慢性肝硬化患者神经认知损害与背侧丘脑代谢改变的相关性

目的 分析慢性乙型肝炎肝硬化者认知功能改变与背侧丘脑¹H MRS改变的相关性。方法 收集慢性乙型肝炎肝硬化患者28例（肝硬化组）和同期健康体检者28名（对照组）,分别进行神经心理学测试数字连接试验A （NCT-A）、数字符号试验（DST）和MRS检查;计算各代谢物,包括N-乙酰天门冬氨酸（NAA）、胆碱（Cho）、谷氨酰胺复合物（Glx）和肌醇（mI）的峰下面积与肌酸（Cr）峰下面积的比值（NAA/Cr、Cho/Cr、Glx/Cr及mI/Cr）。结果 与对照组比较,肝硬化组Cho/Cr、mI/Cr减小,Glx/Cr升高,NCT-A时间延长、DST得分减少（P均<0.001）。肝硬化组NCT-A时间与Cho/Cr、mI/Cr呈负相关（r=-0.477,P=0.001;r=-0.695,P<0.001）,与Glx/Cr呈正相关（r=0.665,P<0.001）;DST得分与Cho/Cr、mI/Cr呈正相关（r=0.478,P=0.001;r=0.632,P<0.001）,与Glx/Cr负相关（r=-0.572,P<0.001）。结论 慢性乙型肝炎肝硬化患者神经认知功能障碍可能与背侧丘脑内代谢改变相关。     

1H-MR波谱分析急性期抗N-甲基-D-天冬氨酸受体(NMDAR)脑炎额叶代谢物变化

目的 采用¹H-MR波谱（¹H-MRS）观察急性期抗N-甲基-D-天冬氨酸受体（NMDAR）脑炎双侧额叶代谢物变化及其与认知障碍的关系,评估其应用价值。方法 采集20例急性期抗NMDAR脑炎患者（脑炎组）和20名健康成年人（对照组）双侧额叶¹H-MRS,获得相应MRS及各代谢物N-乙酰天门冬氨酸（NAA）、胆碱（Cho）、肌醇（mI）、谷氨酸盐复合物（Glx）和肌酸（Cr）的峰下面积,计算NAA/Cr、Cho/Cr、mI/Cr及Glx/Cr比值。记录脑炎组脑脊液抗NMDAR抗体滴度检测结果,以简易精神状态检查量表（MMSE）和蒙特利尔认知评估（MoCA）量表评估2组认知功能,比较组间¹H-MRS参数差异,并分析其与抗NMDAR脑炎患者MMSE评分、MoCA评分及与脑脊液抗NMDAR抗体的相关性。结果 脑炎组双侧额叶NAA/Cr、Cho/Cr、mI/Cr、Glx/Cr差异均无统计学意义（t=1.03、2.29、－0.73、0.15,P均>0.05）。与对照组相比,脑炎组双侧额叶NAA/Cr下降、Glx/Cr升高（P均<0.05）,而双侧额叶Cho／Cr、mI/Cr差异均无统计学意义（P均>0.05）。脑炎组双侧额叶NAA/Cr、Cho/Cr、mI/Cr及Glx/Cr与MMSE评分、MoCA总分和脑脊液抗NMDAR抗体均无明显相关性（P均>0.05）。结论 ¹H-MRS有助于诊断急性期抗NMDAR脑炎及监测病情;抗NMDAR脑炎急性期双侧额叶NAA/Cr降低、Glx/Cr升高,但与认知障碍无明显相关。     

MAGiC技术诊断新生儿高胆红素血症

目的 观察MAGiC技术诊断新生儿高胆红素血症(NHB)的价值。方法 前瞻性纳入33例NHB新生儿作为NHB组,以30名正常新生儿为对照组;行MAGiC序列颅脑MR扫描,记录苍白球、壳核及丘脑ROI定量值,包括T1、T2弛豫值及质子密度(PD)值,并计算苍白球/壳核定量比值。比较组间各脑区定量值及定量比值,绘制受试者工作特征曲线,计算曲线下面积(AUC)以评估诊断效能,并以Pearson相关性分析评估血清总胆红素(TSB)水平与各脑区定量值及定量比值的相关性。结果 组间各脑区T1、T2及PD值差异均无统计学意义(P均＞0.05);NHB组苍白球/壳核T1值比值、T2值比值均小于对照组(P均＜0.05)。苍白球/壳核T1值比值诊断NHB的AUC为0.79(P＜0.05);而苍白球/壳核T2值比值诊断NHB的效能低(AUC=0.63,P＞0.05)。TSB与苍白球T2值(r=－0.299,P＜0.05)、苍白球/壳核T1值比值(r=－0.480,P＜0.05)及苍白球/壳核T2值比值(r=－0.328,P＜0.05)均呈负相关。结论 以MAGiC技术获取苍白球/壳核T1值比值对于诊断NHB具有一定价值。     

豆状核区1H-MR波谱代谢物比值诊断新生儿缺氧缺血性脑病

目的 观察豆状核区¹H-MR波谱(¹H-MRS)代谢物比值诊断新生儿缺氧缺血性脑病(HIE)的价值。方法 将78例HIE足月新生儿分为轻度组(n=42)和中重度组(n=36),以同期20例非HIE的其他疾病足月新生儿作为对照组;TE分别取35、135 ms行头颅¹H-MRS,检测豆状核区代谢物N-乙酰天门冬氨酸(NAA)、胆碱复合物(Cho)、肌酸(Cr)及乳酸(Lac)水平,计算NAA/Cr、Cho/Cr、NAA/Cho、Lac/Cr、Lac/Cho及Lac/NAA比值。比较3组间各代谢物比值,分析其与血清神经元特异性烯醇化酶(NSE)和乳酸脱氢酶(LDH)的相关性,观察其诊断HIE的效能。结果 TE为35 ms时,3组Lac/Cr、Lac/Cho及Lac/NAA差异均有统计学意义(P均＜0.05);轻度组Lac/Cr、Lac/Cho及Lac/NAA均低于中重度组(P均＜0.05)而高于对照组(P均＜0.05)。TE为135 ms时,3组NAA/Cr及NAA/Cho差异均有统计学意义(P均＜0.05);轻度组NAA/Cr及NAA/Cho均高于中重度组(P均＜0.05)而低于对照组(P均＜0.05)。TE为35 ms时,血清LDH与Lac/Cho呈弱正相关(r=0.280,P=0.008),与Lac/Cr及Lac/NAA呈低度正相关(r=0.325,P=0.002;r=0.414,P＜0.001);TE为135 ms时,血清NSE与NAA/Cr呈中度负相关(r=－0.584,P＜0.001),与NAA/Cho呈高度负相关(r=－0.857,P＜0.001)。TE取135 ms时,NAA/Cho诊断新生儿HIE的曲线下面积均大于血清NSE及LDH(Z=2.481、2.713,P均＜0.05),以NAA/Cho=0.56为最佳截断值,其诊断敏感度为93.54%,特异度为66.12%。结论 豆状核区¹H-MRS代谢物比值有助于诊断新生儿HIE,TE取135 ms时NAA/Cho诊断效能较佳。     

阻塞型睡眠呼吸暂停低通气综合征患者海马MRS参数与认知功能的相关性

目的 探讨阻塞型睡眠呼吸暂停低通气综合征（OSAHS）患者海马MRS成像参数与认知功能之间的相关性。方法 对31例OSAHS患者（OSAHS组）及28名健康志愿者（对照组）行单体素MRS检查,检测双侧海马NAA、Cho和Cr峰值,计算NAA/Cr、Cho/Cr、NAA/Cho;采用蒙特利尔认知评估量表（MoCA）和简易智能状态量表（MMSE）评估认知功能,分析双侧海马NAA/Cr、Cho/Cr、NAA/Cho与MoCA、MMSE评分间的相关性。结果 OSAHS组双侧海马Cho/Cr较对照组增高,NAA/Cho较对照组减低（P均<0.05）,NAA/Cr差异无统计学意义（P均>0.05）。OSAHS患者双侧海马Cho/Cr与MoCA、MMSE评分呈负相关（P均<0.05）,NAA/Cho与MMSE评分呈正相关（P均<0.05）。结论 OSAHS患者双侧海马MRS参数与认知功能相关,可作为OSAHS患者认知功能损害的神经影像学标记。     

MRS在非海马硬化颞叶癫痫患者中的应用

目的 探讨MRS技术在非海马硬化颞叶癫痫患者中的应用价值。方法 回顾性分析于我院诊治为非海马硬化的单侧颞叶癫痫患者23例（病例组）,选取年龄与之相匹配的20名正常志愿者作为对照组,行常规MR平扫及MRS检查,分析颞叶癫痫患者患侧海马、健侧海马及对照组海马N-乙酰天门冬氨酸（NAA）/肌酸（Cr）、胆碱（Cho）/Cr值的差异;同时评价病例组中接受手术治疗的11例患者的病理及手术结果。结果 病例组患侧海马NAA/Cr值较健侧海马（t=-7.97,P<0.001）及对照组海马降低（t=-9.96,P<0.001）,病例组健侧海马NAA/Cr值与对照组比较差异无统计学意义（t=-1.21,P=0.12）。病例组患侧海马Cho/Cr与健侧（t=0.50,P=0.31）及对照组海马（t=-0.59,P=0.28）差异无统计学意义。11例行致痫侧颞叶切除患者的病理结果显示小范围少量的神经元损伤,神经胶质增生不明显。结论 MRS有助于临床对非海马硬化颞叶癫痫患者的致痫灶进行定侧及定位。     

苍白球T1值诊断急性胆红素脑病

目的 探讨苍白球T1值诊断新生儿急性胆红素脑病（ABE）的价值。方法 对10例ABE（ABE组）、11例高胆红素血症足月新生儿（高胆组）和13名正常新生儿（对照组）行常规T1WI和T1mapping成像。T1mapping成像采用6个不同反转时间的IR-FSE序列,取其平均值,得到量化T1图,选取双侧苍白球为ROI,测量其T1值,以方差分析比较3组间苍白球T1值的差异。对ABE组苍白球T1值与血清间接胆红素的峰值进行Pearson相关性分析,并于生后6个月对患儿发育情况进行评估。结果 常规T1WI显示,ABE组中10例双侧苍白球表现为对称性高信号;高胆组7例表现为高信号,4例为等信号;对照组13名均为等信号。ABE组、高胆组、对照组苍白球T1值分别为（652.40±16.25）ms、（676.45±17.21）ms、（684.08±10.20）ms,差异有统计学意（F=27.97,P<0.01）;ABE组苍白球T1值与对照组、高胆组间差异均有统计学意义（P均<0.05）,而高胆组与对照组间差异无统计学意义（P=0.08）。ABE组苍白球T1值与血清间接胆红素峰值无相关性（r=-0.28,P=0.23）。经过积极治疗,ABE组患儿生后6个月时均无明显神经心理发育障碍。结论 苍白球T1值测量能够提供量化客观依据,结合临床,可为早期诊断新生儿ABE提供帮助。     

基于1H-MRS联合DTI定量检测2型糖尿病患者后扣带回损伤及其与认知功能的相关性

目的 联合运用¹H-MRS和DTI技术检测和评估2型糖尿病（T2DM）患者后扣带回（PCC）脑微结构损伤及脑代谢物异常改变,探讨其与认知功能障碍的相关性。方法 对43例T2DM患者[21例伴认知功能障碍（T2DM+CD组）、22例不伴认知功能障碍（T2DM组）]和23名健康志愿者（HC组）PCC进行单体素MRS及DTI检查,计算各代谢物波峰曲线下面积比值及各向异性分数（FA）、平均弥散率（MD）,并与认知功能指标进行相关性分析。结果 T2DM+CD组PCC脑区肌醇/肌酸（mI/Cr）值高于T2DM和HC组,谷氨酸复合物/肌酸（Glx/Cr）低于T2DM和HC组（P均<0.05）;Glx/Cr与蒙特利尔认知评估量表（MoCA）评分呈正相关（r=0.59,P<0.01）。T2DM+CD组全脑及PCC脑区FA值低于T2DM和HC组,MD值高于T2DM和HC组（P均<0.05）;FA值与MoCA评分呈正相关（r=0.57,P=0.01）。结论 以PCC为兴趣区联合采用¹H-MRS与DTI技术可定量反映T2DM引起认知功能损伤的神经病理学基础,有望成为早期预警的临床指标。     

1H-MRS定量分析糖尿病大鼠腓肠肌代谢物早期评估糖尿病周围神经病变

目的 观察氢质子磁共振频谱（¹H-MRS）检测腓肠肌代谢物对早期评估大鼠糖尿病（DM）模型周围神经病变的价值。方法 将40只SD雄性大鼠随机分为实验组（n=20）与正常组（n=20）。实验组以高糖高脂饲养+注射链脲菌素法建立DM模型。于造模前和造模后7、14、21天采集2组大鼠右下肢腓肠肌¹H-MRS，获得胆碱复合物（Cho）、肌酸复合物（Cr）、细胞内脂质（IMCL）、Cho/Cr及IMCl/Cr值。正常组大鼠予普通饲料喂养。造模后21天行右下肢坐骨神经电生理及病理检查，测量2组坐骨神经运动神经传导速度（MNCV）及感觉神经传导速度（SNCV）。比较实验组内各时间点代谢物浓度值差异及2组间MNCV和SNCV差异，观察病理结果。结果 实验组内不同时间点Cho、Cr、IMCL、Cho/Cr及IMCL/Cr值差异均有统计学意义（F=6.69、5.41、3.65、3.51、3.10，P均<0.05）；造模后14、21天Cr和Cho值均高于造模前（P均<0.05），造模后7天IMCL值高于造模前（P<0.05）。造模后21天实验组右下肢坐骨神经MNCV和SNCV均低于正常组（t=2.74、4.62，P均<0.01）。相比正常组，实验组神经纤维稀疏松散，排列紊乱，部分髓鞘着色浅且不均匀，轴索变细萎缩。结论 ¹H-MRS可无创定量分析骨骼肌代谢，进而早期评估大鼠DM模型DPN。     

不同年龄阿尔茨海默病患者脑核团ADC值与年龄的相关性

目的 探讨不同年龄阿尔茨海默病（AD）患者ADC值与年龄的相关性。方法 选取30例AD患者（AD组）和年龄与之相匹配的30名志愿者（对照组），按年龄段各分为6个亚组[55~59岁（n=3）、60~64岁（n=4）、65~70岁（n=9）、71~74岁（n=5）、75~80岁（n=6）、>80岁（n=3）]，测量双侧海马、红核、尾状核、杏仁体、壳核ADC值，并进行配对t检验、独立样本t检验、单因素方差分析及Pearson相关分析。结果 AD组红核左、右侧ADC值有统计学差异（P=0.022）。AD组不同年龄亚组右侧海马、双侧尾状核、右侧壳核ADC值差异有统计学意义（P均<0.05）；2组不同年龄亚组双侧海马、壳核、尾状核ADC值差异有统计学意义（P均<0.05）。AD组右侧海马（r=0.615，P<0.001）、右侧壳核（r=0.653，P=0.001）及双侧尾状核（左侧：r=0.397，P=0.030；右侧：r=0.429，P=0.020）ADC值与年龄呈正相关。结论 AD患者右侧海马和壳核、双侧尾状核ADC值随年龄增加而增大。ADC值可为临床预测和早期诊断AD脑内右侧海马和壳核、双侧尾状核神经退行性病变提供参考。     

Determination of creatine kinase isoenzyme MB activity in serum using immunological inhibition of creatine kinase M subunit activity. Activity kinetics and diagnostic significance in myocardial infarction.

This is a new method for the determination of creatine kinase isoenzyme MB activity in serum. The method uses direct activity measurement of creatine kinase B subunit activity after blocking of CK-M subunit activity by inhibiting antibodies. The test takes no longer than 15 min. The method yields an intra-serial C.V. of 2.0-12.9%, and a C.V. from day to day of 5.5%. The detection limit is 3.4 U/l creatine kinase MB. In the 95 cases with proven myocardial infarction several types of creatine kinase MB activity kinetics could be determined. The percentage of creatine kinase MB of peak CK-total is 6-25%, with a mean of 11.1%. The amount of creatine kinase MB with respect to total CK activity after reinfarction is higher than the amount after initial infarction.     

Dissociable correlates of two classes of retrieval processing in prefrontal cortex

Although substantial evidence suggests that the prefrontal cortex (PFC) implements processes that are critical for accurate episodic memory judgments, the specific roles of different PFC subregions remain unclear. Here, we used event-related functional magnetic resonance imaging to distinguish between prefrontal activity related to operations that (1) influence processing of retrieval cues based on current task demands, or (2) are involved in monitoring the outputs of retrieval. Fourteen participants studied auditory words spoken by a male or female speaker and completed memory tests in which the stimuli were unstudied foil words and studied words spoken by either the same speaker at study, or the alternate speaker. On "general" test trials, participants were to determine whether each word was studied, regardless of the voice of the speaker, whereas on "specific" test trials, participants were to additionally distinguish between studied words that were spoken in the same voice or a different voice at study. Thus, on specific test trials, participants were explicitly required to attend to voice information in order to evaluate each test item. Anterior (right BA 10), dorsolateral prefrontal (right BA 46), and inferior frontal (bilateral BA 47/12) regions were more active during specific than during general trials. Activation in anterior and dorsolateral PFC was enhanced during specific test trials even in response to unstudied items, suggesting that activation in these regions was related to the differential processing of retrieval cues in the two tasks. In contrast, differences between specific and general test trials in inferior frontal regions (bilateral BA 47/12) were seen only for studied items, suggesting a role for these regions in post-retrieval monitoring processes. Results from this study are consistent with the idea that different PFC subregions implement distinct, but complementary processes that collectively support accurate episodic memory judgments.     

俯卧位通气对高海拔地区肺复张治疗无效急性呼吸窘迫综合征患者氧合的影响

目的 探讨俯卧位通气对高海拔地区肺复张术(RM)治疗无效急性呼吸窘迫综合征(ARDS)患者的治疗作用.方法 从海拔2260m的地区医院筛选RM治疗无效的41例ARDS患者[平均氧合指数( PaO2/FiO2)较RM前升高＜20％视为RM无效],依不同病因分为肺内源性ARDS组(ARDSp组)和肺外源性ARDS组(ARDSexp组),每组再按信封法随机分为俯卧位组和仰卧位组,即ARDSp俯卧位组(11例)、ARDSp仰卧位组(9例)、ARDSexp俯卧位组(10例)、ARDSexp仰卧位组(11例).在通气前及通气1、2、3、4h监测动脉血氧分压( PaO2)、PaO2/FiO2、静态顺应性(Cst)、气道阻力(Raw)的变化.结果 通气lh时,ARDSexp俯卧位组PaO2/FiO2( mm Hg,l mm Hg=0.133 kPa)即较通气前显著升高(157.4±40.6比129.3±48.7,P＜0.05),并随通气时间延长呈持续增高趋势,4h达峰值(219.1 ±41.1);且ARDSexp俯卧位组通气3h内PaO2/FiO2较其他3组显著增高,另3组间则差异无统计学意义.ARDSp俯卧位组、ARDSexp俯卧位组通气4h时PaO2/FiO2均较相应仰卧位组显著增高(208.8±39.7比127.4±47.1,219.1±41.1比124.9±50.8,均P＜0.05).4组通气前后Cst无显著改变,各组间差异也无统计学意义.ARDSp俯卧位组通气4h时Raw(cmH2O·L-1·s-1)较通气前显著降低(6.8±1.7比10.7±1.8,P＜0.05),且明显低于其他3组;其他3组各时间点Raw组内及组间比较差异均无统计学意义.结论 俯卧位通气作为ARDS机械通气重要策略之一,可以改善RM无效高原ARDS患者的氧合,为抢救患者赢得宝贵的时间.     

Digital imaging among medical facilities

The Department of Veterans Affairs (VA) in the USA operates a network of 172 medical centres which all utilize a hospital information system (HIS) which has been developed and is currently maintained by the VA. During the past several years, an image management and communication module has been developed, installed and clinically utilized at the Washington DC and Maryland VA Medical Centres. This image management and communication system, referred to as the decentralized hospital computer program (DHCP) imaging system, is fully integrated with a commercial picture archiving and communication system (PACS). The system is utilized to capture, archive, and display all images generated within the hospital including radiology, nuclear medicine, pathology, endoscopy, bronchoscopy, and dermatology, intraoperative photographs, ECG data, and a limited number of paper documents. The ultimate goal of the project is to have all patient text and image data available at any clinical workstation to any authorized user anywhere within the network of medical centres. Clinical requirements for an imaging workstation include ease of use, rapid and reliable access to the complete set of patient information, and images which are of acceptable quality to meet the requirements of the user and the subspecialty. Patient confidentiality and data security must be safeguarded at all times. Integration of the images with the remainder of the patient's database was found to be critical to the success of the project. The experience at the Washington and Maryland facilities suggests that an imaging system that is successfully integrated with a hospital information system can provide substantial clinical and economic benefits both within and among medical centres. Clinical acceptance and utilization of the system has been excellent, particularly in diagnostic radiology where DHCP Imaging has been interfaced to a commercial PAC system. Based upon this initial experience, the VA has begun to deploy the system throughout its large network of medical centres.     

Myocardial elastography at both high temporal and spatial resolution for the detection of infarcts

Myocardial elastography is a novel method for noninvasively assessing regional myocardial function, with the advantages of high spatial and temporal resolution and high signal-to-noise ratio (SNR). In this paper, in-vivo experiments were performed in anesthetized normal and infarcted mice (one day after left anterior descending coronary artery [LAD] ligation) using a high-resolution (30 MHz) ultrasound system (Vevo 770, VisualSonics Inc., Toronto, ON, Canada). Radiofrequency (RF) signals of the left ventricle (LV) in longitudinal (long-axis) view and the associated electrocardiogram (ECG) were simultaneously acquired. Using a retrospective ECG gating technique, 2-D full field-of-view RF frames were acquired at an extremely high frame rate (8 kHz) that resulted in high-quality incremental displacement and strain estimation of the myocardium. The incremental results were further accumulated to obtain the cumulative displacements and strains. Two-dimensional and M-mode displacement images and strain images (elastograms), as well as displacement and strain profiles as a function of time, were compared between normal and infarcted mice. Incremental results clearly depicted cardiac events including LV contraction, LV relaxation and isovolumetric phases in both normal and infarcted mice, and also evidently indicated reduced motion and deformation in the infarcted myocardium. The elastograms indicated that the infarcted regions underwent thinning during systole rather than thickening, as in the normal case. The cumulative elastograms were found to have higher elastographic SNR (SNR(e)) than the incremental elastograms (e.g., 10.6 vs. 4.7 in a normal myocardium, and 6.0 vs. 2.4 in an infarcted myocardium). Finally, preliminary statistical results from nine normal (m = 9) and seven infarcted (n = 7) mice indicated the capability of the cumulative strain in differentiating infracted from normal myocardia. In conclusion, myocardial elastography could provide regional strain information at simultaneously high temporal (>/=0.125 ms) and spatial ( approximately 55 microm) resolution as well as high precision ( approximately 0.05 microm displacement). This technique was thus capable of accurately characterizing normal myocardial function throughout an entire cardiac cycle, at the same high resolution, and detecting and localizing myocardial infarction in vivo.     

Clinical Pharmacokinetics of Morphine

Morphine, the most widely used mu-opioid analgesic for acute and chronic pain, is the standard against which new analgesics are measured. A thorough understanding of the pharmacokinetics of morphine is required in order to safely and effectively use this analgesic in a wide variety of patients with different levels of organ function. A MEDLINE search was conducted to identify literature published between 1966 and January 2002 relevant to the pharmacokinetics of morphine. These publications were reviewed and the literature summarized regarding unique and clinically important elements of morphine disposition relative to its parenteral administration (including intravenous, intramuscular, subcutaneous, epidural and intrathecal administration), absorption profile (immediate release, controlled release, and sublingual/buccal, and rectal administration), distribution, and its metabolism/ excretion. Special populations, including infants, elderly, and those with renal/liver failure, have a unique morphine pharmacokinetic profile that must be taken into account in order to maximize analgesic efficacy and reduce the risk of adverse events.