磁敏感加权成像观察健康人群脑内铁含量

目的 用3.0T MR磁敏感加权成像(SWI)序列分析正常人脑深部核团内铁的分布特点.方法 48名正常人按年龄分为青年组(14～44岁)、中年组(45～59岁)和老年组(60岁以上).采用3.0T MR SWI序列对被检测者进行扫描.使用SPIN软件测量脑深部灰质核团内相位值,以单因素方差分析分析随年龄增长脑内深部灰质核团(齿状核、红核、黑质、丘脑、苍白球、壳核及尾状核头)铁的分布特点.结果 正常人脑内深部灰质核团(齿状核、红核、苍白球及壳核)的相位值变化与年龄呈负相关(r值分别为-0.453,-0.375,-0.353和-0.287);齿状核的平均相位值在中年组与老年组之间差异有统计学意义(P=0.012);齿状核、红核、苍白球及壳核的平均相位值在青年组与老年组之间差异亦有统计学意义(P均<0.05);不同部位灰质核团内铁的含量不同(P<0.05),其中红核含量最高.结论 铁在正常人脑深部灰质核团内分布不均匀;脑深部核团内铁的含量随年龄增长而变化,其中红核在老年组的平均相位值最低,即铁的含量最高.     

脑铁,I2弛豫时间和年龄的相关性研究

目的：研究脑铁、Ｔ２弛豫时间随年龄变化的规律和脑铁Ｔ２弛豫时间相关性。材料与方法：１５例尸体脑除外脑外伤、脑出血,脑梗塞,脑肿瘤和神经,精神系统疾病。分别测量不同区域灰质核闭和白质区Ｔ２弛豫时间和铁含量,绘出其随年龄变化的散点图,并进行脑铁、Ｔ２弛豫时间相关回归分析。     

磁敏感加权成像评价正常人大脑灰质核团铁含量

目的 应用磁敏感加权成像(SWI)技术相对定量分析不同年龄段的正常人脑深部灰质核团(包括黑质、红核、苍白球、壳核、尾状核)的脑铁含量的变化规律.方法 将171名健康志愿者按年龄分为5组:20～29岁、30～39岁、40～49岁、50～59岁、60～69岁,行头部SWI扫描并测量黑质、红核、苍白球、壳、尾状核头部的SWI信号值,分析各部位SWI信号值随年龄的变化规律.结果 不同年龄阶段所测量得到的尾状核头、壳核、苍白球、黑质、红核SWI信号值之间差异有统计学意义(P＜0.001),并按一定规律变化.尾状核、苍白球SWI信号值于20～39岁变化基本平稳,于40岁后随年龄的增长诸深部灰质核团SWI信号值快速下降(以红核及壳核为著).黑质、红核、壳核、尾状核头SWI信号值均与年龄呈明显负相关(r黑质=-0.759,r红核=-0.875,r壳核=-0.880,r尾状核头=-0.524,P＜0.001);苍白球SWI信号值与年龄存在弱相关(r=-0.211,P=0.042).结论 SWI信号值可以反映脑铁分布区域性和随年龄变化的规律.     

少见原因的脑内灰质核团异常信号的MRI 诊断

目的：描述脑内灰质核团铁、铜、锰和钙沉积的MRI表现,结合文献讨论其发生机制及其病理改变。方法：回顾性分析Hallervorden-Spatz病、Wilson病、肝脑变性以及各种原因引起的钙在脑内灰质核团沉积的病例共38例的MRI表现。结果：Hallervorden-Spatz病表现为双侧苍白球和黑质T2WI明显的低信号,并可见苍白球的前内侧对称出现的点状高信号（虎眼征）;Wilson病4例均表现为双侧壳核、中脑出现对称性的T2WI高信号,其中1例还可见双侧苍白球对称的T2WI低信号,肝脑变性表现为双侧苍白球（27／29）,壳核（6／29）,垂体前叶（13／29）,中脑红核周围（18／29）等部位出现高信号;特发性钙化所致钙在脑内灰质核团沉积表现为基底节、丘脑、齿状核对称出现的等和短T1信号。结论：脑内灰质核团的异常信号有其特定的病因学和病理学基础及相应的MRI表现,结合临床表现及实验室检查,可以做出正确的诊断。     

3.0T磁共振R2*值评价足月出生婴儿脑深部灰质核团年龄相关性铁沉积

目的 采用3.0T MR R2^*值观察婴儿脑深部灰质核团铁沉积与周龄的关系。方法 纳入婴儿53名,校正周龄(PMA)37~92周。采用GE 3.0T磁共振扫描仪进行增强T2^*加权血管成像(ESWAN)序列扫描,测量脑内双侧深部灰质核团(尾状核、壳核、苍白球、丘脑、红核和黑质)的R2^*值。对各部位R2^*值与脑铁含量进行相关分析,并分析R2^*值与PMA的关系。结果 婴儿期脑深部灰质核团R2^*值与脑铁含量均呈正相关(P均<0.001)。尾状核、壳核、苍白球、丘脑、红核和黑质的R2^*值与PMA均呈正相关(r=0.865、0.818、0.893、0.844、0.742和0.834,P均<0.001)。结论 婴儿期脑深部灰质核团的R2^*值随周龄增大逐渐增加,其可反映局部脑铁沉积随周龄的增加。     

3.0T磁共振脑深部核团T2信号值与脑铁浓度相关关系研究

目的：研究3.0 Tesla磁共振成像正常人脑深部灰质核团（主要包括红核、黑质、苍白球、壳核、尾状核头）T2信号值与局部脑组织非色素性铁浓度的相关关系。方法：收集2004年12月～2005年5月在北京天坛医院行头颅核磁共振检查正常人T₂WI 1192例，其中男689例，女503例，年龄1～87岁。将年龄按5年分组，共分17组。使用Efilm workstation 2.0图形工作站测量T₂WI脑深部核团和额叶皮层T2信号值，并计算脑深部核团相对额叶皮层比值R。结果：红核、黑质、苍白球、壳核R值与相应局部铁估计浓度存在直线负相关（红核P=0.001，r=-0.748；黑质P<0.001，r=-0.863；苍白球P<0.001，r=-0.965；壳核P<0.001，r=-0.816）。尾状核头部R值与铁估计值不存在直线相关（P=0.336>0.05）。结论：红核、黑质、苍白球、壳核R值可半定量反应相应部位脑组织内非色素性铁含量。     

复发-缓解型多发性硬化与复发型视神经脊髓炎脑深部灰质核团铁沉积的ESWAN对比定量分析

目的用3.0T MR 3D增强型T2*加权血管成像(ESWAN)相位图测量复发-缓解型多发性硬化(RRMS)与复发型视神经脊髓炎(RNMO)患者脑深部灰质核团的铁含量。方法选取RRMS患者50例(RRMS组)、RNMO患者50例(RNMO组)和年龄、性别相匹配的50名健康志愿者(对照组)行常规MR ESWAN扫描。以上3组分别分为20～39岁和40～59岁两个亚组,测量双侧苍白球(GP)、壳核(PUT)、尾状核头(HCN)、丘脑(THA)、黑质(SN)、红核(RN)及齿状核(DN)的平均相位值(MPVs),比较3个研究组间上述核团MPV在同年龄亚组间的差异。结果 RRMS患者20～39岁组双侧SN与同年龄对照组(左:t=-5.04,P<0.01;右:t=-2.82,P=0.02)和RNMO组(左:t=-4.79,P<0.01;右:t=-3.27,P=0.01)差异有统计学意义(P<0.05);同年龄RNMO患者脑深部核团MPVs均低于对照组,但差异均无统计学意义(P>0.05)。RRMS患者双侧HCN(左:r=-0.42,P=0.01;右:r=-0.43,P=0.01)和双侧DN(左:r=-0.42,P=0.02;右:r=-0.36,P=0.04)的MPV与病程呈负相关,但其扩展残疾状态量表评分与脑深部核团MPV未见明显相关性(P>0.05);RNMO患者脑深部各核团MPV与病程之间亦未见明显相关性(P>0.05)。结论 ESWAN相位图可量化评价脑铁含量;探讨上述两种病变深部灰质核团铁沉积的变化有助于理解脑深部灰质核团的病理改变。     

3.0T磁共振正常人脑深部核团T2信号与年龄的关系研究

目的研究3.0T磁共振成像正常人脑深部灰质核团(主要包括齿状核、红核、黑质、丘脑、苍白球、壳核、尾状核)T2信号值与年龄的相关关系。方法收集北京天坛医院正常人头部T2加权图像1192份(男689例,女503例),年龄范围为1~87岁,按5年分组,共17组。使用Efilm workstation 2.0工作站测量脑深部核团和额叶皮层T2WI信号值,计算其相对值R。结果正常人R值的不同主要取决于年龄组和脑深部核团的部位(P值均<0.01,决定系数=0.946);且红核、黑质、丘脑、苍白球、壳核、尾状核的R值(齿状核除外)与年龄组存在三次曲线方程关系[R=b0 b1x b2x2 b3x3,x表示年龄组(取值范围1~17),b0、b1、b2、b3分别是三次曲线方程常数项、一次系数、二次系数及三次系数,决定系数分别为0.646、0.847、0.856、0.911、0.873、0.778]。结论脑深部灰质核团铁分布不均匀,并且随年龄变化而变化。在所观察1~87岁年龄范围内,黑质、红核、苍白球、齿状核含铁量高,壳核、丘脑相对较少,尾状核最少。     

正常人脑壳核苍白球MRI T2信号变化规律（兼析Shy－Drager综合征壳核短T2信号）

本文对100例不同年龄正常脑MRI壳核，苍白球进行T2信号之观测，并对20例经Perl‘s铁反应染色相应部位之脑标本测定光密度，结合标本MRI与病理对照研究正常脑壳核，苍白球T2信号变化规律，同时对Shy-Drager综合征患者壳核短T2信号进行探讨，结果提示：壳核，苍白球T2信号之变化与铁沉积有关，并与年龄增长具有相关性，但二者变化曲线不同，并提示中枢神经系统变性病如Shy-Drager综合征可能是一种有价值的信号。     

磁敏感加权成像纵向观察复发-缓解型多发性硬化患者脑深部灰质核团铁沉积

目的利用3.0T MR 3D磁敏感加权成像(ESWAN)技术纵向观察复发-缓解型多发性硬化(RRMS)患者脑深部灰质核团铁沉积的动态变化及其与临床的相关性。方法选取RRMS患者30例,间隔2年进行2次ESWAN及常规MR检查。结合轴位及矢状位T2FLAIR图像,观察病灶的变化,并将其分为病灶增加组(n=15)、无变化组(n=9)和病灶减少组(n=6)。测量脑深部灰质核团的平均相位值(MPVs),比较ROI内铁含量的变化及与临床的相关性。结果与第1次相比,第2次检查结果中,除丘脑的相位值无明显变化外,其余各核团的相位值均降低,以黑质的变化最为显著(t=2.92,P=0.007)。病灶增加组及无变化组各核团的相位值均减低,病灶增加组各核团相位值降低幅度相对较大,其中以黑质的相位值降低最明显(t=5.40,P=0.001)。在病灶减少组,除齿状核的相位值降低外,其余核团的相位值均增加。在复发次数<2次的患者中,各核团的相位值变化均无统计学意义(P>0.05);而在复发次数≥2次的患者中,除丘脑(P=0.212)、苍白球(P=0.891)外,其余各核团的相位值变化均有统计学意义(P<0.05)。前、后2次EDSS评分之差与各核团相位值的变化之间均无相关性(P>0.05);除丘脑(r=0.332,P=0.073)外,病灶负荷与其余各核团相位值的变化间均明显相关(P<0.05)。结论 RRMS患者丘脑的铁含量相对稳定,其余深部灰质核团的铁含量变化与病灶的负荷相关。     

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.     

Guns and Knives in New Mexico: Patterns of Penetrating Trauma, 1978–1993

Objective: To identify patterns of nonfatal and fatal penetrating trauma among children and adults in New Mexico using ED and medical examiner data.
Methods: The authors retrospectively sampled in 5-year intervals all victims of penetrating trauma who presented to either the state Level-1 trauma center or the state medical examiner from a 16-year period (1978–1993). Rates of nonfatal and fatal firearm and stabbing injury were compared for children and adults.
Results: Rates of nonfatal injury were similar (firearm, 34.3 per 100,000 person-years; stabbing, 35.1). However, rates of fatal injury were significantly different (firearm, 21.9; stabbing, 2.7; relative risk: 8.2; 95% confidence interval: 5.4, 12.5). From 1978 to 1993, nonfatal injury rates increased for children (p = 0.0043) and adults (p < 0.0001), while fatal penetrating injury remained constant. The increase in nonfatal injury in children resulted from increased firearm injury rates. In adults, both stabbing and firearm nonfatal injury rates increased.
Conclusions: Nonfatal injury data suggest that nonfatal violence has increased; fatal injury data suggest that violent death rates have remained constant. Injury patterns vary by age, mechanism of trauma, and data source. These results suggest that ED and medical examiner data differ and that both are needed to guide injury prevention programs.