CT灌注成像评估单侧大脑中动脉狭窄患者脑血流动力学和血管成形术及支架置入术疗效

目的 CT灌注(CTP)成像评价单侧大脑中动脉(MCA)狭窄患者脑血流动力学变化和血管成形术及支架置入术(PTAS)效果。方法 选取单侧MCA狭窄患者40例, 根据CTA测量狭窄程度分为中度狭窄(50%-69%)组14例和重度狭窄(70%-99%)组26例, 另根据药物疗效将重度狭窄组分为有效亚组16例和无效亚组10例。利用CTP评估狭窄侧与对侧的绝对灌注值, 包括脑血流量(CBF)、脑血容量(CBV)和达峰时间(TTP), 及相对灌注值(rCBF、rCBV、rTTP), 评价支架治疗术前及术后脑血流动力学情况。结果 中度狭窄组狭窄侧与对侧比较, 仅TTP差异有统计学意义(t=20.55, P <0.01), 重度狭窄组CBV和TTP的差异均有统计学意义(CBV:t=3.83, P <0.001;TTP:t=8.89, P <0.001)。治疗无效亚组rTTP较有效亚组显著延长(t=-2.18, P=0.04)。无效亚组接受PTAS后, rTTP较术前明显缩短(t=5.94, P <0.001)。结论 CTP能有效评估MCA狭窄患者脑血流动力学的变化, 筛选介入治疗患者, TTP能敏感反映术后血流动力学改变。     

128排CT灌注成像诊断脑血管疾病

目的 探讨128排CT全脑灌注成像在缺血性脑血管疾病中的临床应用价值。 方法 对40例拟诊为缺血性脑血管病的患者,均在发病24 h内行头颅CT平扫、头颅CT灌注(CTP)检查,在发病24~72 h内复查MR DWI。分别将CT检出的病灶和MRI检出的病灶与CTP结果相比较。 结果 40例患者中,常规CT平扫于17例患者中共发现20个病灶,CTP检出42个病灶。CTP较常规CT平扫多检出的22个病灶中,15个病灶表现为脑血流量(CBF)与脑血容量(CBV)均较健侧下降,对比剂平均通过时间(MTT)及达峰时间(TTP)均较健侧明显延长或不可测量;4个病灶CBF较健侧降低,CBV较健侧稍增加或维持正常;3个病灶表现为整个大脑半球MTT及TTP较健侧明显延长,CBF与CBV较健侧未见明显减低;复查MR DWI证实其中35个病灶CBF与CBV均下降的病灶发展为梗死灶。 结论 在缺血性脑血管病发病24 h时间窗内,与常规CT平扫相比,128排CT全脑灌注能明显提高脑缺血灶的检出率,对早期发现脑缺血灶和避免病灶漏诊具有重要价值。     

头颈部CTA联合全脑CT灌注一站式扫描中时间间隔对灌注参数的影响

目的 探讨头颈部CTA联合全脑CT灌注（CTP）一站式扫描中,时间间隔对灌注参数的影响。方法 回顾性分析60例急性脑缺血症状患者的标准脑CTP图像（标准组）,于颅脑CTP图像中将动脉峰值期前后各1组扫描数据剔除,使得其前后间隔时间增加至4.5 s,模拟头颈部CTA联合全脑CTP一站式扫描（模拟组）。计算标准组与模拟组灌注参数[脑血流量（CBF）、脑血容量（CBV）、平均通过时间（MTT）]绝对百分比误差值,并分析脑灰质左侧与右侧、白质左侧与右侧灌注参数比值（rCBF、rCBV、rMTT）的相关性。结果 基底核层面CBF、CBV、MTT的绝对百分比误差值均值均<10%。灰质左侧与右侧rCBF（r=0.988,P<0.001）、rCBV（r=0.963,P<0.001）、rMTT（r=0.983,P<0.001）均呈正相关,白质左侧与右侧rCBF（r=0.980,P<0.001）、rCBV（r=0.957,P<0.001）、rMTT（r=0.986,P<0.001）均呈正相关。结论 头颈部CTA联合全脑CTP一站式扫描中时间间隔对灌注参数的影响较小。     

评估急性脑梗死静脉溶栓治疗后CT灌注变化及疗效

目的 利用CT灌注成像（CTPI）评价重组组织型纤溶酶原激活剂（rt-PA）治疗急性脑梗死疗效。方法 根据CTPI检查存在缺血半暗带与否,将100例发病6 h内急性脑梗死患者分别纳入观察组（n=56）或对照组（n=44）,均给予rt-PA治疗。比较治疗前后CTPI梗死区域脑血容量（CBV）、脑血流量（CBF）和平均通过时间（MTT）;检测血栓相关因子水平,评价神经功能缺损和日常生活能力改善情况。结果 治疗后观察组梗死核心区和缺血半暗带区CBV和CBF较治疗前明显增加,MTT明显降低（P均<0.05）,且观察组CBV和CBF均明显高于对照组（P均<0.05）。治疗后观察组血栓相关因子水平均降低（P<0.05）,NIHSS评分和Barthel指数（BI）明显改善,且改善程度均优于对照组（P<0.05）。结论 CTPI指导rt-PA静脉溶栓治疗能明显改善缺血半暗带脑组织灌注,降低血栓形成风险,减轻神经功能缺损,提高日常生活能力。     

CT灌注成像评价单侧颈动脉闭塞脑血流动力学与侧支代偿方式

目的 探讨CT灌注成像(CTP)联合DSA评估单侧颈动脉闭塞(CAO)患者侧支代偿方式对脑血流动力学状态影响的价值。 方法 根据DSA结果将38例患者按不同侧支代偿方式分为两组:单纯初级侧支代偿组(n=14,Ⅰ组)和次级侧支代偿或初级和次级侧支共同代偿组(n=24,Ⅱ组),分别计算两组患者闭塞侧与对侧CTP参数的均值(CBF、CBV、TTP)和相对比值(rCBF、rCBV、rTTP)。比较两组患者闭塞侧与对侧及组间血流动力学差异。 结果 第Ⅰ组患者闭塞侧与对侧相比仅TTP值延长(t=7.54,P＜0.01);第Ⅱ组患者闭塞侧CBV和TTP值较对侧增大(t=5.49、10.70,P均＜0.01)。两组rCBF差异无统计学意义(Z=0.68,P=0.494),rCBV与rTTP差异均有统计学意义(Z=2.32、4.50,P均<0.05)。 结论 CTP联合DSA可全面评价CAO患者脑血流动力学损伤情况以及不同侧支代偿方式脑血流动力学的差异。     

全脑CTP定量分析颅内动脉粥样硬化性狭窄患者血管表面渗透性

目的 采用计算机断层扫描灌注成像（CTP）观察颅内动脉粥样硬化性狭窄（ICAS）患者脑组织血管表面渗透性（PS）和血流动力学状态及治疗后改变。方法 对59例ICAS患者（ICAS组）及16名志愿者（对照组）行全脑CTP，并对ICAS组17例行责任血管支架植入术。采用定量分析软件测量责任动脉供血区血管PS、血流动力学参数[脑血流量（CBF）、血容量（CBV）及平均通过时间（MTT）]，并获得健侧镜像值，比较2组血管PS及血流动力学参数的差异，对比ICAS组支架植入前后血管PS及血流动力学参数变化，分析血管PS与血流动力学参数的相关性。结果 相比对照组，ICAS组患侧血管PS值增高、CBF减低、MTT延长（t=7.77、-4.84、7.47，P均<0.05）。相比健侧，ICAS组患侧血管PS值增高、CBF减低、CBV增加、MTT延长（t=-4.38、-4.48、4.49、8.35，P均<0.05）；植入支架后患侧血管PS值、CBF、MTT与术前差异均有统计学意义（t=0.95、-4.05、3.50，P均<0.05）。血管PS与MTT、CBV分别呈高度、中度正相关（r=0.86、0.59，P均<0.05），与CBF呈低度负相关（r=-0.31，P<0.05）。结论 血管PS可作为定量评价ICAS治疗效果的影像学标志物。ICAS患者患侧脑组织血管PS明显增加，植入支架后较术前明显降低。PS结合血流动力学参数能更准确地反映脑组织病理生理改变，为个性化治疗ICAS及评估疗效提供参考。     

多层螺旋CT脑灌注成像与血管成像联合评价颈动脉狭窄性短暂性脑缺血发作

目的 探讨多层螺旋CT脑灌注成像(CTP)与CTA联合评价颈动脉狭窄性短暂性脑缺血发作(TIA)的价值。 方法 对26例临床诊断TIA患者行头颅CT平扫、脑CTP和颈动脉CTA。评价脑CTP的达峰时间(TTP)、脑血流量(CBF)、脑血容量(CBV)以及颈动脉的狭窄程度及斑块的性质。选取20名无TIA病史的志愿者作为对照。 结果 26例中,21例头颅CT平扫正常,5例有腔隙性脑梗死。脑CTP检查正常9例,异常17例,患者患侧与对侧的TTP、CBF差异有统计学意义(P<0.01)。CTA显示颈动脉狭窄19例,发现颈动脉斑块44处。随访6个月中3例发生脑梗死。 结论 脑CTP结合CTA对评价TIA具有较高的临床应用价值。     

THBS-1、PPBP联合CTP对缺血性脑卒中的诊断价值分析

目的 探讨血小板反应蛋白1(THBS-1)、前血小板碱性蛋白(PPBP)联合CT灌注成像(CTP)对缺血性脑卒中的诊断价值。方法 将2020年1月至2021年1月该院收治的缺血性脑卒中患者136例纳入研究作为研究组,另选取同期于该院进行体检的健康志愿者100例作为对照组。利用蛋白免疫印迹方法检测THBS-1和PPBP蛋白表达水平。研究组进行CTP检查,通过软件分析获得平均通过时间(MTT)、达峰时间(TTP)、脑血容量(CBV)、脑血流(CBF)数据。利用Pearson进行相关性分析,受试者工作特征曲线分析THBS-1、PPBP和CTP分析数据及对缺血性脑卒中的诊断价值。结果 研究组THBS-1、PPBP、MTT、TTP高于或多于对照组,CBV、CBF少于对照组,差异有统计学意义(P<0.05)。THBS-1、PPBP及MTT、TTP随缺血性脑卒中严重程度增加而升高或增加,差异有统计学意义(P<0.05)。CBV、CBF随缺血性脑卒中严重程度增加而减少,差异有统计学意义(P<0.05)。MTT、TTP与THBS-1、PPB呈正相关,CBV、CBF与CBV、CBF呈负相...     

全脑CT灌注参数快速评价脑梗死核心及缺血半暗带

目的 探讨全脑CT灌注(CTP)参数 快速评价脑梗死核心和缺血半暗带的方法。方法 对31例疑似急性缺血性卒中(AIS)患者行全脑 CTP联合头颈部CTA检查,获得CBF和MTT及头颈部CTA图。CTP检查结束3天内行头颅MR检查。观察梗死核心在CBF及DWI图像的部位、数量、面积;测量梗死核心、缺血半暗带及各自镜像区的CBF和MTT,计算相对CBF(rCBF)、相对MTT(rMTT)。结果 31例疑似脑梗死患者,CBF共检出24例33个梗死灶,10例存在缺血半暗带。MRI共检出26例97个梗死灶。CBF及DWI测量梗死核心区面积相关性良好(r=0.98,P=0.07)。脑缺血半暗带区CBF为(6.79±1.29)ml/(100 g·min),MTT为(17.07±3.13)s,rCBF为0.71±0.09,rMTT为1.53±0.19。结论 选择MTT延长区与CBF明显减低不匹配区可较快速、准确地检出缺血半暗带。诊断患者有无脑梗死时,CBF与DWI具有良好的一致性,但CBF不能取代DWI进行脑梗灶数量的诊断。     

CT灌注参数和围手术期临床资料用于预测成年烟雾病患者接受联合搭桥术后发生脑过度灌注综合征

目的 观察术前CT灌注(CTP)参数及围手术期临床资料用于预测联合搭桥术治疗成年人烟雾病(MMD)后过度灌注综合征(CHS)的价值。方法 回顾性收集60例接受联合搭桥术的成年MMD患者,根据术后是否发生CHS分为CHS组(n=18)和非CHS组(n=42);比较组间术前1周内头颅CTP参数和围手术期临床资料差异,采用logistic回归分析评估术后CHS的危险因素,并以受试者工作特征曲线评估各参数预测CHS的效能。结果 组间术前脑血容量(CBV)、流量提取乘积(FEP)及术后当日平均动脉压(MAP)差异均有统计学意义(P均＜0.05)。术前FEP及术后当日MAP较高是联合搭桥术治疗成年MMD后发生CHS的危险因素。以术前CBV、FEP及术后当日MAP预测联合搭桥术治疗成年MMD后发生CHS的曲线下面积(AUC)分别为0.712、0.771及0.665,三者联合AUC为0.872,高于各单一因素(Z=2.17、2.77、3.13,P均＜0.05)。结论 术前CBV、FEP及术后当日MAP有助于预测成年MMD患者接受联合搭桥术后发生CHS;联合应用三者可提高预测效能。     

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.