多b值DWI鉴别诊断交界性与恶性上皮性卵巢肿瘤

目的 观察多b值DWI鉴别诊断交界性上皮性卵巢肿瘤（BEOT）与恶性上皮性卵巢肿瘤（MEOT）的价值。方法 对43例上皮性卵巢肿瘤患者[包括29例MEOT （MEOT组）和14例BEOT （BEOT组）]行多b值DWI扫描,分别计算常规DWI参数（ADC）、体素内不相干运动（IVIM）模型参数（IVIM-D、IVIM-D^*及IVIM-f）及扩散峰度成像（DKI）参数（DKI-D、DKI-K）值,并比较2组间各参数差异。绘制ROC曲线,评价各参数鉴别诊断BEOT与MEOT的效能,分析观察者间和观察者内一致性。结果 BEOT组ADC值、IVIM-D值、IVIM-f值及DKI-D值均高于MEOT组,而DKI-K值低于MEOT组（P均<0.05）。2组IVIM-D^*值差异无统计学意义（P=0.133）。DKI-K值鉴别诊断BEOT与MEOT的效能最高,ROC曲线下面积为0.900（P<0.001）,敏感度和特异度分别为85.71%和86.21%。观察者间和观察者内测量DWI各参数的一致性均非常好（ICC均>0.8）。结论 不同模型多b值DWI均有助于鉴别诊断BEOT与MEOT,DKI-K值的鉴别诊断效能最高。     

18F-FDG PET/CT诊断肝细胞癌及肝内胆管细胞癌

目的 探讨¹⁸F-FDG PET/CT诊断肝细胞癌（HCC）及肝内胆管细胞癌（ICC）的应用价值。方法 回顾性分析133例HCC患者（HCC组）和55例ICC患者（ICC组）的¹⁸F-FDG PET/CT资料,记录病灶最大标准化摄取值（SUV_max）,以病灶¹⁸F-FDG浓集水平高于周围正常肝组织为诊断恶性标准,比较2组原发灶¹⁸F-FDG PET/CT阳性率、SUV_max值、胆管扩张发生率、癌栓发生率、淋巴结转移发生率、远处转移发生率以及淋巴结转移、远处转移不同区域的发生率差异。结果 ICC组¹⁸F-FDG PET/CT阳性率（χ²=13.887）、SUV_max值（t=-4.139）、胆管扩张发生率（χ²=126.441）、淋巴结转移发生率（χ²=32.727）、远处转移发生率（χ²=30.964）、在各区域淋巴结转移及远处转移发生率均较HCC组高（P均< 0.05）,而癌栓发生率与HCC组差异无统计学意义（χ²=0.054,P=0.815）。结论 ¹⁸F-FDG PET/CT鉴别诊断HCC与ICC具有重要价值。HCC的SUV_max值低于ICC。ICC较HCC更易出现病灶周围胆管扩张、发生远处转移及合并淋巴结转移。     

R2*值预估肝细胞癌病理分级的可行性

目的 探讨增强T2^*加权血管成像（ESWAN）序列的R2^*值预估肝细胞癌（HCC）病理分级的可行性。方法 回顾性分析69例（共71个病灶）接受1.5T MR（含ESWAN序列）检查并经手术病理证实为HCC患者的影像资料,按照病理学分级分为3组,其中低分化组25个,中分化组25个,高分化组21个病灶。由2名观察者分别测量各组HCC实质区的R2^*值,检验2名观察者测量数据的一致性,并分析R2^*值与HCC病理级别的相关性,对不同级别HCC的R2^*值进行组间两两比较;采用ROC曲线评估R2^*值预估低级别HCC的效能并确定界值。结果 2名观察者测量各组数据的一致性很好（ICC>0.75）。R2^*值与HCC病理分级呈弱相关（r_s=0.493,P<0.001）,低、中和高分化组HCC的R2^*值分别为（30.57±9.95）Hz、（21.07±5.11）Hz和（19.08±4.83）Hz,低、中分化组间及低、高分化组间R2^*值差异有统计学意义（P均<0.001）,中、高分化组间差异无统计学意义（P=0.350）。应用R2^*值预估低分化HCC的曲线下面积（AUC）为0.816,以R2^*值=21.96 Hz为界值,敏感度为80.0%,特异度为73.9%。结论 R2^*值可作为MR非强化方式预估低分化HCC的定量指标。     

胆管细胞癌与不同分化程度肝细胞癌CEUS特征的对比研究

目的 比较肝内胆管细胞癌（ICC）和不同分化程度肝细胞癌（HCC）CEUS表现对ICC和不同分化程度HCC的鉴别诊断价值。方法 回顾性分析经病理证实的34例ICC（ICC组）和136例不同分化程度的HCC患者高、中、低分化（HCC组）的常规超声及CEUS表现,并评价CEUS始退时间对ICC的诊断效能。结果 ICC组在门静脉早期开始消退的比例（24/34,70.59%）均高于各HCC组,在门静脉中期开始消退的比例（0/34）和在门静脉晚期/延迟期开始消退的比例（4/34,11.76%）均低于中、高分化HCC组,差异均有统计学意义（P均<0.008）。低分化HCC组在门静脉中期开始消退的比例（16/41,39.02%）高于高分化HCC组（P<0.008）。CEUS诊断ICC的敏感度、特异度、阳性预测值、阴性预测值、准确率、阳性似然比及阴性似然比分别为82.35%（28/34）、91.18%（124/136）、70.00%（28/40）、95.38%（124/130）、89.41%（152/170）、9.4、0.2。ICC及低、中、高分化HCC组病灶CEUS始增时间分别为（13.03±3.49）s、（13.80±3.04）s、（14.89±4.12）s、（16.00±3.38）s,差异有统计学意义（F=4.369,P<0.05）,ICC组始增时间早于高分化HCC组（P<0.05）。结论 不同分化程度HCC和ICC的CEUS表现存在差异,CEUS对其鉴别诊断有一定的参考价值。     

体素内不相干运动扩散加权成像在肝细胞癌术前分级中的应用

目的 探讨应用体素内不相干运动扩散加权成像(IVIM DWI)对肝细胞癌(HCC)进行术前分级的可行性。方法 回顾性分析29例HCC患者的影像学资料及病理资料。以Edmondson-Steiner分级法为依据分为低级别组、高级别组, 均接受MRI及多b值DWI成像, 应用单双指数函数分别计算两组的标准ADC值、真实扩散系数(D值)、灌注相关扩散系数(D^*值)及灌注分数(f值)。组间比较采用非参数检验Mann-Whitney U, DWI参数预测HCC分级效能的比较采用ROC曲线分析。结果 低级别组12例, 高级别组17例。低级别组标准ADC值、D值、D^*值和f值分别为(1.29±0.27)×10^-3 mm²/s、(1.21±0.36)×10^-3 mm²/s、(40.20±7.79)×10^-3 mm²/s、(23.97±9.22)%, 高级别组分别为(0.90±0.25)×10^-3 mm²/s (0.75±0.20)×10^-3 mm²/s、(53.40±11.99)×10^-3 mm²/s、(32.24±12.66)%, 两组间标准ADC值、D值及D^*值的差异有统计学意义(P均 <0.05), f值差异无统计学意义(P >0.05)。应用标准ADC值、D值、D^*值鉴别诊断低级别与高级别HCC的曲线下面积依次为0.86、0.89、0.83;D值取阈值0.87×10^-3 mm²/s时的敏感度和特异度分别为90.0%和80.0%。结论 应用IVIM DWI可以于术前预测HCC的病理学分级。     

超高b值扩散加权成像及体素内不相干运动成像用于前列腺癌诊断

目的 观察超高b值扩散加权成像（DWI）及体素内不相干运动（IVIM）成像鉴别诊断前列腺癌（PCa）与前列腺增生（BPH）及预测PCa病理分级的价值。方法 收集55例接受前列腺IVIM-DWI（b=0、50、100、150、200、400、600、800、1 000、1 500、2 000 s/mm²）并经病理确诊为PCa（PCa组）或BPH（BPH组）患者，根据病理分级结果将PCa组分为低分亚组与高分亚组，比较组间及亚组间ADC值、D值、D^*值及f值差异，对差异有意义的参数绘制鉴别诊断PCa与BPH及预测PCa病理分级的ROC曲线，评估其诊断效能；分析PCa组各参数与Gleason评分的相关性。结果 共纳入44例，PCa组24例，BPH组20例，组间ADC值、D值差异均有统计学意义（t=-14.24、-10.87，P均<0.01），而ADC值（0.99）及D值（0.98）鉴别诊断PCa与BPH的AUC差异无统计学意义（Z=1.18，P=0.24）。PCa组内低、高分亚组的ADC值及D值差异均有统计学意义（t=2.28、3.86，P均<0.05），ADC值（0.76）及D值（0.88）预测PCa病理分级的AUC差异亦均有统计学意义（Z=2.23，P=0.02）；PCa组ADC值（r=-0.44）及D值（r=-0.56）与Gleason评分均呈负相关（P均<0.05）。结论 超高b值DWI与IVIM成像对PCa有一定应用价值。ADC值与D值鉴别诊断PCa与BPH的效能相当，而D值预测PCa病理级别的效能高于ADC值。     

扩散峰度成像模型与传统扩散加权成像单指数模型鉴别乳腺肿块良恶性的对比分析

目的 对比分析扩散峰度成像（DKI）模型与传统DWI单指数模型对乳腺良恶性肿块的鉴别诊断价值。方法 对78例乳腺肿块患者于术前行MR检查,包括常规平扫、传统DWI、DKI及动态对比增强（DCE）扫描。通过传统DWI单指数模型获得病灶的ADC值,通过DKI模型获得病灶的平均扩散峰度（MK）及平均扩散系数（MD）值。采用独立样本t检验比较乳腺良恶性肿块间ADC、MK、MD值的差异。以ROC曲线评价ADC、MK和MD值对乳腺恶性肿块的诊断效能。并采用χ²检验比较MK、MD、MK联合MD值的曲线下面积（AUC）与ADC值的AUC间的差异。结果 78例共87个病灶,其中良性病灶29个,恶性病灶58个。恶性病灶的ADC和MD值明显低于良性病灶（P均<0.001）,MK值明显高于良性病灶（P<0.001）。良性及恶性病灶的MD值均高于其ADC值（P均<0.001）。以ADC值诊断乳腺恶性肿块的敏感度、特异度、准确率分别为86.21%、89.66%、87.36%;MK值的敏感度、特异度、准确率分别为84.48%、96.55%、88.51%;MD值的敏感度、特异度、准确率分别为82.76%、93.10%、89.66%。MK值的AUC及MK联合MD值的AUC均为0.94（P<0.05）,且均高于ADC值的AUC（χ²=5.90,P=0.02）,而MD与ADC值的AUC差异无统计学意义（χ²=0.15,P=0.70）。结论 相对于传统DWI单指数模型,DKI模型更有利于乳腺肿块良恶性的鉴别。     

弥散张量成像诊断新生儿和婴儿胆道闭锁

目的 探讨弥散张量成像（DTI）对新生儿和婴儿胆道闭锁（BA）的诊断价值。方法 收集疑诊为BA或其他胆道疾病的患儿46例,以手术探查、腹腔镜探查、术中造影、病理检查或临床治疗结果作为金标准,将患儿分为BA组与非BA组（non-BA组）。对所有患儿应用1.5T MR扫描仪,采用单次激发自旋回波平面成像DTI序列（b值为1000 s/mm²）行肝脏扫描,经后处理获得平均扩散系数（AvgDC）图及FA图,测量AvgDC值及FA值。结果 46例中,BA组24例,non-BA组22例,BA组的AvgDC值显著低于non-BA组［（1.27±0.16）×10^-3 mm²/s vs （1.43±0.15）×10^-3 mm²/s,P=0.001)］。在BA组中,不同肝脏纤维化分级患儿间AvgDC值、FA值的差异均无统计学意义（P>0.05）;INF1~INF3级炎症分级患儿AvgDC值逐渐降低,但差异无统计学意义（F=2.15, P=0.14）,FA值差异有统计学意义（F=5.51, P=0.01）。应用AvgDC、FA值诊断BA的ROC曲线下的面积分别为0.80±0.07、0.60±0.09;AvgDC界限值为1.33×10^-3 mm²/s时,诊断敏感度为75.00%（18/24）,特异度为77.27%（17/22）。结论 DTI的AvgDC值可用于诊断新生儿和婴儿BA,但其诊断敏感度与特异度仍有待提高。     

MR脂肪抑制T2WI联合弥散加权成像与增强MRI鉴别乳腺黏液癌与黏液样纤维腺瘤

目的 对比观察MR脂肪抑制（FS）-T2WI （FS-T2WI）联合弥散加权成像（DWI）与增强MRI鉴别乳腺黏液癌（MBC）与乳腺黏液样纤维腺瘤（MFA）的价值。方法 回顾性分析经术后病理证实的14例MBC （MBC组）与22例乳腺MFA （MFA组）,比较组间FS-T2WI信号强度（SI）指数、DWI-表观弥散系数（ADC）、强化特点及时间信号强度曲线（TIC）等MRI表现差异。针对FS-T2WI联合DWI及增强MRI参数以二元logistic回归分析拟合回归方程,绘制受试者工作特征（ROC）曲线,计算曲线下面积（AUC）,评估2种回归方程鉴别MBC与乳腺MFA的效能。结果 组间FS-T2WI信号SI指数（Z=3.780,P<0.001）、DWI-ADC （t=4.230,P<0.001）、强化均匀与否（P=0.006）、早期强化方式（P<0.001）、强化填充方式（P<0.001）及TIC类型（P=0.001）差异均有统计学意义,延迟期强化方式差异无统计学意义（P=0.062）。基于FS-T2WI联合DWI参数建立回归方程如下：Logit （P）=－10.434+0.003×ADC+0.748×FS-T2WI SI指数;基于增强MRI参数建立回归方程Logit （P）=31.666+0.287×强化均匀与否-18.319×早期强化方式+19.945×强化填充方式-36.591×延迟期强化方式+20.225×TIC类型。上述2个回归方程鉴别MBC与乳腺MFA的AUC （Z=1.890,P=0.059）、敏感度（χ²=1.050,P=0.305）、特异度（χ²=1.100,P=0.294）和准确率（χ²=0.660,P=0.416）差异均无统计学意义。结论 FS-T2WI联合DWI可鉴别诊断MBC与乳腺MFA,其诊断效能与增强MRI相当。     

IVIM-DWI鉴别诊断肝细胞癌和肝局灶性结节增生

目的 探讨体素内不相干运动扩散加权成像（IVIM-DWI）鉴别肝细胞癌（HCC）与肝局灶性结节增生（FNH）的价值。方法 对407例临床疑似HCC或FNH的患者行常规上腹部MR平扫、动态增强及IVIM-DWI扫描,60例患者（40例HCC,20例FNH）入组。IVIM采用单、双指数模型获得表观扩散系数（ADC）、慢速表观扩散系数（D）、快速表观扩散系数（D^*）及快速扩散成分所占比例（f）。结果 FNH组的ADC、D、D^*及f值分别为（1.60±0.25）×10^-3mm²/s、（1.12±0.17）×10^-3mm²/s、（44.89±18.23）×10^-3mm²/s和（34.80±9.68）%;HCC组分别为（1.32±0.21）×10^-3mm²/s、（0.82±0.21）×10^-3mm²/s、（49.82±20.11）×10^-3mm²/s和（28.72±13.84）%。2组间的ADC、D值差异有统计学意义（P均<0.001）,而D^*、f值差异无统计学意义（P>0.05）。D值相应ROC曲线下面积为0.90,以0.96×10^-3mm²/s为阈值诊断HCC的敏感度、特异度分别为84.44%、90.02%。结论 IVIM-DWI有助于鉴别诊断HCC和FNH,其中双指数模型计算的D值诊断效能更高。     

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.