胃肠道间质瘤的CT征像分析

目的:探讨胃肠道间质瘤的CT表现特征。方法:回顾性分析经手术及病理证实的11例胃肠道间质瘤患者的CT影像资料,并将大体病理所见与CT表现相对照。结果:肿瘤位于胃部2例,十二指肠2例,空肠3例,回肠2例,直肠1例,肠系膜内1例。发生于小肠的7例中4例有便血史或便潜血阳性。11例中恶性肿瘤8例,交界性2例,良性1例。11例中10例肿块CT表现为外生性肿块,多较大,其中恶性肿块直径4～16cm,直径<5cm者1例,≥5cm者7例。肿物密度不均匀,呈囊实性,实性部分中度至明显强化,肿块内伴有溃疡形成1例。结论:胃肠道间质瘤的CT表现具有一定特点,CT检查有助于胃肠道间质瘤的定位,以及观察肿瘤与周围组织结构关系情况。     

小肠间质瘤的CT诊断

目的:探讨和分析小肠间质瘤(GIST)的CT检查方法和表现特点。方法:回顾分析我院2001年9月~2005年2月间经手术、病理、免疫组化确诊的小肠间质瘤病例20例,所有病例均作了CT增强检查和多平面重建观察,结果:病灶发生于十二指肠6例,回肠10例,空肠4例。其中10例为良性间质瘤,10例为恶性间质瘤,平扫时病灶密度通常较均匀,但也可不均匀,增强后肿瘤均明显强化,良性肿瘤直径平均为2.4cm,恶性肿瘤直径平均为7.6cm,以4cm直径为界判定其良、恶性,则符合率可达90%。结论:多层螺旋CT(MSCT)是小肠间质瘤主要的影像学诊断方法,以饮水法充盈肠腔并作增强后双期扫描有利于提高诊断质量,根据肿块大小可有助于良、恶性肿瘤的鉴别。     

小肠间质瘤的CT影像诊断

目的:探讨小肠间质瘤的CT影像学特点.方法:选择经手术并病理证实的小肠间质瘤12例行CT平扫,后均作双期增强检查.结果:病灶位于十二指肠2例,回肠6例,空肠4例.肿瘤呈圆形或类圆形5例,肿瘤形态不规则,呈分叶状7例;肿瘤最大直径7～10 cm,平均4.5 cm;平扫时肿瘤呈软组织密度,有6例肿块内见低密度坏死囊变区;7例肿瘤边缘实质部分明显强化,5例肿瘤轻～ 中等强化;静脉期肿瘤均持续增高强化,6例肿块内低密度坏死囊变区增强后无强化;7例肿瘤突破浆膜向肠腔外生长.结论:小肠间质瘤CT平扫呈软组织密度,双期增强后呈持续明显增高强化,对术前诊断有较大价值.     

小肠间质瘤的CT表现及其与病理的对照研究

目的分析小肠间质瘤的影像学特点,探讨CT对该肿瘤的诊断价值。方法回顾性分析经手术病理证实的21例小肠间质瘤CT的特点。并与临床病理学的表现进行对照。结果21例患者共检出病灶25个,18例为单发,3例多发。以空肠较常见（11/25）。4例良性肿瘤直径1.5～3.5 cm,均为单发病灶。良性肿瘤CT平扫表现为类圆形的均匀软组织密度影,直径均小于4.0 cm,增强后均匀轻度强化。17例恶性肿瘤共21个病灶,每例均有1个病灶直径均大于4.0 cm,多为腔外生长,呈分叶状或不规则形,肿瘤常出现囊变坏死,瘤内可见气体或有口服对比剂,以及形成气液平,增强扫描呈环形或不规则强化,囊变坏死区不强化。肿瘤可转移至肝脏。以肿瘤直径是否大于4.0 cm评价肿瘤的良恶性,本组准确率可达100%。结论小肠间质瘤在CT上有一定特征性,多表现为腔外或混合性生长的肿块,瘤内可见气体密度或对比剂影。CT可作为诊断小肠间质瘤的重要检查方法。     

十二指肠恶性间质瘤的CT诊断

目的：探讨CT对十二指肠恶性间质瘤的诊断价值。方法：对1996—2007年发现的12例经病理证实的十二指肠恶性间质瘤的CT表现进行回顾性分析。结果：其主要CT表现为：①右上腹部巨大肿块,且与十二指肠关系密切;②肿块多数向十二指肠腔外生长,呈分叶状改变;③部分肿块中心液化、坏死,如与肠腔沟通,则肿块内可见气体与造影剂形成的液平影;④大多数病灶增强后明显不均匀性强化。结论：CT对十二指肠恶性间质瘤的诊断有重要价值。     

高危险程度胃肠道间质瘤的CT表现

目的探讨高危险程度胃肠道间质瘤（HRGIST）的CT表现特征。方法回顾性分析2009年8月-2014年3月24例经手术病理证实的HRGIST的CT表现,并讨论其CT特征。结果肿瘤位于胃部12例,小肠11例（十二指肠/空肠/回肠=5/4/2）,直肠1例;肿块最大径2.5~15.0 cm,最大径〉5 cm者22例,〈5 cm者2例;24例中20例肿块形态不规则,21例周围脂肪间隙模糊;24例肿块均可见不同程度坏死囊变,15例溃疡形成,2例瘤体破溃穿孔,伴腹腔积液、积气,3例可见钙化。增强扫描大部分呈中度至明显不均匀强化,其中小肠HRGIST较胃HRGIST强化更明显,并可见丰富的血管供应;3例伴发肝脏多发转移。结论 HRGIST的CT表现有一定特征性,熟悉其影像学表现有助于对该病的诊断。     

多层螺旋CT双期动态增强扫描对小肠原发性肿瘤的诊断价值

目的 评价多层螺旋CT(multi-slice CT,MSCT)双期动态增强扫描小肠原发性肿瘤的诊断价值及其临床意义.方法 回顾性分析21例经手术病理和免疫组织化学证实的小肠原发性肿瘤(十二指肠和壶腹周围肿瘤除外)的临床及CT资料.结果 1)腺癌10例,其中空肠近端7例、回肠远端3例.平扫表现:肠壁不规则、局限性增厚,形成突入肠腔肿块,伴肠腔狭窄,4例合并小肠梗阻.增强扫描:病灶中等不均匀强化,局部肠系膜和腹膜后淋巴结肿大3例.2)间质瘤6例:空肠间质瘤4例、回肠间质瘤2例.平扫表现:肠襻向腔外生长呈类圆形或分叶状肿块.4例较大肿瘤中间区域有出血坏死;2例边界不清,与周围肠管粘连.增强扫描:肿瘤实质期明显强化,且延迟强化.3)淋巴瘤4例:回肠近端1例、回盲部2例、空肠1例.平扫表现:肠壁呈环形增厚.肠壁不对称性增厚2例,在肠系膜形成分叶样肿块、多节段受累2例,肠系膜及腹膜后淋巴结多发性肿大3例.增强扫描:动脉期和门脉期强化不均匀,肠系膜血管被肿瘤包绕2例,无受压移位.4)脂肪瘤1例,位于空肠近端,表现为空肠内类圆形低密度肿块,无强化.结论 MSCT双期动态增强扫描能准确显示所有肿块的部位、大小,并能根据肿瘤强化程度、形态判断肿瘤的性质.     

胃神经鞘瘤CT检查误诊原因分析

目的探讨胃神经鞘瘤CT影像特征并分析误诊原因。方法回顾性分析5例经手术病理检查证实但CT检查误诊的胃神经鞘瘤临床资料。结果5例均以上腹部不适、匕腹部肿块、黑便等就诊,均行七腹部CT扫描。CT影像表现为边界锐利的类网形均质肿块．与肌肉组织比较呈低密度,向腔内或腔外生长,病灶长径平均（6．2±2．3）cm,其中4例病变长径〉5．0cm。5例CT检查误诊为恶性胃间质瘤2例,胃平滑肌瘤、胃外肿瘤及偏良性胃间质瘤各1例,均经手术病理及免疫组织化学染色榆奄确诊胃神经鞘瘤。结论对CT表现为胃肠道壁内均质性、边界清晰的肿块,且无出血、坏死和囊变时,应警惕胃神经鞘瘤。     

小肠肿瘤及肿瘤样病变的CT表现

目的 分析小肠肿瘤及肿瘤样病变的病理特征及其CT表现。方法 收集2009年12月—2010年7月经手术及病理证实的小肠肿瘤及肿瘤样病变患者72例,分析其病理特征及CT 表现。结果 ①上皮性肿瘤:3例腺瘤,其中2例位于十二指肠,1例位于空肠近段;CT表现为肠腔内的圆形软组织密度肿块,有蒂或无蒂,表面光滑,较大者可表现为无蒂菜花状肿块,可出现肠梗阻或肠套叠,其中1例肿块直径4cm,伴发肠套叠。28例腺癌,其中17例位于十二指肠,10例位于回盲部,1例位于回肠中段;CT表现为肠腔内的肿块伴有局部肠壁的不规则增厚、肠腔狭窄,增强后肿块及增厚肠壁多不均匀强化,表面不光整。小肠腺癌有早期发生局部淋巴结转移的倾向,常出现在肠系膜根部,增大的淋巴结易于侵犯肠系膜血管。本组发生于回盲部的腺癌伴发回-结肠套叠。4例类癌中3例位于十二指肠,1例位于回盲部。文献显示类癌好发于远端回肠,其次为空肠,而靠近十二指肠的类癌较少分泌激素,主要表现为肠梗阻和局部感染。CT均表现为肠腔内的类圆形软组织结节,明显强化。类癌可发生淋巴结转移、肝脏转移,本组1例发生淋巴结转移。其中1例为位于回肠远段的原发性神经外胚层肿瘤(PNET),是一种较为罕见的高度恶性的神经系统肿瘤,为神经嵴衍生的较原始的肿瘤,主要由原始神经上皮产生,具有多向分化的潜能,预后极差,大部分仍需通过病理诊断才能确诊。1例回盲部炎性肌纤维母细胞瘤,表现为回盲部较大肿块,较光滑,中度均匀强化,同时伴小肠梗阻。②非上皮性间叶组织肿瘤:15例间质瘤,其中位于十二指肠2例,空肠3例,回肠10例;胃肠道间质瘤(GISTs)指原发于胃肠道、大网膜和肠系膜的c-KIT(CD117,干细胞因子受体)染色阳性的梭形细胞或上皮样细胞的一组间叶源性肿瘤。组织病理学分型包括:平滑肌分化型、神经分化型、混合分化型和未分化型。免疫组化CD117阳性是间质瘤特征性标志,CD34是辅助指标。间质瘤最常发生于胃,发病率约为60%~70%,小肠发病率占20%。小肠间质瘤发生于回肠多见,十二指肠少见。小肠间质瘤好发于肠壁肌层的两端,多沿肠壁的垂直方向生长,具有瘤体大但较局限的生长特点,多呈向腔内、腔外、腔内外同时生长的圆形或类圆形软组织肿块,表面可伴有溃疡形成。肿瘤血供丰富,渐进性强化(均匀或不均匀)是小肠间质瘤的主要强化方式。低度恶性间质瘤一般直径多小于5cm,形态较规则,密度均匀,偶见点状钙化,与周围器官或组织分界较清,或轻度占位效应,极少侵犯邻近器官或组织。恶性间质瘤直径多大于5cm,向腔内(外)生长,形态欠规则,肿块密度多不均匀,常伴有出血、坏死、囊变,与周围器官或组织分界欠清晰。分隔状强化的胃间质瘤多为恶性且预后较差,多发性胃间质瘤预后较差。GISTs以血行转移为主,很少发生淋巴结转移,并有一定的种植转移几率。消化道肿瘤常见于食管,小肠罕见。CT表现为局限性肿块,位于腔内或同时向腔外生长,密度均匀,表面光滑,邻近肠壁正常。本组1例为回肠远段恶性平滑肌瘤。3例脂肪瘤,其中1例位于十二指肠,2例位于回肠远段及回盲部,脂肪瘤多起源于肠壁黏膜下层脂肪组织,CT均表现为与肠管关系密切的脂肪密度肿块,CT值为-80~-120HU,密度均匀,相邻肠壁不增厚,具有很大的特征性。③淋巴瘤:12例淋巴瘤,最易累及的部位是远段小肠,本组十二指肠1例,小肠远段或回盲部11例。CT表现如下:A.肠壁的多发结节状肿块,边界清楚,本组6例。B.肠壁出现不均匀性增厚(非对称性增厚),受累的肠段较长,本组2例。C.肠管的“动脉瘤样”扩张,本组1例。D.肠系膜和后腹膜的淋巴结可见显著增大,增大的淋巴结包绕肠系膜血管及其周围脂肪,形成所谓的“三明治”征,本组3例。E.其他:淋巴瘤的并发症如穿孔、瘘道形成,肝脾大等。④其他:十二指肠胆结石1例,小肠远段粪石1例同时伴先天性肠旋转不良(右位空肠)、小肠梗阻。胆结石表现为肠腔内环状高密度结节,粪石表现为类圆形团块内为脂性混杂密度,动态观察可发生移动。胰腺异位1例,表现为近段空肠内明显强化的结节,边缘光整,邻近肠壁无增厚,误诊为神经内分泌肿瘤。血管瘤2例,其中小肠血管瘤伴全身多发血管瘤1例,比较罕见,表现为全部小肠腔内多发类圆形低密度结节伴钙化点,增强后无明显强化,同时合并颌面部皮下、胸壁皮下、肝、腹盆腔多发类似结节或肿块,大小不等,体表可见色素沉着影。结论 CT对小肠肿瘤及肿瘤样病变具有较高的诊断价值。     

胃肠道间质瘤5例分析

现将我院自 1998年以来收治的 5例胃肠道间质瘤(GISTs)诊治体会报告如下。1　临床资料本组男 3例 ,女 2例。年龄 49～ 76岁 ,平均 5 8岁。 5例均可触及腹部肿块 ,4例有腹痛 ,1例有肠道出血 ,1例表现为不全肠梗阻 ,1例表现为肠穿孔 ,2例伴低热。 5例均经病理确诊。本组 5例手术探察见胃肿物 1例 ,小肠肿物 4例 ;肿物大小约 9cm× 7cm× 6 cm～ 30 cm× 2 0 cm× 10 cm,血运丰富 ,红色 ,形状不规则 ,均与附近脏器紧密粘连。病理示肿瘤出血、坏死、囊性变 ,其中 2例小肠间质瘤继发肠腔窦道形成 ;均未见淋巴结转移。免疫组化 :3例 SMA( ) ,2…     

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.