4 h组(CIRI 4 h)组及假手术组(CIRI 0 h),每组25只。每组随机选取5只分别在术前、术后(1 h、1 d、2 d、5 d)进行ASL及BOLD MRI,测量肾皮质的血流量(RBFCo)值及T_(2)^(*)值(T_(2)^(*)Co)、肾外的髓外带T_(2)^(*)值(T_(2)^(*)OSOM)和肾外髓内带T^(2*)值(T^(2*)ISOM)。随后切除大鼠左肾进行病理学分析并对肾小管损伤程度评分。采用单因素方差分析比较各组间及组内的不同时间点之间MRI参数和大鼠肾小管损伤程度评分之间的差异;采用Pearson相关分析MRI参数间及MRI参数与肾小管损伤程度评分的相关性。结果术后1 h,冷缺血组大鼠肾脏RBFCo、T_(2)^(*)_(Co)、T_(2)^(*)_(OSOM)值均较术前减低(均P<0.05);术后5 d,CIRI 0 h、CIRI 1 h组的RBFCo、T_(2)^(*)_(Co)、T_(2)^(*)_(OSOM)、T^(2*)_(ISOM)值恢复至其术前水平(均P>0.05),CIRI 4 h组上述指标仍低于术前水平(均P<0.05)。术后1 h、1 d、2 d,CIRI 4 h组T_(2)^(*)OSOM值均较其他各组低;术后5 d,CIRI 4 h组RBFCo、T^(2*)_(Co)、T^(2*)_(OSOM)、T^(2*)_(ISOM)值均低于CIRI 0 h组(均P<0.05)。CIRI 2 h组、CIRI 4 h组的术后各时间点的肾小管损伤程度评分均高于其术前(均P<0.05),术后随时间延长,评分呈减低趋势;术后各时间点,CIRI 4 h组评分均较CIRI 0 h、CIRI 1 h组高;术后1 h、2 d、5 d,CIRI 2 h组的评分均较CIRI 0 h、CIRI 1 h组的要高(均P<0.05)。RBF_(Co)、T_(2)^(*)Co、T_(2)^(*)_(OSOM)、T^(2*)_(ISOM)值与肾小管损伤评分均呈中度负相关(r=-0.714、-0.689、-0.518、-0.579,均P<0.001);RBFCo值与T_(2)^(*)_(Co)、T^(2*)_(OSOM)、T^(2*)_(ISOM)值呈中度正相关(r=0.704、0.525、0.612,均P<0.001);T_(2)^(*)_(Co)值与T_(2)^(*)_(OSOM)、T_(2)^(*)_(ISOM)值呈中度正相关(r=0.685、0.572,均P<0.001);T_(2)^(*)_(OSOM)值与T_(2)^(*)_(ISOM)值呈中度正相关(r=0.606,P<0.001)。结论ASL和BOLD成像可动态评估肾CIRI后组织血流及氧合水平的微观变化,为早期发现肾CIRI提供影像学依据。

重度抑郁症患者杏仁核的磁共振成像研究进展

重度抑郁症(major depressive disorder,MDD)是一种严重的精神障碍性疾病,主要表现为情绪低落、兴趣和快感丧失以及出现自杀倾向等。杏仁核是情绪加工和调节的关键区域之一,在MDD的发病机制中起着重要作用。MRI技术的应用揭示了MDD患者杏仁核在结构、功能和代谢等方面的变化,对于MDD的早期诊断、疾病监测和疗效评估具有重要的临床意义。因此,本文将对不同MRI技术在MDD杏仁核中的相关研究予以综述,以期为深入解析MDD的病理机制及发展诊疗策略提供支持。

非增强T1-mapping、DKI、BOLD-MRI在评估IgA肾病患者肾功能中的应用价值研究

目的:探讨非增强T1-mapping磁共振,扩散峰度成像(diffusion kurtosis imaging,DKI)及血氧饱和水平依赖成像(blood oxygenation level-dependent MRI,BOLD-MRI)在IgA肾病(immunoglobulin A nephropathy,IgAN)患者的肾功能评估中的应用价值,并对各项MRI参数的评估效用进行比较。方法:纳入经肾活检确诊的57例IgAN患者以及19名健康志愿者,根据肾功能不全严重程度[肾小球滤过率(estimated glomerular filtration rate,eGFR)水平]将IgAN患者分为轻度损害组[≥60 mL/(min·1.73 m^(2))]、中度损害组[30~<60 mL/(min·1.73 m^(2))]、重度损害组[<30 mL/(min·1.73 m^(2))],比较对照组与IgAN组各亚组间的肾脏MRI参数,分析T1-mapping(T1值)、DKI(Fak、MK、MD值)、BOLD-MRI(R2*值)与肾功能评估指标如eGFR、血清肌酐(serum creatinine,Scr)及胱抑素C(cystatin C,CysC)等的相关性,探索3种肾脏MRI在评估IgAN患者肾功能中的应用价值。结果:对照组与IgAN组T1值差异有统计学意义[(1592.15±89.91)ms vs(1776.30±172.08)ms,P<0.001];IgAN各肾功能不全亚组间T1值两两比较,差异均有统计学意义[轻度损害组(1684.86±103.57)ms、中度损害组(1888.99±182.01)ms、重度损害组(1969.14±133.74)ms,均P<0.001]。对照组与IgAN组Fak值差异有统计学意义[0.15(0.08~0.20)vs 0.19(0.11~0.32),P<0.05],轻度损害组与重度损害组间差异有统计学意义[0.17(0.11~0.25)vs 0.35(0.28~0.40),P<0.01];各组R2*值差异均无统计学意义。IgAN组T1值与eGFR、血红蛋白(hemoglobin,Hb)、红细胞压积(hematocrit,HCT)呈负相关(r=-0.620、-0.679、-0.629,均P<0.001),与Scr、CysC呈正相关(r=0.559、0.604,均P<0.001);Fak值与eGFR呈负相关(r=-4.004,P<0.05),与Scr、CysC呈正相关(r=0.366、0.378,P<0.05,P<0.01);MD值与Hb、HCT呈正相关(r=0.472、0.498,P<0.001);R2*值与各项临床指标皆无相关性;T1值预测IgAN肾功能轻、中、重度的AUC分别为0.791(95%CI:0.660~0.922,P<0.01)、0.972(95%CI:0.914~1.000,P<0.01)、0.988(95%CI:0.958~1.000,P<0.01);Fak值预测IgAN重度肾功能损害的AUC为0.883(95%CI:0.678~1.000,P<0.01)。结论:非增强T1-mapping、DKI对IgAN患者的肾功能状态具有预测价值,且非增强T1-mapping的预测价值优于DKI。

脑氧代谢率的功能磁共振成像方法

目的提出一种可用于脑氧代谢率(Cerebral Metabolic Rate of Oxygen,CMRO_(2))功能磁共振成像研究的方法——基于灌注的多回波非对称性自旋回波(Perfusion Multiecho Asymmetric Spin Echo,PMASE)技术。方法PMASE技术主要结合了流动敏感交替反转恢复技术与多回波非对称性自旋回波技术,可同步测量得到脑血流量(Cerebral Blood Flow,CBF)和脑氧摄取分数(Oxygen Extraction Fraction,OEF)的动态变化,根据菲克定律最终实现对CMRO_(2)动态变化的测量。研究通过右手握拳任务设计验证该技术的可行性。结果所有受试者的CBF和OEF激活区都位于左侧运动皮层,且右手握拳任务引起的CBF、OEF和CMRO_(2)的相对变化分别为-21.4%±4.5%、48.2%±9.6%和16.1%±8.3%,与先前的研究结果保持一致。结论PMASE技术具有为探索脑功能和疾病相关的CMRO2提供新的功能磁共振成像技术的潜力。

磁共振定量血氧水平依赖成像对大鼠脑氧代谢评估的可行性研究

目的:探讨磁共振定量血氧水平依赖(qBOLD)成像评估大鼠脑组织氧代谢的可行性。方法:利用7.0 T磁共振成像仪分别对5只健康SD大鼠以及5只C6胶质瘤大鼠麻醉后行qBOLD成像扫描,计算R2*、脑血流量(CBF)、氧饱和度(SO_(2))、氧摄取分数(OEF)和脑氧代谢率(CMRO_(2))。勾画荷瘤大鼠肿瘤组织、对侧脑灰质,记录正常脑组织、并比较肿瘤与对侧健康灰质氧代谢参数差异,研究BOLD成像信号影响因素。结果:健康大鼠灰质和白质的R2*值(单位:Hz)分别为37.4±1.2、36.2±1.7,SO_(2)值分别为66.4±3.2、53.2±2.6(P<0.001),CBF值[单位:mL·(100 g)^(-1)·min^(-1)]分别为105.6±15.3、100.4±18.5(P=0.03),OEF值分别为0.33±0.02、0.31±0.01,CMRO_(2)值[单位:mL·(100 g)^(-1)·min^(-1)]分别为3.8±0.4、3.3±0.3(P<0.01)。荷瘤组大鼠肿瘤及对侧健康组织R2*、SO_(2)、CBF、OEF、CMRO_(2)值分别为37.1±1.8、38.6±16.3,61.4±4.2、63.5±4.3(P=0.02),104.4±16.3、120.3±20.3(P<0.01),0.33±0.02、0.38±0.03(P<0.01),3.6±0.3、3.9±0.6(P=0.04)。结论:磁共振qBOLD成像是评估大鼠脑氧代谢情况可靠、无创方法,可识别胶质瘤组织氧代谢变化。

慢性阻塞性肺疾病患者焦虑与脑功能活动异常的相关性研究

目的分析慢性阻塞性肺疾病(COPD)患者长期慢性低氧状态下的焦虑症状与脑功能活动异常的相关性。方法前瞻性选择21例COPD合并焦虑患者为COPD组,并选取26例性别、年龄相匹配的健康人群为对照组。2组患者均行高分辨率3D-T1加权成像(3D-T1WI)、T2-液体衰减反转恢复(T2-FLAIR)及血氧水平依赖(BOLD)序列检查,应用DPARSF及SPM8软件对2组脑低频振幅(ALFF)值进行分析。结果COPD组患者左海马旁回-扣带回ALFF值增高,右额上回ALFF值减低,差异有统计学意义(P<0.05);Pearson相关性分析发现,右额上回ALFF值与焦虑评分呈负相关(r=-0.485,P=0.03)。结论COPD慢性低氧患者存在右额上回的脑功能活动损害,损害程度与焦虑症状呈正相关,并且可能存在海马旁回-扣带回的脑功能活动代偿性增强。

血氧水平依赖功能MRI在慢性腰痛中的研究进展

慢性腰痛(CLBP)是当前全球范围内最主要的致残疾病之一。许多关键的中枢脑区在慢性腰痛的发生及发展中发挥着关键作用。血氧水平依赖功能MRI(BOLD-fMRI)是研究大脑中各脑区神经元活动的无创性成像技术,在探究大脑功能变化与疾病进展间的关系发挥着重要作用。现就BOLD-fMRI在CLBP发病机制和不同治疗评估中的研究进展进行综述。