脑血管畸形磁共振血管成像与脑血管造影对照研究

目的：探讨了ＴＯＦ法ＭＲＡ评价脑血管畸形的价值及限度，材料与方法：２９例经ＭＲＩ（ｎ＝２９），脑血管造影（ｎ＝１５）和／或手术病理（ｎ＝１０）证实的脑血管畸形（ＡＶＭ２４例，ＡＶＦ２例，隐匿性ＡＶＭ３例）患者进行ＴＯＦ法ＭＲＡ检查，应用１．０Ｔ超导ＭＲ系统的二维或三维ＦＩＳＰ序列（预置０～３条预饱和带）和ＭＩＰ图像后处理技术，１５例同时经股动脉行全脑血管造影，采用Ｋａｐｐａ统计量对两种血管成像方法     

脑血管狭窄与闭塞的MRA与DSA对照研究

目的：评价ＭＲＡ诊断脑血管狭窄与闭塞的价值又限度，并对假阳性、假阴性进行分析。材料与方法：对１４例患者的１２０根正常、狭窄与闭塞血管进行３Ｄ－ＴＯＦ ＭＯＴＳＡ ＭＲＡ和ＤＳＡ对照分析。结果：１４例１２０根血管ＭＲＡ与ＤＳＡ诊断相符合血管数为１０９根（９０．８％），ＭＲＡ对正常脑血管的敏感性、特异性、准确性分别为９１％、９０．３％、９０．８％；对狭窄血管分别为８３．３％、９２．１％、９０．８％；对     

儿童脑血管疾病的临床与磁共振成像的对照研究

目的：探讨脑血管疾病在未成年人群中的表现特点。方法：患儿124例，检查方法选用磁共振T1、T2加权像和磁共振血管成像。结果：检查显示本组病例中有单纯脑出血9例，脑动脉闭塞或狭窄90例，脑血管畸形25例。结论：儿童脑血管疾病表现特点主要有：（1）发病率随年龄增大而下降；（2）年龄越小急性发病的可能性越大；（3）相当多的患儿没有脑卒中的典型症状；（4）脑动脉闭塞或狭窄均累及脑动脉主干，年龄越小多支动脉受累越多见；（5）在脑血管畸形病例中，非典型性的脑血管发育异常较多见。     

脑动脉瘤磁共振血管成像与脑血管造影对照研究

目的：探讨三维时间飞跃法磁共振血管成像（３ＤＴＯＦＭＲＡ）评价脑动脉瘤的价值与限度。材料与方法：２９例临床及影像学证实的脑动脉瘤患者行常规ＭＲＩ和３ＤＴＯＦＭＲＡ检查，应用１．０Ｔ超导ＭＲ系统，扫层远端预置饱和带３ＤＦＩＳＰ序列和最大强度投影（ＭＩＰ）图像后处理技术。１３例同时行脑血管造影，采用Ｓｅｌｄｉｎｇｅｒ技术穿刺股动脉选择性全脑血管造影，快速摄片（３～４帧／秒）；结果：ＭＲＡ对脑动脉瘤的敏感性和特异性分别为９２．３％和８３．３％，结合ＭＲＩ，其特异性提高到１００％。较准确地显示了直径３～１５ｍｍ动脉瘤的形态、大小及与载瘤动脉的关系，对３ｍｍ以下或１５ｍｍ以上动脉瘤显示欠佳，主要由于其分辨率较低或瘤内血栓或涡流形成等所致；结论：３ＤＴＯＦＭＲＡ对脑动脉瘤有诊断价值。     

实验性部分免脑组织切除术后早期影像学与病理学对照研究

目的 探讨正常脑组织部分切除术后早期的MRI特点和病理学基础。方法 选取36只健康新西兰大白兔，按术后1－10d的不同时间将动物分成10个组，3、5、7、10d组各6只动物，其余各组为2只动物。3％戊巴比妥耳缘静脉注射麻醉，无菌状态下切除右顶枕部分脑组织分别在术后1－10d行平扫及增强MR检查，随后立即取材，电子显微镜及普通光学显微镜下观察组织病理改变。结果 （1）术后24h术区边缘出现正常脑组织的反应性增强；（2）术后一直到第5天反应性强化程度逐渐加重，5d之后变化不明显；（3）术后3d之内反应性增强为血脑屏障的破坏所致,3d之后为新生小血管和破坏的血脑屏蔽共同起作用，主要机制是新生血管数量的增加。结论 正常脑组织在术后早期反应性强化特点表现出明显的时间过程，在不同时间、血脑屏障的破坏和新生血管的数量对反应性增强所起的作用是不同的。     

黑白花和杂种乳牛的经济与生物学特性

作者介绍了黑白花母牛与荷斯坦公牛在具有不同饲养水平和牛群生产力水平的农场的杂交结果。杂交效果在许多方面决定于荷斯坦公牛的遗传质量。黑白花品种母牛对杂种后代的生产力影响不大。用高产牛群杂交最有效。分析了杂种乳牛的适应能力及物质代谢障碍的问题。 许多国家包括苏联都强化利用荷斯坦牛来获得高产乳牛。良种场和世界高产记录乳牛所达到的产量指标都证明它的遗传潜力很大。无论是产奶量还是乳脂产量的最新最高记录都是荷斯坦品种牛创造的。纯种繁殖和改良其它品种都广泛利用荷斯坦牛。     

脑组织快速病理制片方法的实验研究

1　材料和方法选自本院病理科 2 0 0 0 - 0 1～ 2 0 0 1- 0 4脑组织快速病理标本共计 36 2例均行快速石蜡切片 (其中 2 17例同时行冷冻切片 )。冷冻切片使用日本樱花牌ＣＭ - 4 1型恒冷式冷冻切片机 ,组织包埋剂为ＯＣＴ包埋剂 ,组织经包埋、- 12～ - 16℃冷冻 2～ 4ｍｉｎ ,切片 4～ 6 μｍ ,丙酮固定后ＨＥ染色。快速石蜡切片使用ＰＨＴ - 4 0 0型病理样品快速超声处理仪 (上海震康医疗器材有限公司 ) ,水浴锅的温度为 6 5～ 70℃ ,组织 (个别组织太小 ,用擦镜纸包裹 )经 10 %福尔马林液 (2 0ｍｌ)固定2～ 3ｍｉｎ ,用吸水纸去除组织表面…     

速效抗晕胶囊抗运动病作用的实验研究

目的研究速效抗晕胶囊抗运动病效果。方法采用大鼠条件性厌食症模型观测旋转刺激前后糖精水饮用量的变化;观测毕格犬旋转刺激后流涎、呕吐潜伏期变化。结果旋转刺激前,各组间大鼠糖精水饮用量没有差别;旋转刺激后对照组糖精水饮用量较旋转前明显减少（P〈0．01）,而茶苯海明组、速效抗晕胶囊低、中、高剂量组大鼠糖精水饮用量较旋转前无显著性差别。给药前毕格犬对于旋转刺激均敏感,其流涎、呕吐出现时间较早;给药后,茶苯海明组、速效抗晕胶囊低剂量组流涎、呕吐潜伏期变化不明显,而速效抗晕胶囊中、高剂量组与对照组比较,流涎、呕吐潜伏期显著延长（P〈0．01）。结论速效抗晕胶囊具有抗运动病作用,并且效果优于茶苯海明。     

急性重型脑损伤脑组织氧分压监测及临床意义

目的研究急性重型脑损伤患者脑组织氧分压(PbtO2)的变化及临床意义.方法选择急性重型脑损伤患者20例,行PbtO2持续监测,同时行颅内压(ICP)、脑灌注压(CPP)、动脉血氧分压(PaO2)、动脉血二氧化碳分压(PaCO2)测定.分析PbtO2的变化规律及影响因素.结果 (1)患者PbtO2在监测期内的变化有4种形式.在伤后立即或早期出现PbtO2进行性下降者提示预后不良.(2)伤后CPP、PaO2、PaCO2明显影响患者PbtO2.(3)电极的平均零点漂移为(1.5±0.8) mm Hg,平均灵敏度漂移为(-0.9±15.3)%;没有发生与插入电极相关的并发症.结论脑组织氧分压监测是一种安全、可靠、准确的脑氧监测方法,可反映出重型脑损伤后的脑组织缺血缺氧情况,并有助于合理调整治疗方案,提示预后.     

双压力导管植入体比格犬体内植入手术的实施及在安全药理学研究中的应用

目的应用植入式遥测技术建立清醒比格犬动物模型,为药物临床前安全药理学评价研究提供理想的动物模型。方法选择6～8月龄、整体状况良好的比格犬,戊巴比妥钠（40 mg/kg,iv）麻醉后,通过外科手术,分别在胸腔、腹腔以及皮下植入呼吸压力导管、植入体主体和生物电（ECG）测定电极,股动脉插入血压测定压力导管,并进行细致周到的术后护理以防并发症的发生。植入手术成功后通过无线电遥测装置,经DSI清醒动物遥测系统自动记录、储存和分析动物在清醒状态下ECG、血压、呼吸和温度等生理参数。结果与结论成功地建立了植入式清醒比格犬动物模型,获得了稳定的ECG、呼吸、血压、体温等图形和数据。植入手术的操作及术后护理是建立植入式清醒比格犬动物模型成败的关键因素。     

The reproducibility and sensitivity of brain tissue volume measurements derived from an SPM-based segmentation methodology

PURPOSE: To investigate the reproducibility of SPM99-based whole brain, gray matter, and white matter volume measurements with and without image inhomogeneity correction, subsequently exploring age and gender effects on absolute and fractional (proportional to intra-cranial) volumes. MATERIALS AND METHODS: Twenty-seven control subjects (aged 23.2 to 55.2 years) had three-dimensional fast spoiled gradient recall scans. Ten subjects were scanned about 197 days later. RESULTS: Coefficients of variation (CV) for absolute and fractional volumes determined from images processed with inhomogeneity correction ranged from 1.2% to 0.5%. Inhomogeneity correction reduced the CV for all measures except gray matter fractional (GMF) volumes. Significantly lower white matter absolute (WM) and fractional (WMF) volumes, and higher GMF were found in females compared with males, overlying age-related reductions (in decreasing order of significance) in brain parenchymal fraction, GMF, WMF, brain parenchymal, and gray matter volumes. CONCLUSION: SPM99 segmentations are sufficiently reproducible to detect age and gender effects in limited cohorts.     

HPLC测定血浆和脑组织中文拉法辛的浓度

目的:建立测定血浆和脑组织中文拉法辛的方法.方法:血浆和脑组织样品均用液-液萃取法,正己烷:异戊醇(99:1)萃取.色谱柱Agilent Zorbax Eclipse×DB-C8(4.6 mm× 150 mm,5 μm),流动相以乙腈:磷酸钾缓冲液(25:75);流速1.4 ml/min;室温;进样量20 μl;检测波长229 nm.结果:在0.25～32.00 μg/ml范围内,血浆中文拉法辛浓度与峰面积的线性关系良好(r=0.9999);在0.05～6.40 μg/ml,脑组织中文拉法辛浓度与峰面积也呈良好的线性关系(r=0.9994).血浆回收率为89.4%,血浆中文拉法辛浓度在0.5,4.0,32.0 μg/ml的日内变异系数(SD)分别为3.7%～5.5%,1.6%～5.2%和4.2%～5.7%,日间SD分别为6.5%,5.0%和2.0%,最低检测浓度为0.15 μg/ml.脑匀浆回收率是93.3%,脑匀浆文拉法辛浓度在0.5,4.0,32.0 μg/ml的日内SD分别为2.2%～3.4%,1.3%～6.0%和0.6%～3.4%,日间SD分别为4.1%,3.4%和5.6%,最低检测线为0.25 μg/ml.结论:建立了文拉法辛在血浆和脑组织中的高效液相色谱分离测定方法.该方法准确、重复性好、选择性强,适用于大鼠体内药代动力学研究和脑组织中药物浓度的测定.     

Detection of asymptomatic cerebral microbleeds: a comparative study at 1.5 and 3.0 T

RATIONALE AND OBJECTIVES: The magnitude of iron-induced susceptibility changes in gradient echo T2*-weighted magnet resonance imaging (T2* MRI) increases with the field strength and should increase the sensitivity for detection of cerebral microbleeds (CMBs) at 3.0 T. To test these hypotheses, we prospectively examined individuals with documented CMBs at 1.5 and 3.0 T. MATERIALS AND METHODS: Five hundred fifty elderly individuals, who participated in an interdisciplinary study of healthy aging, were examined at 3.0 T using T2* MRI sequences (repetition time [TR]/echo time [TE]/flip angle [FA] = 573 ms/16 ms/18 degrees ). Individuals positive for CMBs were asked to undergo an additional examination at 1.5 T (TR/TE/FA = 663 ms/23 ms/18 degrees ). Images were analyzed independently by two observers. CMBs were counted throughout the brain and were qualitatively analyzed comparing the degree of visible hypointensity on a 5-point scale from 1 (complete signal loss) to 5 (no detection) for both field strengths. Contrast-to-noise ratio of CMBs to surrounding brain tissue was calculated. RESULTS: At 3.0 T, CMBs were detected in 45 of 550 individuals; 25 agreed to an additional examination at 1.5 T. In this group (n = 25), a total of 53 CMBs were detected at 3.0 T, compared to 41 CMBs at 1.5 T. The mean contrast-to-noise ratio of CMBs was significantly increased at 3.0 T compared to 1.5 T (27.4 +/- 8.2 vs. 17.4 +/- 8.0; p < .001). On qualitative analysis, visibility of CMBs was ranked significantly higher at 3.0 T (1.3 +/- 0.4 vs. 2.9 +/- 1.1; p < .001). CONCLUSION: Evidence of past microbleeds may even be found in neurologically normal elderly individuals by MRI. Detection rate and visibility of CMBs benefit from the higher field strength, resulting in a significantly improved depiction of iron-containing brain structures (CMBs) at 3.0 T with potential clinical relevance.     

99mTc-HL91显像在缺血性脑血管病中脑乏氧组织的应用研究

目的 探讨99mTc-4,9-二氮.3,3,10,10-四甲基十二烷-2,11-二酮肟(99mTc-HL91)在缺血性脑血管病中脑乏氧组织的临床应用价值.方法 对9例对照组和17例急性脑梗死患者于起病7 d内进行脑乏氧显像,同时进行了CT或MRI检查.其中2例分别于第一次显像阳性后9 d和12 d进行第二次乏氧显像.结果 对照组未见脑实质有明显核素浓聚,左侧,右侧比值为0.98±0.04.17例急性脑梗死患者中,乏氧显像阳性11例,阳性率64.7%,其患侧/健侧比值为1.54±0.55,与对照组比较有显著性差异(t=3.081,P＜0.05).结论 99mTc-HL91显像可以区分乏氧与坏死的脑组织,对指导治疗、评价疗效有一定的临床意义.     

Optimizing brain tissue contrast with EPI: a simulated annealing approach.

A new magnetization preparation and image acquisition scheme was developed to obtain high-resolution brain images with optimal tissue contrast. The pulse sequence was derived from an optimization process using simulated annealing, without prior assumptions with regard to the number of radiofrequency (RF) pulses and flip angles. The resulting scheme combined two inversion pulses with the acquisition of three images with varying contrast. The combination of the three images allowed separation of gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) based on T1, contrast. It also enabled the correction of small errors in the initial T1 estimates in postprocessing. The use of three-dimensional (3D) sensitivity-encoded (SENSE) echo-planar imaging (EPI) for image acquisition made it possible to achieve a 1.15(3) mm3 isotropic resolution within a scan time of 10 min 21 s. The cortical GM signal-to-noise ratio (SNR) in the calculated GM-only image varied between 30 and 100. The novel technique was evaluated in combination with blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) on human subjects, and provided for excellent coregistration of anatomical and functional data.     

大剂量人体白蛋白和硫酸镁对溶栓后脑组织的保护与促进修复作用

目的 评价rt-PA溶栓治疗联合大剂量人体白蛋白与硫酸镁延长溶栓时间窗的可能性和可靠性.方法 健康雄性成年SD大鼠40只,对血栓法建立的急性大鼠大脑中动脉栓塞(MACO)模型随机分为4组.A组:缺血3 h,rt-PA单纯溶栓(对照组,10只);B组:缺血6 h,rt-PA单纯溶栓(10只);C组:缺血6 h,rt-PA溶栓 人体白蛋白(10只);D组:缺血6 h,rt-PA溶栓 人体白蛋白 硫酸镁(10只).rt-PA(10 mg/kg)与20%人体白蛋白(2.5 g/kg)分别从大鼠股静脉缓慢注入,人体白蛋白在脑缺血3 h开始注射,1 h内完成;5%硫酸镁溶液(500 mg/kg)在脑缺血3 h和18 h自腹腔注射.于治疗前、治疗后24 h、7 d、14 d行MRI检查,在治疗14 d MRI检查结束后立即处死,行病理学检查(包括光镜、电镜和免疫组化)、激光扫描共聚焦显微镜检查.结果 ①溶栓治疗后14 d与治疗前比较,A、B、C、D 4组中脑梗死体积分别缩小5.07%、2.58%、10.18%和35.40%,以D组缩小最为明显.②4组间梗死边缘区相对脑血流量(rCBV)在4个时间段分别比较差异均有统计学意义(P均<0.05).③4组中大鼠的生存时间以D组最长,以B组最短,4组之间存活时间比较差异无统计学意义(F=0.188,P=0.904).④激光扫描共聚焦显微镜显示C组、D组脑梗死边缘区微血管轻度扩张,有少量、局限的荧光物质渗出,较B组明显减少.⑤免疫组化显示C组与D组脑梗死边缘区胶质纤维酸性蛋白(GFAP)增生活跃,与B组比较增生层较厚且密集.⑥电镜结果显示C组、D组神经元核形态基本正常,线粒体轻度肿胀.星形细胞足板轻度空泡化,较B组损害程度轻.结论 rt-PA溶栓治疗联合人体白蛋白、硫酸镁明显缩小脑梗死体积,提高脑梗死边缘区rCBV速率,促进星形细胞增生.研究表明rt-PA溶栓治疗联合大剂量人体白蛋白、硫酸镁,能有效地延长溶栓时间窗,可以延长至脑缺血 6 h内.     

Simultaneous MRI acquisition of blood volume, blood flow, and blood oxygenation information during brain activation.

Simultaneous acquisition of complementary functional hemodynamic indices reflecting different aspects of brain activity would be a valuable tool for functional brain-imaging studies offering enhanced detection power and improved data interpretation. As such, a new MRI technique is presented that is able to achieve concurrent acquisition of three hemodynamic images based primarily on the changes of cerebral blood volume, blood flow, and blood oxygenation, respectively, associated with brain activation. Specifically, an inversion recovery pulse sequence has been designed to measure VASO (vascular space occupancy), ASL (arterial spin labeling) perfusion, and BOLD (blood-oxygenation-level-dependent) signals in a single scan. The MR signal characteristics in this sequence were analyzed, and image parameters were optimized for the simultaneous acquisition of these functional images. The feasibility and efficacy of the new technique were assessed by brain activation experiments with visual stimulation paradigms. Experiments on healthy volunteers showed that this technique provided efficient image acquisition, and thus higher contrast-to-noise ratio per unit time, compared with conventional techniques collecting these functional images separately. In addition, it was demonstrated that the proposed technique was able to be utilized in event-related functional MRI experiments, with potential advantages of obtaining accurate transient information of the activation-induced hemodynamic responses.     

99mTc-HL91显像在缺血陛脑血管病中脑乏氧组织的应用研究

目的 探讨99mTc-4,9-二氮。3,3,10,10-四甲基十二烷-2,11-二酮肟(99mTc-HL91)在缺血性脑血管病中脑乏氧组织的临床应用价值。方法 对9例对照组和17例急性脑梗死患者于起病7 d内进行脑乏氧显像,同时进行了CT或MRI检查。其中2例分别于第一次显像阳性后9 d和12 d进行第二次乏氧显像。结果 对照组未见脑实质有明显核素浓聚,左侧,右侧比值为0.98±0.04.17例急性脑梗死患者中,乏氧显像阳性11例,阳性率64.7%,其患侧/健侧比值为1.54±0.55,与对照组比较有显著性差异(t=3.081,P<0.05)。结论 99mTc-HL91显像可以区分乏氧与坏死的脑组织,对指导治疗、评价疗效有一定的临床意义。