全颅放射治疗与联合威猛治疗脑转移瘤的疗效比较

目的评价全颅放疗联合威猛治疗脑转移瘤的疗效.方法单纯全颅放疗20例(Ⅰ组),联合威猛治疗组23例(Ⅱ组),Ⅰ,Ⅱ组放疗总剂量为40 Gy/4～5周,然后针对病灶缩野补充20 Gy/2～3周.联合威猛化疗在放疗20～30Gy/2～3周后开始,100mg/d,共3～5 d,4周为1周期.结果局部控制率、局部复发率和因脑转移瘤所致死亡率2组分别为65.0%和20.0%,65.0%和73.9%,8.7%和26.1%.Ⅱ组与Ⅰ组比较局部控制率、局部复发率和因脑转移瘤所致死亡率均有显著差异(P＜0.05).结论联合威猛治疗脑转移瘤在提高局部控制率,降低局部复发率方面优于单纯全颅放疗.     

Comparison of MR perfusion imaging and microsphere measurements of regional cerebral blood flow in a rat model of middle cerebral artery occlusion

The purpose of this investigation was to correlate magnetic resonance (MR) perfusion measurements with absolute regional cerebral blood flow (rCBF) in a rat model of focal ischemia. The MR perfusion measurements were made using dynamic first-pass bolus tracking of a susceptibility contrast agent, whereas rCBF was measured using radioactive microspheres. Two simple MR perfusion parameters, the maximum change in ( ) and time delay to ( ), were derived from the signal intensity versus time curves on a pixel-to-pixel basis, without applying curve-fitting procedures or tracer kinetic theory. In each hemisphere, and were compared with the rCBF measurements in four selected regions of interest. Sixteen MR bolus tracking series were performed in 12 rats with occlusion of the middle cerebral artery. In all of the individual series there was a significant correlation (.0001 ≤ p ≤ .02) between and the microsphere rCBF measurements, with correlation coefficients ranging from .784 to .983. Pooling the data resulted in a correlation coefficient of .809 (p = .0001). There was a nonlinear correlation between the and rCBF. For both parameters there was considerable variation between different measurements regarding both the slope of the regression line and its intercept with the y-axis. Our results justify the use of as a relative measure of perfusion during acute cerebral ischemia. Because of the interindividual variation, calibration of MR perfusion measurements for the estimation of absolute flow values must be considered unreliable. The may have physiological relevance as a marker of collateral flow.     

盐酸甲氯芬酯在急性脑出血中的临床应用疗效观察

目的观察盐酸甲氯芬酯治疗急性脑出血临床病例疗效。方法将62例脑出血患者进行随机均分治疗组和对照组。对照组用常规治疗方法,治疗组在常规治疗的基础上,加用盐酸甲氯芬酯0．5g,静脉滴注,每日1次,共4周。于治疗前及治疗后第4周后分别进行神经功能缺损评分及疗效评定。结果治疗4周后,治疗组神经功能缺损评为（9．6±6．3）分,明显低于对照组的（14．4±7．6）分（P〈0．05）;治疗组的显效率和有效率分别为61．29％和87．10％,显著高于对照组的38．71％和54．85％（P〈0．05）。结论盐酸甲氯芬酯可促进脑出血患者的神经功能保护和康复作用。     

磁共振灌注及弥散成像在早期脑梗塞诊断的价值

磁共振弥散加权成像和血流灌注成像不仅可以超早期诊断脑梗塞，明确缺血部位，范围，估计缺血半暗带的大小和鉴别短暂性脑缺血发作；特殊磁共振序列还可以确诊早期颅出血，有助于溶栓对象的筛选和预后的判断。为溶栓治疗提供直观的影像学依据。     

人硫氧还蛋白对脑缺血作用的CT灌注与SOD相关性的实验研究

目的研究人硫氧还蛋白(hTRX)对局灶性兔脑缺血/再灌注损伤后脑组织的保护作用,并探讨其清除氧自由基的生物学活性.方法采用线栓法制成一侧兔脑缺血/再灌注模型(栓塞6 h,再灌注18 h),将25只雄性新西兰白兔随机分成假手术组(Sham组,5只)、缺血/再灌注组(I/R组,10只)和缺血/再灌注 hTRX治疗组(I/R hTRX组,10只),I/R hTRX组给予hTRX(0.75 mg/kg体质量),Sham组、I/R组以等容积的生理盐水取代hTRX;分别于梗死后6 h及再灌注后18 h做CT灌注图像,观察脑梗死面积,计算出其所占同侧大脑半球面积的百分比(HLA%);检测脑组织匀浆中SOD,MDA含量.结果脑缺血/再灌注后,脑梗死范围显著,脑组织匀浆中SOD明显下降,MDA明显升高(与假手术组比较,P<0.01);而应用hTRX能显著减小脑梗死面积,降低MDA及升高SOD含量(与B组比较,P<0.01).结论重组hTRX对脑缺血/再灌注损伤有显著的治疗作用.     

速碧林联合纳络酮治疗急性脑梗死疗效观察

目的观察速碧林联合纳络酮治疗急性脑梗死的临床效果。方法采用速碧林0.4ml皮下注射每天1次,纳络酮1.2m g 0.9%NS250ml静点,1次d/。结果联合用药疗效优于单一用药组(P<0.01)。结论速碧林联合纳络酮治疗急性脑梗死治愈率高,显效及肌力开始恢复的时间明显提前。     

Perfusion in rat brain at 7 T with arterial spin labeling using FAIR-TrueFISP and QUIPSS

Measurement of perfusion in longitudinal studies allows for the assessment of tissue integrity and the detection of subtle pathologies. In this work, the feasibility of measuring brain perfusion in rats with high spatial resolution using arterial spin labeling is reported. A flow-sensitive alternating recovery sequence, coupled with a balanced gradient fast imaging with steady-state precession readout section was used to minimize ghosting and geometric distortions, while achieving high signal-to-noise ratio. The quantitative imaging of perfusion using a single subtraction method was implemented to address the effects of variable transit delays between the labeling of spins and their arrival at the imaging slice. Studies in six rats at 7 T showed good perfusion contrast with minimal geometric distortion. The measured blood flow values of 152.5±6.3 ml/100 g per minute in gray matter and 72.3±14.0 ml/100 g per minute in white matter are in good agreement with previously reported values based on autoradiography, considered to be the gold standard.     

Absolute quantification of cerebral blood flow: correlation between dynamic susceptibility contrast MRI and model-free arterial spin labeling

Purpose

To compare absolute cerebral blood flow (CBF) estimates obtained by model-free arterial spin labeling (ASL) and dynamic susceptibility contrast MRI (DSC-MRI), corrected for partial volume effects (PVEs).

Methods

CBF was measured using DSC-MRI and model-free ASL (quantitative signal targeting with alternating radiofrequency labeling of arterial regions) at 3 T in 15 subjects with brain tumor, and the two modalities were compared with regard to CBF estimates in normal gray matter (GM) and DSC-to-ASL CBF ratios in selected tumor regions. The DSC-MRI CBF maps were calculated using a global arterial input function (AIF) from the sylvian-fissure region, but, in order to minimize PVEs, the AIF time integral was rescaled by a venous output function time integral obtained from the sagittal sinus.

Results

In GM, the average DSC-MRI CBF estimate was 150±45 ml/(min 100 g) (mean±SD) while the corresponding ASL CBF was 44±10 ml/(min 100 g). The linear correlation between GM CBF estimates obtained by DSC-MRI and ASL was r=.89, and observed DSC-to-ASL CBF ratios differed by less than 3% between GM and tumor regions.

Conclusions

A satisfactory positive linear correlation between the CBF estimates obtained by model-free ASL and DSC-MRI was observed, and DSC-to-ASL CBF ratios showed no obvious tissue dependence.     

Application of FT-based MMSE deconvolution method for cerebral blood flow measurement in patients with leukoaraiosis

Introduction

The bolus-tracking (BT) technique is the most popular perfusion-weighted (PW) dynamic susceptibility contrast MRI method used for estimating cerebral blood flow (CBF), cerebral blood volume and mean transit time. The BT technique uses a convolution model that establishes the input–output relationship between blood flow and the vascular tracer concentration. Singular value decomposition (SVD)- and Fourier transform (FT)-based deconvolution methods are popular and widely used for estimating PW MRI parameters. However, from the published literature, it appears that SVD is more widely accepted than other methods. In a previous article, an FT-based minimum mean-squared error (MMSE) technique was proposed and simulation experiments were performed to compare it with the well-established circular SVD (oSVD) method. In this study, the FT-based MMSE method has been used to estimate relative CBF (rCBF) in 13 patients with white matter lesions (WMLs) (leukoaraiosis), and results are compared with the widely used oSVD method.

Materials and Methods

Thirteen patients with leukoaraiosis were imaged on a 1.5-T Siemens whole-body scanner. After acquiring the localizer and structural scans consisting of FLAIR (fluid attenuated with inversion recovery), T₁-weighted and T₂-weighted images, perfusion study was implemented as part of the MRI protocol. For each patient and method, two values were calculated: (a) rCBF for normal white matter (NWM) ROI, obtained by dividing the average CBF value in NWM ROI with average CBF in gray matter (GM) ROI, and (b) rCBF for WML ROI, obtained by dividing the average CBF value in WML ROI with average CBF in GM ROI. Results for the two deconvolution methods were computed.

Results and Discussion

A significant (P<.05) decrease in estimated rCBF was observed in the WML in all the patients using the MMSE method, while for the oSVD method, the decrease was observed in all but one patient. Initial results suggest that the MMSE method is comparable to the oSVD method for estimating rCBF in NMW while it may be better than oSVD for estimating rCBF in lesions of low flow. Studies involving a larger patient population may be required to further validate the findings of this work.     

威廉环毛蚓Pheretima guillelmi(Michaelsen)神经内分泌系统的研究

以威廉环毛蚓为实验材料,对其神经内分泌系统的显微、亚显微结构及其对体表水交换的影响作了初步研究.通过大量的实验,说明在威廉环毛蚓的中枢神经系统中存在三种不同类型的细胞,即A、B和C三种细胞.A细胞数量最多,位于脑神经节、咽下神经节和腹神经索中.B细胞主要位于咽下神经节.C细胞主要位于咽下神经节和腹神经索中.神经内分泌活动与季节有关,A细胞和C细胞的分泌活动随季节变化而不同,B细胞的内分泌活动受季节的影响不大.蚯蚓体表的水交换受神经内分泌调控,这种因子仅存在于脑神经节内.