采用神经血管线圈和体线圈测量颈部良性淋巴结表观弥散系数值的稳定性

目的 观察神经血管线圈和体线圈接收信号测量的颈部良性淋巴结的ADC值与指数化ADC(eADC)值是否存在差异。 方法 对15名健康志愿者于同日内分别采用8通道神经血管线圈和体线圈行颈部DWI扫描,b值均取0、800 s/mm²,对比双侧(30个)及左右分侧(各15个)良性淋巴结DWI图、ADC图及eADC图特点,分别测量两种线圈测量出的淋巴结ADC及eADC值,并进行比较。 结果 对15名受检者采用两种线圈扫描均获得可测量ADC的图像。神经血管线圈测量出的淋巴结平均ADC值为(0.892±0.165)×10^-3 mm²/s,平均eADC值为(0.425±0.068)×10^-3 mm²/s;体线圈测量出的淋巴结的平均ADC值为(0.857±0.142)×10^-3 mm²/s,平均eADC值为(0.432±0.057)×10^-3 mm²/s。采用两种线圈所获双侧或左右分侧淋巴结的ADC值、eADC值之间差异均无统计学意义(P>0.05)。 结论 采用神经血管线圈或体线圈接收信号对颈部良性淋巴结DWI ADC值的测量无影响。     

扩散加权成像对前列腺外周带炎症和肿瘤T2低信号的鉴别作用

目的 通过磁共振DWI探讨前列腺炎和前列腺癌患者前列腺外周带T2低信号区ADC值的变化特点,定量评价DWI在鉴别前列腺外周带T2低信号区炎症和肿瘤中的价值。方法 收集103例MRI显示为前列腺外周带T2信号减低的初诊患者,根据超声引导下穿刺活检结果分为前列腺炎组(50例)和前列腺癌组(53例),测定T2低信号区的平均ADC值和最低ADC值;采用独立样本t检验对两组ADC值进行比较。结果 前列腺炎组平均ADC值为(1.33±0.20)×10^－3 mm²/s,前列腺癌组平均ADC值为(0.86±0.12)×10^－3 mm²/s,差异有统计学意义(t=14.70,P＜0.05)。前列腺炎组最低ADC值为(1.22±0.19)×10^－3 mm²/s,前列腺癌组最低ADC值为(0.68±0.15)×10^－3 mm²/s(t=16.45,P＜0.05)。结论 应用DWI定量评价和鉴别外周带T2低信号前列腺炎和前列腺癌是可行的。     

ADC值鉴别甲状腺结节的良恶性

目的 探讨MR DWI的ADC值鉴别诊断甲状腺良恶性结节的价值。方法 回顾性分析27例(40个病灶)经病理证实的甲状腺结节患者资料,术前均接受常规MR、脂肪抑制增强扫描明确病变实性部分;单次激发自旋平面回波成像(SS SE-EPI)DWI扫描(b值取0、500 s/mm²),测量实性部分的平均ADC值。依据病理结果将结节分为良性组及恶性组,比较其ADC值差异,绘制ROC曲线,确定诊断阈值,评价筛检效能。结果 40个结节中,甲状腺恶性结节15个,平均ADC值为(1.22±0.27)×10^－3 mm²/s,95%可信区间(1.07~1.37)×10^－3 mm²/s;良性结节25个,平均ADC值为(2.20±0.40)×10^－3 mm²/s,95%可信区间(2.04~2.37)×10^－3 mm²/s。恶性组平均ADC值显著低于良性组(P＜0.05)。ROC曲线下面积为0.98、诊断阈值1.49×10^－3 mm²/s时,诊断敏感度为86.70%,特异度为100%,准确率为95.00%。结论 甲状腺良恶性结节的ADC值显著不同,MR DWI可鉴别甲状腺结节的良恶性。     

磁共振扩散加权成像评估乳腺癌新辅助化疗疗效

目的 探讨MR DWI评估乳腺癌新辅助化疗(NAC)疗效的价值。方法 对36例经穿刺病理证实的乳腺癌患者在NAC前、后不同疗程末行DWI。依据手术病理结果分为有效组和无效组,比较有效组和无效组化疗前ADC值的差异及化疗前、后不同疗程肿瘤ADC值的差异。结果 36例中,有效组(24例)化疗前肿瘤平均ADC值为(0.98±0.18)×10^-3 mm²/s,无效组(12例)化疗前肿瘤平均ADC值为(0.95±0.15)×10^-3 mm²/s(t＝0.694,P＝0.411)。有效组化疗后ADC值升高,化疗前肿瘤ADC值与化疗第2~8个疗程后比较差异均有统计学意义;无效组化疗前、后肿瘤ADC值差异无统计学意义。有效组化疗前20例患者的对侧正常乳腺组织平均ADC值为(1.98±0.30)×10^-3 mm²/s,化疗4个疗程后12例患者的对侧正常乳腺组织平均ADC值为(1.96±0.28)×10^-3 mm²/s,差异无统计学意义。结论 化疗有效组乳腺癌ADC值较化疗前升高;根据ADC值可以早期预测乳腺癌NAC疗效。     

磁共振弥散加权成像动态监测肿瘤血管靶向治疗的疗效

目的 探讨磁共振DWI监测肿瘤血管靶向治疗后动态变化的可行性。方法 选取新西兰大白兔15只建立兔肌肉VX2肿瘤模型(共30个肿瘤)。分别于肿瘤血管靶向治疗(CA-4-P,20 mg/kg体质量)前及治疗后1、4、8、12天进行常规、增强MRI及DWI,比较相邻时间点肿瘤整体、肿瘤中心、周边及肌肉组织的ADC值动态变化,并与病理表现进行对照。结果 肿瘤血管靶向治疗前(MR基线扫描),肿瘤整体、肿瘤中心、周边及肌肉组织的ADC值分别为(1.33±0.16)×10^－3 mm²/s、(1.30±0.23)×10^－3 mm²/s、(1.19±0.31)×10^－3 mm²/s及(1.66±0.13)×10^－3 mm²/s;镜下见肿瘤细胞生长旺盛。治疗后1天,肿瘤中心ADC值较MR基线扫描减低(P＜0.05);镜下见肿瘤细胞肿胀,排列松散,靠近肿瘤中心处可见肿瘤细胞破裂、核固缩。治疗后4天,肿瘤整体、肿瘤中心及周边ADC值较治疗后1天增高(P均＜0.05);镜下可见大范围肿瘤坏死。治疗后8天,肿瘤中心ADC值较治疗后4天增高(P＜0.05);镜下见肿瘤中心坏死更加彻底。治疗后12天,肿瘤整体及肿瘤周边ADC值较治疗后8天减低(P均＜0.05);镜下可见肿瘤周边新生的肿瘤组织。结论 DWI能准确反映兔肌肉VX2肿瘤模型CA-4-P给药后肿瘤组织的动态变化,可作为理想的肿瘤血管靶向治疗监测和疗效评价手段。     

DWI鉴别诊断实质性肝脏肿瘤的价值

目的 探讨DWI鉴别诊断实质性肝脏良性与恶性肿瘤的价值。 方法 回顾性分析经病理证实的7例肝腺瘤、14例肝局灶性增生(FNH)及32例肝脏恶性肿瘤患者(25例肝癌和7例转移瘤)的DWI定量分析结果,比较肝脏FNH和腺瘤与肝脏恶性肿瘤ADC值的差异。 结果 7例肝腺瘤9个病灶的平均ADC值为(1.05±0.28)×10^-3 mm²/s,14例FNH 18个病灶的平均ADC值为(1.13±0.46)×10^-3 mm²/s,32例肝脏恶性肿瘤49个病灶的平均ADC值为(0.96±0.29)×10^-3 mm²/s(b＝800 s/mm²)。FNH、肝腺瘤与肝脏恶性肿瘤的平均ADC值之间差异无统计学意义(P均>0.05)。 结论 ADC值对实质性肝脏良性肿瘤(FNH和肝腺瘤)与肝脏恶性肿瘤的鉴别无帮助。     

DWI诊断小儿幕下脑肿瘤

目的 评价扩散加权成像(DWI)和表观扩散系数(ADC)值诊断及鉴别诊断小儿幕下脑肿瘤的价值。方法 58例经病理证实的幕下脑肿瘤患儿均接受常规MR平扫、增强和DWI扫描,并测量实质病变的ADC值。结果 髓母细胞瘤25例,ADC均值(6.73±1.55)×10^-4 mm²/s;星形细胞瘤(Ⅰ~Ⅱ级)24例,ADC均值(14.80±2.61)×10^-4 mm²/s;室管膜瘤8例,ADC均值(11.08±1.60)×10^-4 mm²/s;少突胶质瘤1例,ADC均值(15.10±2.73)×10^-4 mm²/s。对前三种肿瘤实质部分ADC值进行方差分析(F检验)和t检验,其ADC值差异有统计学意义(P<0.01)。结论 DWI及ADC值可评估小儿幕下脑肿瘤实质病变,是术前诊断及鉴别诊断后颅窝肿瘤的简单可靠的检查方法,对鉴别诊断髓母细胞瘤与星形细胞瘤有明显优势。     

大范围扩散加权成像鉴别诊断椎体良恶性病变

目的 探讨MR大范围扩散加权成像(DWI)对椎体良、恶性病变的鉴别诊断价值。方法 回顾性分析经过病理或临床证实的75例患者的常规MR平扫及大范围DWI资料。良性组42例,其中单纯性骨折24例,血管瘤12例,结核6例;恶性组33例,转移瘤19例,骨髓瘤8例,骨肉瘤3例,白血病2例,骨淋巴瘤1例。分析病变与正常椎体(对照组)大范围DWI信号特点,并测定ADC值,比较良性组、恶性组及对照组之间ADC值的差异。结果 良性组、恶性组及对照组的ADC值分别为(1.58±0.54)×10^－3 mm²/s、(0.98±0.35)×10^－3 mm²/s、(0.37±0.16)×10^－3 mm²/s。病变组的ADC值均高于对照组(P均＜0.001);良性组ADC值高于恶性组(P＜0.001)。结论 大范围DWI序列可以全面显示椎体病变范围及程度。定量分析ADC值对鉴别脊椎良、恶性病变具有一定价值,大范围DWI成像可作为椎体病变MR常规检查序列之一。     

DWI定量测量诊断宫颈癌

目的 探讨DWI定量测量诊断宫颈癌的价值。方法 收集经手术病理证实为宫颈癌的患者93例,包括鳞癌66例(高分化1例,中分化56例,低分化9例)及腺癌27例(高分化3例,中分化21例,低分化3例),宫颈正常者20例。对所有受检者均行常规MR及DWI扫描,测量ROI的ADC值,并进行统计学分析。结果 宫颈癌的ADC值[(1.05±0.24)×10^-3 mm²/s]低于正常宫颈[(1.87±0.22)×10^-3 mm²/s;t=-14.08,P<0.05]。宫颈鳞癌的ADC值[(0.97±0.13)×10^-3 mm²/s]低于宫颈腺癌[(1.26±0.31)×10^-3 mm²/s;t=-4.79,P<0.05]。中分化宫颈鳞癌ADC值[(0.98±0.14)×10^-3 mm²/s]高于低分化宫颈鳞癌[(0.88±0.14)×10^-3 mm²/s;t=2.31,P<0.05]。以ADC<1.59×10^-3 mm²/s诊断宫颈癌时,敏感度为95.70%,特异度为100%。结论 DWI对宫颈癌的诊断具有较高价值,ADC值可鉴别宫颈鳞癌与宫颈腺癌,且可评价宫颈鳞癌的分化程度。     

弥散加权成像观察胼胝体发育异常胎儿脑发育

目的 采用弥散加权成像(DWI)观察胼胝体发育异常胎儿脑组织发育。方法 回顾性分析100名接受产前胎儿MR检查的单胎妊娠孕妇资料,根据胎儿胼胝体发育异常与否分为异常组(n=25)和正常组(n=75),测量双侧额叶、顶叶、颞叶、枕叶、小脑半球、半卵圆中心及脑桥表观弥散系数(ADC)并比较其组间差异,分析其随孕周变化规律。结果 100胎左、右侧脑区ADC差异均无统计学意义(P均＞0.05)。异常组与正常组胎儿颞叶ADC差异有统计学意义(P＜0.05),且顶叶ADC均最高(1.85×10^－3 mm²/s、1.87×10^－3mm²/s)而脑桥ADC均最低(1.32×10^－3 mm²/s、1.31×10^－3mm²/s)。异常组胎儿各脑区ADC与孕周均无明显相关性(P均＞0.05)。正常组胎儿额叶、顶叶、颞叶、枕叶及半卵圆中心ADC与孕周存在曲线相关(r=0.50、0.26、0.51、0.25、0.33,P均＜0.05),小脑半球及脑桥ADC与孕周呈线性负相关(r=－0.31、－0.23,P均＜0.05)。结论 胼胝体发育异常胎儿颞叶ADC高于正常胎儿, 且其各脑区ADC均与孕周无明显相关性。     

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.