儿童畸胎瘤样肾母细胞瘤的CT诊断与分型

目的：探讨畸胎瘤样肾母细胞瘤(TWT)的CT表现、分型及临床价值。材料与方法：收集至少CT资料完整的我院病理证实和PubMed搜索“teratoid Wilms tumor”及“teratoid nephroblastoma”主题词相关文献的儿童TWT病例,回顾性分析其CT表现并作CT分型。结果：TWT本院7例(单发)、文献22例(单发19例、双肾病变3例)共32个病灶,其中肾内27个、肾外5个(腹膜后间隙4个)。CT上均表现为轻度非均质强化的混杂密度肿块,其中Ⅰ型11个(11/32,34.38%),明确显示瘤内脂肪组织及钙化灶Ⅰa型4个(4/32,12.5%)、瘤内未见明确钙化灶Ⅰb型7个(7/32,21.88%)；Ⅱ型21个(21/32,65.63%),瘤内未见明确脂肪组织但可测出负CT值脂肪成分且显示瘤内钙化灶Ⅱa型6个(6/32,18.75%)、瘤内未见钙化灶Ⅱb型15个(15/32,46.88%)。结论：TWT的CT影像颇具特征性,表现为2个类型及4个亚型,对儿童肾内、外TWT术前诊断和鉴别诊断具有重要价值。     

儿童胰腺实性假乳头状瘤CT表现

目的 探讨儿童胰腺实性假乳头状瘤（SPTP）的CT特征。方法 回顾性分析经病理确诊的20例SPTP患儿的CT及手术病理资料。结果 CT显示20例SPTP均为单发,5例（5/20,25.00%）位于胰腺头颈部,15例（15/20,75.00%）位于胰腺体尾部。1例（1/20,5.00%）肿瘤平扫呈均匀稍低密度,增强后无明显强化,病理显示该瘤灶内全部为坏死组织;19例（19/20,95.00%）肿瘤平扫呈不均匀稍低密度,增强后不均匀强化。3例（3/20,15.00%）肿瘤内见结节状或边缘壳样钙化;肿瘤不同程度压迫周围组织,3例（3/20,15.00%）胆总管继发性轻度扩张;均未见局部浸润。术后病理结果显示1例肿瘤为多发,4例肿瘤浸润周围组织器官;肿瘤内部均可见不同程度坏死和出血。结论 SPTP的CT表现具有一定特征性,有助于临床诊断。     

儿童肝包虫病的CT特点

目的 探讨儿童肝包虫病的CT表现。方法 回顾性分析27例经病理和/或血清学证实的肝包虫病患儿的临床和CT资料。结果 27例肝包虫病中,肝囊型包虫病26例,肝泡型包虫病1例;单纯肝包虫病10例,合并其他器官包虫病17例;肝内单发包虫18例,多发包虫9例。共发现囊型病灶47个,其中单囊型囊肿占51.06%（24/47）,内囊塌陷型囊肿占42.55%（20/47）,钙化型囊肿占4.26%（2/47）,多子囊型囊肿占2.13%（1/47）,未见实变型囊肿;泡型病灶1个。74.47%（35/47）的囊肿直径>5 cm。结论 CT可定性诊断儿童肝包虫病,是可靠的检查方法。     

儿童先天性肺气道畸形的CT表现与病理对照分析

目的 探讨儿童先天性肺气道畸形（CPAM）的CT征象及其与病理改变的关系。方法 回顾性分析经手术病理证实的142例CPAM的临床及CT资料，采用Stocker 5型分法对142例CPAM进行病理分型，观察其CT特征，并与病理结果对照。结果 本组142例CPAM患者中，Stocker 1型52例（52/142，36.62%），CT表现为肺内多发大小不等含气囊肿；2型68例（68/142，47.89%），CT表现为肺内多发含气小囊肿；3型1例（1/142，0.70%），CT表现为右肺大片实变，其内见少许充气支气管影及含气小空腔；4型21例（21/142，14.79%），CT表现为肺外周多发分隔的巨大囊腔；未见0型病例。结论 CT可有效提示CPAM的病理类型。     

儿童肾上腺皮质癌临床及影像学表现

目的 观察儿童肾上腺皮质癌（ACC）临床及影像学表现。方法 回顾性分析13例经病理确诊的ACC患儿，其中11例术前接受肾上腺CT检查，4例术前接受肾上腺MRI，观察其临床特点及影像学表现。结果 ACC患儿中女性多见（10/13，76.92%），临床症状包括明显男性化（9/13，69.23%）、库欣综合征（4/13，30.77%）、阴蒂肥大（3/13，23.08%）、阴毛早现（3/13，23.08%）及腹痛腹部包块（2/13，15.38%）等，多伴血清雄激素升高（10/13，76.92%）。CT显示肾上腺区较大肿物，最大径常>6 cm（7/13，53.85%），呈分叶状（8/13，61.54%），5例（5/11，45.45%）平扫密度不均匀，内见钙化灶；增强后均呈不均匀明显强化（11/11，100%），8例（8/11，72.73%）可见"网络状"改变，并可累及周围组织（2/11，18.18%），局部形成肾静脉或下腔静脉癌栓。MR T2WI中，3例病灶呈稍高信号，1例呈等信号；T1WI 3例呈稍低信号，1例呈等信号；增强后4例病灶均不均匀强化。结论 儿童ACC影像学表现具有一定特征性，结合临床有助于诊断。     

18F-FDG PET/CT诊断肾细胞癌

目的 探讨¹⁸F-FDG PET/CT诊断肾细胞癌（RCC）的价值。方法 回顾性分析32例确诊为RCC患者的病理及PET/CT影像资料,比较不同病理类型（透明细胞癌与非透明细胞癌）、Fuhrman分级（高级别与低级别透明细胞癌）和临床分期（有无远处转移）RCC的肿瘤直径和最大标准摄取值（SUV_max）差异。结果 32例患者共33个原发灶,PET/CT检出31个,2个假阴性,检出率为93.94%（31/33）。31个原发灶PET/CT表现为肾实质内混杂密度的软组织团块,其¹⁸F-FDG摄取可接近、高于或低于正常肾实质;2个原发灶PET/CT未见异常表现。8例伴静脉瘤栓,19例伴远处转移,瘤栓及转移灶的FDG摄取均高于受累器官本底。不同病理类型组和不同Fuhrman分级RCC的肿瘤最长径及SUV_max差异无统计学意义;不同临床分期RCC的肿瘤最长径差异无统计学意义,SUV_max差异有统计学意义（t=3.852,P=0.001）。结论 RCC原发灶的PET/CT表现多样,较小的低级别肾透明细胞癌可无明显异常表现而漏诊;¹⁸F-FDG PET/CT在RCC术前分期中具有重要价值。     

儿童肝母细胞瘤CT征象及其与病理的关系

目的 探讨儿童肝母细胞瘤CT征象及其与病理分型间的关系。方法 回顾性分析我院经病理证实的110例儿童肝母细胞瘤患者的CT及病理资料。结果 110例儿童肝母细胞瘤患儿,肿瘤位于右叶67例（67/110,60.90%）、左右叶25例（25/110,22.72%）、左叶15例（15/110,13.63%）、尾叶3例（3/110,2.72%）;瘤体平均大小为（287.14±272.36）cm³;多数病灶为单发（94/110,85.45%）、类圆形（96/110,87.27%）;病变多分界清晰（86/110,78.18%）;瘤内坏死囊变不规则102例、钙化60例;肺转移较常见（23/110,20.90%）;约50.90%血管受累（56/110）,5例出现淋巴结转移。不同病理分型儿童肝母细胞瘤患儿的肿瘤钙化、肿瘤均匀强化程度差异存在统计学意义（P均<0.001）。结论 CT检查可对肝母细胞瘤术前诊断及鉴别诊断提供帮助。     

胞内分枝杆菌肺病CT特征:与堪萨斯、脓肿/龟分枝杆菌肺病比较

目的 探讨胞内分枝杆菌肺病的CT特征,并与堪萨斯分枝杆菌、脓肿/龟分枝杆菌肺病比较。方法 回顾性分析经临床及实验室检查证实的35例胞内分枝杆菌肺病、18例堪萨斯分枝杆菌肺病和22例脓肿/龟分枝杆菌肺病的胸部CT表现,比较其CT特征。结果 胞内分枝杆菌肺病病灶多分布于双肺（33/35,94.29%）、累及多个肺叶（18/35,51.43%）或全部肺叶（16/35,45.71%）,主要表现为索条影（34/35,97.14%）、实变（33/35,94.29%）、小叶中心结节和树芽征（32/35,91.43%）、胸膜增厚（32/35,91.43%）、磨玻璃密度影（31/35,88.57%）、牵拉性支气管扩张（30/35,85.71%）、非牵拉性支气管扩张（25/35,71.43%）、结节（24/35,68.57%）、肺内钙化（24/35,68.57%）和空洞（23/35,65.71%）。胞内分枝杆菌肺病磨玻璃密度影多于堪萨斯分枝杆菌（P=0.001）、脓肿/龟分枝杆菌肺病（P<0.001）。胞内分枝杆菌肺病空洞壁厚于堪萨斯分枝杆菌（P=0.019）、脓肿/龟分枝杆菌肺病（P=0.024）。胞内分枝杆菌肺病肺内钙化多于堪萨斯分枝杆菌（P=0.014）、脓肿/龟分枝杆菌肺病（P=0.007）。结论 相比堪萨斯、脓肿/龟分枝杆菌肺病,胞内分枝杆菌肺病CT表现具有一定特征性,有助于鉴别诊断。     

第三代双源CT早期鉴别诊断急性缺血性脑卒中患者血管内治疗后颅内出血灶与碘对比剂

目的 探讨第三代双源CT早期鉴别诊断急性缺血性脑卒中（AIS）血管内治疗后颅内出血灶与碘对比剂的价值。方法 纳入78例接受血管内治疗的AIS患者,治疗后采用第三代双源CT行脑部CT双能量（80 kV/Sn150 kV）扫描,经后处理得到碘分布图和虚拟平扫图像。以发病24~48 h后常规脑部CT图像为参考,计算双能量CT（DECT）诊断颅内出血的准确率、敏感度、特异度、阳性预测值（PPV）和阴性预测值（NPV）。结果 共31例患者（53个颅内高密度灶）纳入分析,其中DECT正确诊断26个高密度灶为存在出血,23个高密度灶为碘对比剂;1个钙化灶误诊为出血合并对比剂,3个DECT诊断为对比剂的病灶出现延迟性出血转化。DECT鉴别诊断颅内出血灶与碘对比的敏感度、特异度和准确率分别为89.66%（26/29）、95.83%（23/24）和92.45%（49/53）,PPV为96.30%（26/27）,NPV为88.46%（23/26）。结论 第三代双源CT能早期准确诊断AIS血管内治疗后的出血转化,有助于临床及时调整治疗方案。     

多层菊形样胚胎性肿瘤影像学表现

目的 观察多层菊形样胚胎性肿瘤（ETMR）影像学表现。方法 回顾性分析8例经病理证实ETMR患儿的MRI（n=8）和CT（n=6）资料,观察其影像学表现。结果 MRI中,8例ETMR最大径32~96 mm,边缘清晰,5例位于幕上、3例位于幕下;幕上ETMR均为巨大囊实性肿块,幕下ETMR体积较小,均未见瘤周水肿。6例ETMR为囊实性,囊性部分呈低T1WI、高T2WI信号且均位于肿瘤边缘,增强后5例实性部分轻度局灶性不均匀强化、1例未见明显强化;其中5例见瘤内出血,5例瘤内见流空血管影,3例侵犯邻近硬脑膜。2例ETMR为实性,增强扫描可见局灶性结节状不均匀强化,且强化部分与表观弥散系数（ADC）图上的低信号区对应;其中1例胆碱（Cho）/肌酸（Cr）升高,N-乙酰天冬氨酸（NAA）降低。弥散加权成像（DWI）中,8例ETMR均显示弥散受限。6例接受CT扫描的患儿中,4例见条片状或点状钙化,与MRI低信号区对应。结论 ETMR多为幕上较大囊实性肿块,边缘清楚,囊变常位于肿瘤边缘,可见特征性血管流空影,常伴瘤内出血,可见钙化,无瘤周水肿,DWI明显弥散受限;增强后实性部分轻度不均匀强化。     

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.