甲状腺实性结节的超声弹性成像定量参数分析

目的 探讨实时超声弹性成像定量参数分析在诊断甲状腺实性结节性质中的价值.方法分析112例(157个病灶)甲状腺实性结节患者的超声弹性图像,计算病灶与周围组织的应变率比值及其平均值,并通过受试者操作特点(ROC)曲线分析取得最合适的诊断甲状腺良恶性病灶临界值.所有病例均经手术及病理证实.结果 157个病灶中良性结节79个,应变率比值平均值为1.93±1.29;恶性病灶78个,应变率比值平均值为5.07±4.21,两者间差异有统计学意义(t=6.319,P<0.01).根据良恶性结节的应变率比值绘制ROC曲线,曲线下面积为0.861±0.031.通过ROC 曲线分析得出良恶性结节的弹性应变率比值临界点为2.96,其敏感度、特异度和准确性分别为73.1%(57/78)、88.6%(70/79)和80.9%(127/157).结论 实时超声弹性成像定量参数分析为甲状腺实性结节的良恶性鉴别诊断提供了一种新方法.     

声脉冲辐射力弹性成像鉴别甲状腺结节良恶性的价值

目的探讨声脉冲辐射力(ARFI)弹性成像在甲状腺局灶性病变良恶性鉴别诊断中的价值。方法应用ARFI弹性成像声触诊组织定量(VTQ)技术检测甲状腺结节120个,记录结节的横向剪切波速度(SWV),并计算每个结节与其周围甲状腺组织的SWV比值。结果甲状腺良性和恶性结节的SWV平均值分别为(2.28±0.84)m/s(范围:0.61～9.00m/s)和(5.04±2.78)m/s(范围:2.32～9.00m/s)(P=0.000)。甲状腺良恶性病灶的SWV值分布情况有显著性差别。良性和恶性结节的病灶SWV与周围甲状腺组织的SWV比值平均值分别为1.14±0.42(范围:0.31～2.59)和2.39±1.43(范围:0.89～6.16)(P=0.000)。甲状腺良恶性病灶SWV与周围组织的SWV比值分布情况有显著性差别。将病灶SWV值及病灶SWV与周围组织的SWV比值用于鉴别甲状腺结节的良恶性,受试者工作特征曲线(ROC曲线)的曲线下面积(AUC)分别为0.849及0.806。结论 ARFI可反映甲状腺结节的弹性特征,对甲状腺结节的良恶性鉴别诊断有一定的帮助。     

实时组织弹性成像在桥本甲状腺炎合并甲状腺结节鉴别中的临床应用

目的:应用实时组织弹性成像技术对合并甲状腺结节的桥本甲状腺炎(Hashimoto’s thyroiditis,HT)患者进行检测,鉴别其在诊断甲状腺良恶性结节中的临床价值。方法:选取HT合并甲状腺结节患者54例(共162个结节)。每例患者均经穿刺活检或术后病理证实结节良恶性。根据结节良恶性分为良性组和恶性组。对每例患者的甲状腺结节进行弹性图像评分,计算弹性应变率比值,并绘制良性及恶性结节的受试者工作特征(receiver operating characteristic,ROC)曲线。结果:54例HT患者共162个结节,其中,良性结节131个,恶性结节31个。HT合并良性结节、恶性结节的弹性图像分级为0~Ⅱ级、Ⅲ~Ⅳ级。应变率比值的均值分别为2.54±1.39、7.48±3.64。良性组与恶性组应变率比值的均值差异有统计学意义(t=12.78,P0.05)。以病理结果为"金标准",通过ROC曲线确定应变率比值的均值的诊断临界点为4.91,灵敏度、特异度、阳性似然比和阴性似然比分别为90.63%、81.25%、4.83和0.12。结论:实时组织弹性成像技术可以对HT合并结节的性质进行判定,有助于提高甲状腺良恶性结节诊断的准确率。     

超声弹性应变比值对甲状腺结节良恶性的鉴别诊断价值

目的探讨超声弹性应变比值(SR)对甲状腺结节良恶性的鉴别诊断价值。方法 97例甲状腺结节患者,其中良性65例,恶性32例,采用超声弹性成像技术测量周围组织与结节的SR,比较良性与恶性结节间SR的差异,通过建立受试者工作特性曲线(ROC)来评价SR诊断甲状腺良恶性结节的价值。结果 65例良性及32例恶性甲状腺结节的SR值分别为1.41±0.73及6.57±4.34,差异有统计学意义。应用ROC曲线评价SR诊断甲状腺恶性结节的曲线下面积为0.982,取SR阈值为2.73时,敏感度、特异度、准确性、阳性预测值及阴性预测值分别为96.88%、96.92%、96.91%、93.94%和98.44%。结论超声弹性参数SR对甲状腺结节的良恶性鉴别有较好的应用价值。     

实时超声弹性成像定量参数分析在甲状腺结节诊断中的初步应用

目的 探讨实时超声弹性成像定量参数分析在鉴别诊断甲状腺良恶性结节中的价值.方法 分析86例甲状腺结节患者的超声弹性图像,计算病灶与周围组织的应变比值(strain ratio),分别统计良恶性病灶的比值均数,并通过ROC曲线分析取得最合适的临界值.所有病例均经手术及病理证实.结果 良性结节的应变比值平均2.18,而恶性结节为8.48,两者差异有统计学意义(P<0.05).通过ROC曲线分析,取得最合适诊断临界点为3.3.结论 实时超声弹性成像定量分析为甲状腺结节的良恶性鉴别诊断提供了一种新的方法.     

应用ROC曲线评价超声弹性成像在甲状腺良恶性结节鉴别诊断中的应用价值

目的探讨超声弹性成像在甲状腺良恶性结节鉴别诊断中的应用价值。方法应用超声弹性成像技术对二维超声检查发现的61例81个甲状腺结节的弹性图像进行评分;按术后病理诊断分为良恶性组,行弹性图像对比分析,并绘制受试者工作特征曲线(ROC曲线),确定诊断界点。结果 61例81个甲状腺结节病理诊断良性66个(良性组),恶性15个(恶性组);良性组弹性图像评分多集中在0～2分(51/66,77.3%),恶性组弹性评分多集中在3～4分(13/15,86.7%),恶性组结节评分明显高于良性组,差异有统计学意义(Z=-3.778,P=0.000)。以弹性评分≥3分为鉴别甲状腺良恶性结节的诊断界点,则诊断灵敏度、特异度及准确性分别为86.7%,81.8%,79.0%;ROC曲线下面积为0.876。结论超声弹性成像有助于对甲状腺良恶性结节进行鉴别诊断,在临床诊断中具有较高的应用价值。     

甲状腺实性结节的声脉冲辐射力弹性成像诊断研究

目的 评估声脉冲辐射力弹性成像技术(ARFI)对甲状腺实性结节良恶性鉴别诊断价值.方法 对100例患者的118个实性结节行ARFI弹性成像声触诊组织成像(VTI)及声触诊组织定量(VTQ)两种技术检查,以VTI弹性分级≥IV级判断为恶性结节;VTQ中计算结节剪切波速度(SWV)平均值、结节周围非病灶组织平均值及两者的比值.结果 根据ROC曲线得出甲状腺良恶性结节SWV平均值及比值的最佳诊断界值分别为2.66m/s、1.21,曲线下面积(AUC)分别为0.780、0.762,敏感性、特异性、准确率分别为56%、89%、74%,69%、73%、71%;以VTI弹性分级≥IV级判断甲状腺实性结节良恶性具有显著性意义(P=0.000),其敏感性为78%,特异性为77%,准确率为77%.结论 ARFI技术定性及定量评价组织硬度,对甲状腺实性结节良恶性鉴别均有较高价值,两者结合应用对甲状腺实性结节的超声鉴别诊断有较大帮助.     

实时剪切波弹性成像在甲状腺实性结节良恶性鉴别诊断中的临床应用

目的 探讨实时剪切波弹性成像在甲状腺实性结节良恶性鉴别诊断中的应用价值.方法 应用实时剪切波弹性成像技术对83例患者共113个甲状腺实性结节测量杨氏模量值,与手术病理结果进行对照,绘制ROC曲线图,获得区分甲状腺结节良恶性的杨氏模量临界值.结果 ①良性组杨氏模量值为(23.57±9.35)kPa,恶性组为(43.73±19.82)kPa,两者差异有统计学意义(t =6.31,P=0.00).②通过ROC曲线确定良、恶性结节杨氏模量值的临界点为27.49 kPa,其敏感性为93.2％,特异性为81.2％,准确性为85.8％,ROC曲线下面积为0.91.结论 实时剪切波弹性成像技术可对甲状腺结节良恶性作出定量诊断,为鉴别甲状腺结节的良恶性提供了一种新的方法.     

超声实时组织弹性成像技术定量评价甲状腺肿块的应用价值

目的 探讨超声实时组织弹性成像技术定量评价甲状腺良恶性肿块的应用价值.方法 对73例甲状腺肿块患者共95个病灶,应用实时组织弹性成像技术获得肿块应变率与胸锁乳突肌弹性应变率比值,判断病灶的良恶性,并与术后病理结果进行对照,绘制ROC曲线图,获得区分甲状腺肿块良恶性应变率比值的临界值.结果 ①甲状腺肿块良性组弹性应变率比值为2.06 ±1.01,恶性组弹性应变率比值为5.05 ±2.23,两组间差异有统计学意义(P＜0.05).②甲状腺良恶性肿块弹性应变率比值的ROC曲线下面积为0.929,差异有统计学意义(P＜0.05).③通过ROC曲线确定良、恶性肿块弹性应率比值的临界点为3.17,其灵敏度、特异度、阳性预测值、阴性预测值分别为96.7%、90.8%、93.3%和96.9%.结论 超声实时组织弹性成像技术可以简便、无刨、定量地对甲状腺良、恶性肿块进行鉴别诊断.     

两种弹性定量方法评估良恶性乳腺实性肿块硬度的对比研究

目的对比分析声触诊组织量化(VTQ)和声触诊组织成像(VTI)联合Adobe Photoshop灰度定量两种弹性定量方法在鉴别诊断乳腺实性肿块良恶性中的应用价值。方法选取98例乳腺肿瘤患者(108个乳腺实性肿块),应用VTQ获得代表肿块中央局部硬度的剪切波速度(VS),同时应用VTI联合Adobe Photoshop灰度定量技术计算VTI弹性图中病灶整体灰度平均值,代表乳腺肿块整体硬度。与病理结果对照,分别比较良恶性乳腺肿块中央局部硬度和整体硬度的差异,获得最佳截断值,比较两个指标的诊断效能。结果恶性和良性乳腺肿块的局部硬度VS值分别为(6.96±2.50)m/s和(2.62±1.82)m/s,差异有统计学意义(P=0.000)。ROC曲线获得最佳截断值为2.78 m/s,以肿块中央局部硬度VS2.78 m/s诊断恶性乳腺肿块的敏感性、特异性及准确率分别为91.18%、88.64%及89.74%,与病理结果高度一致(校正χ2=0.125,P=0.724;Kappa=0.793,P=0.000)。恶性和良性乳腺肿块整体硬度灰度平均值分别为39.21±16.60和63.94±19.42,差异有统计学意义(P=0.000)。ROC曲线获得最佳截断值为50.75,以肿块整体硬度灰度平均值50.75诊断恶性乳腺肿块的敏感性、特异性及准确率分别为79.41%、77.27%及78.21%,与病理结果中度一致(校正χ2=0.235,P=0.628;Kappa=0.561,P=0.000)。结论 VTQ诊断效能高于VTI联合Adobe Photoshop灰度定量技术,但二者均有助于鉴别乳腺实性肿块性质。     

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.