超声观察高原日光照射对正常人皮肤厚度及硬度的影响

目的 探讨高频超声及剪切波弹性成像（SWE）评估高原日光照射对皮肤厚度及硬度的影响。方法 招募30名高原地区（高原组）、48名非高原地区（非高原组）志愿者,以高频超声及SWE测量右侧中指、右侧前臂、前胸壁及腹壁4个部位皮肤厚度及皮肤硬度。比较2组间4个部位皮肤厚度及硬度差异;选取皮肤厚度及弹性值差异有统计学意义的参数,行诊断性试验,并绘制ROC曲线。结果 高原组右侧中指皮肤厚度、最大弹性值（E_max）、平均弹性值（E_mean）、最小弹性值（E_min）及弹性值标准差（Esd）,右侧前臂及前胸壁皮肤E_max、E_mean、E_min,腹壁皮肤E_max、E_mean、E_min、Esd均大于非高原组（P均<0.05）;前胸壁及腹壁皮肤厚度小于非高原组（P均<0.05）。根据腹壁皮肤E_max、E_mean及E_min诊断高原地区皮肤的ROC曲线AUC均>0.95。以腹壁皮肤E_max=13.30 kPa、E_mean=12.45 kPa、E_min=11.50 kPa为界值,诊断高原地区皮肤的敏感度均为100%,特异度分别为85.40%、87.50%及85.40%。结论 高原日光照射会导致皮肤厚度改变和皮肤硬度增加;腹壁皮肤弹性值E_max、E_mean及E_min的诊断效能最高。     

常规超声联合二维剪切波弹性成像评价2型糖尿病涎腺异常

目的 观察常规超声(二维超声、彩色多普勒超声)联合二维剪切波弹性成像(2D-SWE)评价2型糖尿病(T2DM)患者涎腺异常的价值。方法 将65例T2DM患者分为A组(病程＜10年,n=30)和B组(病程≥10年,n=35);另以同期30名健康志愿者为对照组。对比观察3组涎腺(腮腺、下颌下腺)超声评分、腺体面积、血流信号及杨氏模量值(E),包括单侧腮腺及下颌下腺E最大值(E_max)、平均值(E_mean)、最小值(E_min)及两侧平均值E_总max、E_总mean及E_总min;分析常规超声联合2D-SWE评价T2DM涎腺异常的价值。结果 3组涎腺超声评分、面积及血流信号数目差异均有统计学意义(P均＜0.05);A、B组腮腺及下颌下腺超声评分、面积及涎腺总超声评分均大于对照组而血流信号数目均小于对照组(P均＜0.05),且A组腮腺及下颌下腺面积均小于B组(P均＜0.05)。3组间涎腺E_总max、E_总mean及E_总min差异均有统计学意义(P均＜0.05);其中A、B组涎腺E_总max、E_总mean及E_总min均高于对照组(P均＜0.05),且A组涎腺E_总max、E_总mean及E_总min均低于B组(P均＜0.05)。结论 常规超声联合2D-SWE可评价T2DM患者涎腺异常改变,包括腺体面积、超声评分及硬度均增加及血流信号减少。     

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。     

经会阴盆底超声联合剪切波弹性成像测量肛提肌诊断女性压力性尿失禁

目的 观察经会阴盆底超声联合肛提肌（LAM）剪切波弹性成像（SWE）诊断女性压力性尿失禁（SI）的价值。方法 对32例SI患者（SI组）和34名已育健康女性（对照组）行经会阴盆底常规超声及SWE检查,获取静息状态及最大瓦尔萨尔瓦动作下LAM弹性模量最大值（E_max）和平均值（E_mean）及其最大值的差值（△E_max）和平均值的差值（△E_mean）;行Logistic回归分析,绘制受试者工作特征（ROC）曲线,观察LAM各弹性模量值诊断SI的效能。结果 SI组与对照组间月经状况、尿道漏斗形成情况、BND及LAM厚度差异均有统计学意义（P均<0.05）。SI组LAM的△E_max和△E_mean均小于对照组（P均<0.05）。静息状态下,SI组与对照组LAM的E_max和E_mean差异均无统计学意义（P均>0.05）;最大瓦尔萨尔瓦动作下,SI组LAM的E_max和E_mean均小于对照组（P均<0.05）,且SI组及对照组LAM的E_max和E_mean均大于静息状态下（P均<0.05）。以21.40 kPa为截断值,△E_max诊断SI的敏感度和特异度分别为80.40%和71.90%;以18.80 kPa为截断值,△E_mean的敏感度和特异度分别为85.60%和85.00%,均大于△E_max（P均<0.05）。尿道漏斗形成情况、BND和△E_mean是SI的独立危险因素（P均<0.05）。结论 经会阴盆底超声联合SWE 测量LAM有助于诊断女性SI;△E_mean<18.80 kPa可提示SI。     

实时剪切波弹性成像技术鉴别诊断肺良恶性周围型肿块

目的 探讨实时剪切波弹性成像（SWE）技术鉴别诊断肺部良恶性周围型肿块的价值。方法 采用SWE技术测量112例周围型肺部肿块患者的杨氏模量值,分析良恶性组及恶性病变不同病理类型亚组间的杨氏模量最大值（E_max）和平均值（E_mean）的差异。以病理结果为金标准,绘制ROC曲线获得其鉴别诊断良恶性肿块的效能。结果 周围型肺部肿块良恶性组间E_max及E_mean差异均有统计学意义（t=－2.78、－3.28,P均<0.01）,恶性组不同病理类型亚组间E_max及E_mean差异均无统计学意义（P均>0.05）。E_max和E_mean鉴别诊断肺良恶性肿块的阈值分别为10.35 kPa和5.85 kPa,AUC分别为0.74（P=0.003）、0.81（P=0.001）,敏感度、特异度、阳性预测值、阴性预测值分别为74.36%、72.22%、85.29%、57.52%和81.58%、80.78%、89.57%和67.67%。结论 SWE技术可用于评估周围型肺部肿块的弹性特征,为鉴别肺部良恶性周围型肿块提供了重要的影像学手段。     

不同ROI和弹性模量值对剪切波弹性成像诊断颈部良恶性淋巴结效能的影响

目的 探讨剪切波弹性成像（SWE）中,不同ROI和弹性模量值的选择对诊断颈部良恶性淋巴结的影响。方法 选取经穿刺活检或手术病理证实的143枚颈部肿大淋巴结,于术前行常规超声及SWE检查,设置3种不同ROI：直径2 mm的小圆形ROI（ROI-1）、不超出淋巴结边缘的最大切圆ROI（ROI-2）及手动勾勒整个淋巴结边缘的ROI（ROI-3）,均包含淋巴结的最硬区域,分别测量最大弹性值（E_max）、平均弹性值（E_mean）和弹性标准差（SD）并进行对比分析,构建ROC曲线获得各弹性值诊断颈部良恶性淋巴结的AUC,并进行比较。结果 恶性淋巴结3种ROI测量的E_max、E_mean和SD均高于良性淋巴结（P均<0.001）。3种ROI测量的良性淋巴结、恶性淋巴结及总淋巴结E_max总体差异无统计学意义（P均>0.05）,E_mean和SD总体差异均有统计学意义（P均<0.001）。ROC曲线结果显示,3种ROI测量的E_max诊断良恶性淋巴结的AUC差异均无统计学意义（P均>0.05）,ROI-1测量的E_mean的AUC高于ROI-2和ROI-3（P均<0.05）,SD低于ROI-2和ROI-3（P均<0.05）,而后两者比较差异无统计学意义（P均>0.05）。结论 SWE能够对颈部良恶性淋巴结进行鉴别,但其诊断效能随ROI及弹性模量值的选择而不同。选择较小ROI时,建议使用E_max和E_mean;选择较大ROI时,建议使用E_max和SD。     

剪切波弹性成像观察糖尿病周围神经病变患者胫神经

目的 探讨剪切波弹性成像（SWE）技术评价糖尿病周围神经病变（DPN）患者胫神经改变的价值。方法 选取30例临床诊断为2型糖尿病伴周围神经病变患者、30例2型糖尿病不伴周围神经病变患者及30名健康志愿者（对照组），应用二维超声及SWE测量并比较3组双下肢远端胫神经横截面积（CSA）及弹性模量均值（E_mean）。分析2型糖尿病患者胫神经CSA、运动神经传导速度（MCV）及DPN （+）组患者疼痛视觉模拟量表（VAS）评分与E_mean的相关性。绘制E_mean诊断DPN的ROC曲线。结果 3组间胫神经CSA、E_mean总体差异有统计学意义（P均<0.01），两两比较差异均有统计学意义（P均<0.01）。2型糖尿病患者胫神经CSA与E_mean呈正相关（r=0.64，P<0.05），胫神经MCV与E_mean呈负相关（r=－0.70，P<0.05）；DPN （+）组患者VAS与E_mean呈正相关（r=0.82，P<0.05）。胫神经E_mean诊断2型糖尿病患者DPN最佳截断值为47.4 kPa，敏感度为94.2%，特异度为80.0%。结论 2型糖尿病患者胫神经硬度增加；弹性模量值可作为诊断DPN的参考指标。     

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。     

剪切波弹性成像技术定量评价亚临床性甲状腺功能减退症患者颈动脉弹性

目的 观察剪切波弹性成像（SWE）技术定量评价亚临床性甲状腺功能减退症（SCH）患者颈动脉弹性的价值,并与射频超声技术进行对比。方法 纳入84例SCH患者（观察组）及82名健康志愿者（对照组）,以射频超声技术获取双侧颈动脉内-中膜厚度（IMT）、膨胀系数（DC）、顺应系数（CC）、α系数、β系数及脉搏波传导速度（PWV）,以SWE技术测量平均、最大及最小弹性模量（ME_mean、ME_max、ME_min）,并比较各参数组间差异。采用线性回归评价各射频超声参数与ME_mean间相关性。绘制受试者工作特征（ROC）曲线,计算曲线下面积（AUC）,评价ME_mean诊断SCH患者动脉弹性改变的效能。结果 观察组DC及CC均明显低于对照组（P均<0.05）,α系数、β系数、PWV、ME_mean及ME_max均明显高于对照组（P均<0.05）。α系数、β系数、PWV与ME_mean均呈正相关（r=0.453、0.521、0.717,P均<0.05）。ME_mean预测SCH患者动脉弹性改变的AUC为0.822,敏感度为76.2%,特异度为63.8%。结论 SWE技术可用于评价SCH患者颈动脉弹性改变。     

声触诊组织量化成像联合超声造影鉴别诊断TI-RADS 4类良恶性甲状腺结节

目的 探讨声触诊组织量化成像（VTIQ）联合超声造影（CEUS）鉴别诊断TI-RADS 4类甲状腺良恶性结节的价值。方法 对经手术切除及术后病理证实的86例TI-RADS 4类甲状腺结节患者的98个结节（以45个良性结节为良性组，53个恶性结节为恶性组）于术前行VTIQ及CEUS检查，获取结节剪切波速度最大值（SWV_max）、最小值（SWV_min）、平均值（SWV_mean）、病灶最大值与周围正常组织的比值（SWV_ratio）及CEUS特征，建立VTIQ联合CEUS的Logistic回归模型；以AUC比较VTIQ、CEUS及二者联合回归模型对TI-RADS 4类良恶性甲状腺结节的鉴别诊断效能。结果 恶性组SWV_max、SWV_min、SWV_mean、SWV_ratio值均高于良性组（P均<0.05）。CEUS强化程度、强化均匀度、强化方式、环状增强、消退方式组间差异均有统计学意义（P均<0.05）。SWV_mean（>2.96 m/s）、强化程度（低增强）是诊断TI-RADS 4类恶性甲状腺结节的重要指标（P均<0.05）。SWV_mean、CEUS及Logistic回归模型诊断TI-RADS 4类甲状腺良恶性结节的AUC分别为0.862、0.835和0.933。结论 VTIQ及CEUS均可鉴别TI-RADS 4类甲状腺良恶性结节，二者联合可明显提高诊断效能。     

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.     

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.     

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.