不同密度口服阳性对比剂对PET/CT图像质量及标准摄取值的影响

目的探讨不同密度口服阳性对比剂对PET/CT图像质量和标准摄取值(SUV)的影响。方法60例PET/CT显像患者,显像前常规口服浓度为2%的泛影葡胺1000ml,其中14例患者肠道内发现多处高密度残留钡剂。所有患者均同时采用CT及137Cs两种衰减校正方法,分别重建CT衰减校正(CTAC)、137Cs衰减校正(CsAC)图像。选择所有患者胃肠道内泛影葡胺充盈区、无对比剂充盈区、臀部软组织区以及14例患者高密度钡剂充盈区勾划感兴趣区(ROI)。比较各感兴趣区CTAC和CsAC的平均SUV差异,以及CTAC、CsAC的图像差异。结果在所有正常软组织区、无对比剂充盈区以及泛影葡胺充盈区,CTAC和CsAC的平均SUV无显著性差异。在高密度残留钡剂充盈区,CTAC的平均SUV明显高于CsAC(t=3.451,P=0.018),其差异与CT值成正相关(r=0.445,P=0.021)。比较所有图像,正常软组织、无对比剂充盈区、泛影葡胺充盈区CTAC和CsAC图像质量无明显差异。在高密度残留钡剂充盈区,CTAC图像上可见FDG高摄取伪影,而CsAC图像为正常摄取。结论低密度口服泛影葡胺对PET/CT显像图像质量和标准摄取值无明显影响,高密度钡剂可使PET/CT的SUV明显高估,且可出现不同程度的FDG高摄取伪影。     

18F-FDG标准化摄取值在不同衰减校正方式中的比较研究

目的比较应用X线CT和Cs透射数据对PET发射数据进行衰减校正时,标准化摄取值(SUV)的差异。方法以Philips圆柱体空心SUV校正模型和20例患者为研究对象,在PET/CT全身三维显像模式中,分别用X线CT和137Cs透射数据做PET发射数据的衰减校正(CTAC和CsAC)。分别在CTAC及CsAC均匀水模的中心15层横断面图像的相同位置,以及所有患者相同部位的肌肉、脂肪、肠道、肝脏、肺、心肌、脑、骨等不同密度的正常组织中,划取相同大小的感兴趣区(ROI),通过计算机自动测量各ROI的平均SUV,并在CT横断面图像的相应位置测量人体组织的平均CT值。然后将所有被测人体组织分为软组织和骨组织两组,分别比较分析各组中CTAC和CsAC平均SUV的差异,及这种差异与CT值的相关性。全部采用临床全身显像的三维重建算法来重建图像。结果模型研究结果:在不同活性时,CsAC方式均能得到稳定可靠的SUV。而CTAC方式得到的SUV随着放射性活性水平降低,有逐渐升高的趋势。在单位活度6.253MBq/kg至4.292MBq/kg之间,即制造商推荐的标准给药活性(5.18MBq/kg体重)附近,CTAC和CsAC方式测得的SUV相同;患者研究结果:除脑组织以外的所有软组织中,CTAC的平均SUV较CsAC者低17%(t=-5.328,P=0.000),相应部位所测得的CT值为-850～68Hu[平均(-87±295)Hu],平均SUV的差异与相应的CT值呈负相关(r=-0.237,P=0.000);在骨组织中,CTAC的平均SUV较CsAC者高16%(t=7.960,P=0.000),相应部位所测得的CT值为105～550Hu[平均(334±151)Hu],平均SUV的差异与相应的CT值呈正相关(r=0.539,P=0.000)。结论①不同活性水平时,CsAC方式的SUV稳定、可靠,而CTAC方式的SUV稳定性和可靠性差;②模型模拟标准临床显像程序来测试PET/CT定量指标的稳定性具有明确的实用价值;③呼吸运动和组织衰减系数由低能向高能转换过程所带来的误差等,也是影响CTAC方式SUV稳定性的主要因素。     

PET/CT检查过程中口服增强造影剂泛影葡胺对体内FDG代谢的影响

目的:研究口服增强造影剂对体内FDG代谢的影响。方法:63例行PET／CT检查且显像图像未见异常FDG摄取的病人随机分为3组。对照组20例,显像前未口服任何造影剂;增强组26例,显像前40 min服1％的泛影葡胺溶液1 000ml;饮水组(阴性对照组)17例,显像前40 min服清水1 000 ml。静脉注射18F-FDG 0．15 mCi／Kg后45 min进行全身PET／CT显像。在PET横断面图像的左侧小脑皮质、主动脉弓、右肺、肝右叶、第5腰椎椎体和臀部肌肉位置勾画圆形感兴趣区(ROI),计算ROI内的标准摄取值 SUV,并将3组病人各部位SUV的数值进行比较。结果:增强组病人肺、主动脉弓、肝脏及肌肉的FDG摄取均显著低于对照组和阴性对照组(饮水组)(P<0．05);而对照组和饮水组间各部位FDG摄取无显著差异(P>0．05)。结论:PET／CT检查时口服造影剂泛影葡胺有可能影响体内FDG的代谢水平,从而可能影响肿瘤组织对FDG的摄取,在进行诊断和对SUV值分析时应加注意。     

饮水充盈胃CT扫描275例效果分析

目的 探讨饮水充盈胃CT扫描在胃病变诊断中的应用价值.方法 回顾性分析比较275例饮水充盈胃与420例口服泛影葡胺稀释液充盈胃的CT扫描资料.结果 饮水充盈胃CT扫描对胃壁厚度、黏膜侧及胃部病变的显示率高于口服泛影葡胺稀释液(P<0.01);两种方法 对腹腔淋巴结转移显示率均低,差异无显著性意义(P>0.05).结论 饮水充盈胃加静脉推注泛影葡胺(过敏者禁用),对胃的显示具有明显优势,并且可提高胃部病变特别是小病变的显示率.     

口服并灌肠泛影葡胺用于全腹CT扫描的护理体会

目的探讨口服并灌肠泛影葡胺用于全腹CT扫描检查的护理效果。方法将93例全腹CT扫描检查患者随机分为对照组46例和观察组47例。观察组采用检查前1h口服1%-1.5%泛影葡胺1000-1200ml,CT扫描检查时再行1%-1.5%泛影葡胺400-500ml保留灌肠,即行扫描检查。对照组采用于检查前3h口服1%~1.5%泛影葡胺2000ml充盈肠道等待检查。结果观察组肠道造影剂充盈时间比对照组提前1.8-2.04h,两组比较有显著性差异（P〈0.05）。结论口服并灌肠泛影葡胺用于全腹CT扫描检查,减轻了患者的痛苦,提高了影像检查质量和正确诊断率。     

胃肠道肿瘤患者行 PET-CT 检查过程中口服造影剂的护理

目的：探讨如何做好 PET-CT 检查过程中给予口服造影剂的护理配合。方法对200例胃肠道肿瘤患者行静脉注射18F-FDG 后,分次给予1％泛影葡胺溶液口服。结果197例患者口服泛影葡胺溶液后胃肠道充盈较好,图像清晰,无伪影,符合诊断要求。结论胃肠道肿瘤患者行 PET-CT 检查程中口服泛影葡胺时,给予积极有效的护理指导是患者口服对比剂取得满意效果的重要保证。     

衰减校正和散射校正对单光子发射计算机断层成像图像质量的影响

目的 探讨CT衰减校正（CTAC）和双能窗散射校正（SC）对SPECT图像质量的影响。方法 分别对Jaszczak模型、IEC体模及16例患者进行SPECT断层显像,并分别进行以下4种校正状态下的图像重建：无衰减校正（NOAC）无散射校正（NOSC）、SC NOAC、CTAC SC、CTAC NOSC。比较不同校正状态下Jaszczak模型冷区和本底区放射性计数、冷区对比度及均匀区积分均匀性百分比、IEC体模各热区及患者病灶靶/本底比值,并进行统计学分析。结果 与Jaszczak模型的NOAC NOSC图像比较：①CTAC NOSC图像可显著提高冷区和本底区的放射性计数（P<0.05）;降低均匀区的积分均匀性百分比（P<0.05）;冷区对比度的差异无统计学意义（P>0.05）。②SC NOAC显著降低了冷区和本底区的放射性计数（P均<0.05）;提高了均匀区的积分均匀性百分比（P<0.05）;显著提高了冷区对比度（P均<0.05）。③CTAC SC提高了冷区和本底区的放射性计数及冷区对比度（P均<0.05）;降低了均匀区的积分均匀性百分比（P<0.05）。与IEC体模及患者的NOAC NOSC图像比较,CTAC NOSC图像各热区及病灶的靶/本底比值差异均无统计学意义（P均>0.05）,SC NOAC图像各热区（除直径10 mm）及病灶的靶/本底比值均较大（P均<0.05）,CTAC SC图像各热区及病灶的靶/本底比值均较大（P均<0.05）。结论 CTAC可提高图像放射性计数及均匀性,SC可提高图像对比度,将两者结合可获得较高的图像质量。     

食管癌术后吻合口瘘的影像学诊断

目的分析食管癌术后吻合口瘘的影像学特点,提高早期诊断方法。方法对56例临床高度怀疑食管癌术后吻合口瘘的患者,口服泛影葡胺(60%)或者稀硫酸钡(100%W/V),在X线胃肠机上多体位透视并适时点片。对用上述方法未发现吻合口瘘的病例,再口服泛影葡胺40～60 ml后,行CT吻合口层面动态扫描。结果 56例口服泛影葡胺造影检查,发现吻合口瘘14例;42例口服稀硫酸钡造影检查,发现均首先吻合口瘘3例;39例口服泛影葡胺后CT动态扫描,发现食管吻合口瘘4例。结论食管癌术后口服泛影葡胺(60%)造影检查,多数能够发现瘘口,口服稀硫酸钡(100%W/V)检查和吻合口层面CT动态扫描能够进一步发现吻合口瘘。     

18F-FDGPET/CT显像锁骨上区脂肪摄取2例

例1,女,22岁,发现左颈部肿物1个月,为明确病变性质而行全身18F-FDG PET/CT检查.PET/CT图像显示,左颈部可见一增大淋巴结,FDG摄取明显增高,SUV(标准摄取值)7.1.此外,PET图像上于双侧锁骨上区、胸背部、上纵隔、胸椎旁可见多发大小不等团块状、结节状FDG浓集影,双侧基本对称,边界不清(图1A),浓集程度不一,SUV 3.2～6.7,与CT图像融合后显示浓集影位于肌间隙脂肪组织内(图1B).     

两种肠道准备方法在盆腔CT检查中的应用及效果比较

将120例接受盆腔CT检查的患者随机分为观察组与对照组,观察组60例采用3%甘露醇和1%泛影葡胺同时、分次口服的肠道准备方法,对照组60例采用1%肥皂水清洁灌肠后分次服用1%泛影葡胺的肠道准备方法,比较两组患者肠道充盈效果、不良反应、肠道准备所需时间.结果观察组与对照组比较,其全肠道充盈效果好、不良反应少、肠道准备所需时间短(P＜0.01).认为服用甘露醇和泛影葡胺做肠道准备具有肠道充盈效果好,不良反应少,肠道准备所需时间短等优点.     

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.     

手转胎头术失败的原因与分娩结局临床分析

目的 探讨手转胎头术失败的原因与分娩结局.方法 选择2008年1月至2010年12月于我院住院分娩的持续性枕横位、枕后位产妇198例,根据行手转胎头术后结果分为成功组126例、失败组72例.比较两组分娩结局,对比分析失败原因.结果 失败组胎儿体质量≥3500 g的发生率[76.4％(55/72)]明显高于成功组[31.7％(40/126)],差异有统计学意义(x2=30.177,P=0.001)、失败组宫缩乏力发生率[58.3％(42/72)]高于成功组[38.1％ (48/126)],差异有统计学意义(x2=7.569,P=0.006)、失败组骨盆临界或轻度狭窄发生率[38.9％ (28/72)]高于成功组[23.8％(30/126)],差异有统计学意义(x2 =5.030,P=0.002)、失败组手转胎头时机不当(宫口开大＜6 cm、胎头位于坐骨棘上及宫口开大8～10 cm、胎头位于坐骨棘下≥2 cm)发生率[61.1％(44/72)]高于成功组[38.9％(49/126)],差异有统计学意义(x2=9.084,P=0.003).失败组母儿并发症(产后出血、产褥病率、胎儿窘迫、新生儿窒息)发生率高于成功组(x2 =9.586,P=0.002、x2=9.334,P=0.002、x2=5.910,P=0.015、x2=5.240,P=0.022)、失败组剖宫产发生率[72.2％(52/72)]明显高于成功组[34.1 ％(43/126),x2=26.641,P=0.001)].结论 手转胎头术能使难产变顺产,降低剖宫产率,减少母儿并发症,但须积极预防、处理导致手转胎头术失败的原因,对矫正失败后继续矫正及试产应慎重.