剪切波弹性成像和γ-谷氨酰转肽酶/血小板比用于诊断慢性乙型肝炎患者肝纤维化

目的 探讨剪切波弹性成像（SWE）和γ-谷氨酰转肽酶/血小板比值（GPR）用于诊断慢性乙型肝炎（CHB）患者肝纤维化的应用价值。方法 选择116例CHB患者，在肝脏穿刺活检前行SWE检测及血常规及肝功能检验，记录肝脏硬度（LSM），计算GPR。根据Metavir评分系统将活检所示肝纤维化分为F0~F4共5期，分析Elast PQ和GPR与肝脏纤维化分期的相关性。绘制受试者工作特征（ROC）曲线，比较Elast PQ和GPR诊断CHB患者肝纤维化效能的差异，分析Elast PQ诊断丙氨酸氨基转移酶（ALT）≤ 2倍正常值上限（ULN）患者肝纤维化的价值。结果 Elast PQ和GPR与肝脏纤维化分期均呈正相关（r=0.94，P<0.01；r=0.92，P<0.01）。对于F1~F3期肝纤维化，Elast PQ的诊断效能优于GPR（Z=2.21，P=0.03；Z=2.16，P=0.03；Z=2.27，P=0.02）。Elast PQ对ALT ≤ 1×ULN患者的诊断效能优于其对1×ULN结论 Elast PQ和GPR对ALT ≤ 2×ULN的CHB患者早期肝纤维化分期具有较高价值，Elast PQ的诊断效能更好。     

慢性肝病患者剪切波弹性模量值的多因素回归分析

目的 分析慢性肝病患者肝实时二维剪切波弹性成像(SWE)模量值的相关因素及其独立预测因子。方法 收集慢性肝病患者142例,对所有病例均行SWE、肝穿刺活检及病理检查,获得肝炎症活动度G分级,肝纤维化S分期。同时记录临床及实验室相关指标,变量包括性别、年龄、体质量指数(BMI)、谷草转氨酶(AST)、谷丙转氨酶(ALT)、总胆红素(TB)、白蛋白(ALB)、谷氨酰转肽酶(GGT)、碱性磷酸酶(ALP)、血小板计数(PLT),凝血酶原时间(PT)、凝血酶原活动度(PT%)。分别与SWE肝弹性模量值作Spearman两两相关分析,筛选出具有统计学意义的变量进行多重线性回归分析,得出回归方程进行方差分析,评估方程的独立预测因子。结果 肝炎症活动度G分级(G)、肝纤维化S分期、年龄(age)、AST、ALT、TB、ALB、GGT、ALP、PLT、PT、PT%,与SWE弹性模量值具有相关性(P均<0.01)。拟合的回归模型:SWE=32.71+2.52G+0.18age－0.43ALB+0.01GGT－0.15PT%,方程调整R²=0.49(P<0.01)。结论 肝炎症活动度G分级和肝纤维化S分期与SWE模量值具有较高的相关性;肝炎症活动度G分级是其最主要的独立预测因子。     

动态增强磁共振定量参数评估儿童先天性胆总管囊肿致肝纤维化

目的 探讨动态增强磁共振（DCE-MRI）定量参数评估儿童先天性胆总管囊肿（CCC）所致肝纤维化的价值。方法 纳入33例CCC致肝纤维化患儿（病例组），以14例无肝肾疾患儿童为对照组。采集肝脏DCE-MRI后，拟合Tofts模型，获得参数K^trans、K_ep及V_e，观察不同肝纤维化分期定量参数差异及其相关性，以ROC曲线分析各参数诊断肝纤维化的AUC和最佳截界值。结果 K^trans、K_ep在不同纤维化亚组间差异均有统计学意义（P均<0.05），且随肝纤维化程度增加而下降（r=-0.764、-0.720，P均<0.05）；V_e在不同纤维化亚组中差异无统计学意义（P>0.05），与肝纤维化程度无明显相关（r=-0.249，P>0.05）。K^trans、K_e判别正常与肝纤维化、轻度与重度肝纤维化的AUC分别为0.949、0.748和0.933、0.731，截界值分别为0.239、0.186和1.814、1.663。结论 DCE-MRI定量灌注参数K^trans、K_ep对诊断儿童CCC致肝纤维化及其分期具有一定价值。     

红细胞体积分布宽度与血小板比值在慢性乙型肝炎患者肝纤维化评估中的临床价值

目的 探讨红细胞体积分布宽度(RDW)与血小板(PLT)比值(RPR)在慢性乙型肝炎(CHB)患者肝纤维化评估中的作用.方法 收集173例CHB患者作为病例组,评估其肝纤维化、肝硬化程度.收集同期的体检者作为健康对照组,比较两组血常规多项指标和生化指标(清蛋白、血脂、肝肾功能)的差异.比较CHB患者不同肝纤维化分期各纤维化指标及RPR的水平及诊断价值.结果 随着肝纤维化程度的加重,病例组患者RPR、Ⅳ型胶原、层粘连蛋白和透明质酸水平逐渐上升,且差异均有统计学意义(P<0.05).RPR对肝纤维化F2期诊断的AUC为0.704;对肝纤维化F3期诊断的AUC为0.792;对肝纤维化F4期诊断的AUC为0.818.结论 对于CHB患者,RPR对于肝细胞纤维化评估具有较好的诊断价值.RDW和PLT是医院中常见的经济、简单的检查方法,参考两者的比值可减少患者肝活检,可在未普及肝纤维化4项检查的情况下应用.     

剪切波点定量弹性成像技术对慢性乙型肝炎肝纤维化分期的诊断价值

目的 探讨剪切波点定量弹性成像（ElastPQ）技术测量肝组织硬度对诊断慢性乙型肝炎（CHB）肝纤维化分期的价值。方法 选取68例CHB患者为观察对象，24名健康体检者为对照，应用ElastPQ技术进行肝组织硬度检测，获得所有受试者的肝硬度值（ElastPQ值）。以肝穿刺活组织病理结果为金标准，绘制ElastPQ值诊断各肝纤维化分期的ROC曲线，分析其诊断效能。结果 不同分期肝纤维化ElastPQ值差异具有统计学意义（F=9.45，P<0.05），且ElastPQ值与肝纤维化程度呈正相关（r=0.672，P<0.001）。ElastPQ值诊断肝纤维化分期>S0期、>S1-2期、>S3期的界值分别为6.24 kPa、9.20 kPa、15.96 kPa，相应的AUC分别为0.904、0.855、0.772，敏感度分别为93.2%、78.0%、76.3%，特异度分别为100%、89.7%、76.9%。结论 ElastPQ技术可有效评估肝组织弹性硬度，对诊断肝纤维化分期具有重要的临床价值。     

比较MR弹性成像及动态增强成像评价肝硬化食管胃底静脉曲张

目的 比较MR弹性成像（MRE）及动态增强成像（DCE-MRI）诊断肝硬化食管胃底静脉曲张（GEV）的价值。方法 收集接受MRE及DCE-MRI检查的肝硬化患者59例,记录血小板计数（PLT）,测量肝弹性值（HS）、脾弹性值（SS）和MR增强视觉分级相关指标;以内镜结果为金标准,采用ROC曲线下面积（AUC）比较相关指标诊断GEV的价值。结果 PLT、HS、SS及MR增强视觉分级与肝硬化GEV分级具有相关性（r_s=-0.317、0.436、0.682、0.703,P均<0.05）。诊断有无GEV时,SS的AUC略高于MR增强视觉分级、HS、PLT （AUC分别为0.880、0.795、0.744、0.635）,其中SS与PLT的AUC差异有统计学意义（P=0.002）;诊断中重度GEV时,MR增强视觉分级的AUC略高于SS、HS、PLT （AUC分别为0.893、0.816、0.713、0.665）,其中MR增强视觉分级与HS、PLT的AUC差异有统计学意义（P=0.018、0.002）。联合SS及MR增强视觉分级,鉴别诊断有无GEV及中重度GEV的敏感度分别为94.16%、96.83%。结论 MRE可有效预测GEV及其严重程度,与DCE-MRI效果相当。     

中国版甲状腺影像报告和数据系统(C-TIRADS)联合结节内部及周围腺体硬度鉴别甲状腺良、恶性结节

目的 评估中国版甲状腺影像报告和数据系统（C-TIRADS）联合结节内部及周围腺体硬度鉴别甲状腺良、恶性结节的价值。方法 回顾性分析117例经细针抽吸细胞学检查（FNAC）和/或手术病理确诊甲状腺结节患者的常规超声及超声剪切波弹性成像（SWE）资料,按照C-TIRADS对结节进行分类;基于SWE技术测量结节及其周围2 mm腺体的SWE参数,包括甲状腺结节（E）及结节周围腺体（Eshell）杨氏模量值[最大值（E_max/Eshell_max）、平均值（E_mean/Eshell_mean）、最小值（E_min/Eshell_min）及标准差（E_SD/Eshell_SD）]。绘制受试者工作特征（ROC）曲线,计算曲线下面积（AUC）,评估C-TIRADS、SWE及二者联合鉴别甲状腺良、恶性结节的效能。结果 共纳入117例共117个甲状腺结节,包括良性结节50个、恶性结节67个。甲状腺恶性结节各SWE参数均高于良性结节（P均<0.001）。C-TIRADS鉴别甲状腺良、恶性结节的AUC为0.736,敏感度为79.10%、特异度为68.00%、准确率为74.36%;E_max、E_mean、E_min及E_SD的AUC分别是0.816、0.752、0.664及0.705,以E_max的AUC最高;Eshell_max、Eshell_mean、Eshell_min及Eshell_SD的AUC分别为0.834、0.804、0.693及0.697,以Eshell_max的AUC最高,而与E_max差异无统计学意义（Z=1.044,P=0.297）。C-TIRADS+E_max和C-TIRADS+Eshell_max的AUC分别为0.835和0.843,其间差异无统计学意义（Z=0.574,P=0.566）但均高于C-TIRADS（AUC=0.736,Z=2.510、2.230,P均<0.05）,二者诊断特异度及准确率均高于C-TIRADS（P均<0.05）。结论 C-TIRADS联合结节内部及其周围腺体硬度可有效鉴别良、恶性甲状腺结节,显著提高C-TIRDAS诊断效能。     

磁共振T1 mapping、T2 mapping评估大鼠肝纤维化和肝脂肪变性

目的 采用磁共振T1 mapping、T2 mapping评估大鼠肝纤维化和肝脂肪变性，观察其应用价值。方法 将80只大鼠随机分成实验组（n=70）对照组（n=10）， 分别于背部注射四氯化碳橄榄油溶液及生理盐水，制作大鼠肝纤维化模型。于注药后第4、6、8、10和12周，分别随机选取实验组14只和对照组2只大鼠采集MRI，测量肝实质T1值和T2值，并行组织病理检查。根据病理结果将大鼠肝纤维化划分为S₀~S₄期，脂肪变性划分为F₀~F₄度，比较肝纤维化各期T1值和T2值，分析其与肝纤维化及肝脂肪变性相关性。结果 S₀期大鼠肝脏T1值和T2值与肝纤维化各期差异有统计学意义（P均<0.05），S₁期[（402.01±57.14）ms]肝实质T1值较S₃期[（514.83±87.10）ms]和S₄期[（518.72±36.50）ms]短（P均<0.05），S₂期[（417.49±47.00）ms]肝实质T1值较S₄期短（P<0.05）；S₁期[（65.12±9.46）ms]肝实质T2值较S₄期[（55.33±7.30）ms]略延长（P<0.05）。T1值与肝纤维化程度呈正相关（r=0.68，P<0.01），T2值与脂肪变性程度呈正相关（r=0.72，P<0.01）。结论 磁共振T1 mapping可无创评估大鼠肝纤维化，T2 mapping可无创评估大鼠肝脂肪变性，有望为临床诊断肝纤维化和肝脂肪变性提供新的影像学方法。     

剪切波弹性成像联合CEUS校正乳腺影像报告和数据系统3~5类乳腺病变

目的 探讨剪切波弹性成像（SWE）联合CEUS在校正乳腺影像报告和数据系统（BI-RADS）3~5类乳腺肿瘤中的应用价值。方法 收集50例乳腺病变患者（57个病灶）,其中良性病灶28个,恶性29个。对所有病灶术前行常规超声、SWE和CEUS检查,以常规超声进行BI-RADS分类,并采用SWE、CEUS及SWE联合CEUS对BI-RADS分类进行校正。以病理结果为金标准,计算常规超声、SWE、CEUS及SWE联合CEUS诊断乳腺良恶性病灶的敏感度、特异度和诊断正确率。结果 SWE参数最大杨氏模量值（E_max）诊断乳腺良恶性病灶的临界值为87.2 kPa,CEUS的临界值为8.5分,SWE联合CEUS的多因素Logistic回归模型为Y（P）=-18.785+0.161X₁+11.822X₂,X₁为E_max,X₂为增强后病灶大小改变。SWE联合CEUS将11个病灶正确降为3级,4个病灶误诊;SWE联合CEUS诊断乳腺良恶性病灶的敏感度、特异度和诊断正确率分别为100%（29/29）、85.71%（24/28）和92.98%（53/57）。结论 SWE联合CEUS对BI-RADS 3~5类乳腺病灶具有良好的校正作用,可提高超声诊断正确率。     

实时剪切波弹性成像调整圆形Q-Box法与手动描绘Q-Box法鉴别诊断乳腺良恶性病变

目的 比较实时剪切波弹性成像（SWE）技术探讨调整圆形Q-Box法和手动描绘Q-Box法鉴别诊断乳腺良恶性病变的价值。方法 选取经SWE检查并经病理证实的乳腺肿物患者133例,共152个病灶,其中良性病灶115个,恶性病灶37个。分别采用调整圆形Q-Box法和手动描绘Q-Box法选取ROI,测量弹性模量平均值（E_mean）、弹性最大值（E_max）和弹性模量离散度值（SD）,并进行统计学分析。结果 两种方法测量恶性病灶的E_mean、E_max、SD均高于良性病灶（P均<0.05）。两种方法测量所有病灶E_mean、E_max、SD的差异均无统计学意义（P均>0.05）。两种方法测量E_mean、E_max、SD的AUC差异均无统计学意义（P均>0.05）。调整圆形Q-Box法测量E_mean的AUC较SD和E_max的AUC小（P均<0.05）,手动描绘Q-Box法测量E_mean的AUC较SD的AUC小（P<0.05）,余相同测量方法测量不同弹性模量的AUC两两比较,差异均无统计学意义（P均>0.05）。结论 调整圆形Q-Box法鉴别诊断乳腺良恶性病变的诊断效能与手动描绘Q-Box法相似,E_max与SD诊断效能相似。     

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.