磁共振弥散加权成像对不同病理类型脑膜瘤的诊断价值

目的 探讨DWI及ADC值对脑膜瘤分型及分级的价值。方法 回顾性分析经手术病理证实为脑膜瘤的109例患者,于Functool图像后处理工作站上测量肿瘤实质区、瘤周水肿区及对侧正常脑白质ADC值,计算相对ADC值（rADC）。比较不同病理亚型及分级脑膜瘤的DWI信号特征及ADC值的差异。结果 不同病理亚型脑膜瘤DWI信号差异无统计学意义（χ2=17.86,P=0.12）,不同病理分级脑膜瘤DWI信号差异亦无统计学意义（χ2=4.95,P=0.29）。良恶性脑膜瘤肿瘤实质rADC(rADCt)差异有统计学意义（t=2.57,P=0.01）,而二者肿瘤实质ADC值（ADCt）、瘤周水肿ADC值（ADCe）及瘤周水肿rADC值（rADCe）差异均无统计学意义（P均＞0.05）。血管瘤型脑膜瘤ADCt及rADCt值高于其他各病理亚型（P均＜0.05）;间变型脑膜瘤ADCt及rADCt低于纤维型及脑膜皮细胞型（P均＜0.05）。结论 rADCt可用以鉴别脑膜瘤良恶性;ADCt及rADCt值对鉴别诊断脑膜瘤病理亚型具有一定的临床价值。     

常规MRI及DWI诊断非典型性原发性中枢神经系统淋巴瘤

目的 探讨常规MRI联合DWI诊断非典型性原发性中枢神经系统淋巴瘤（PCNSL）的价值。方法 分析14例经病理证实的非典型性PCNSL患者的常规MRI及DWI特征,测量肿瘤实质区、瘤周近侧水肿区、瘤周远侧水肿区、对侧正常脑白质区的ADC值,并计算相对ADC（rADC）值,比较不同区域ADC值和rADC值的差异。结果 14例PCNSL中,单发12例,多发2例,共20个病灶,其中9个病灶位于非常规好发部位,包括脑浅表部位5个,脑干脑桥区、小脑半球、鞍区和第三脑室各1个。非典型性PCNSL的MRI表现包括3个病灶出现囊变、坏死区,1个病灶可见内部出血,7个病灶呈环形强化,3个病灶呈不规则片状强化。肿瘤实质区的ADC值为（0.70±0.15）×10^-3mm²/s,rADC值为0.86±0.14,均低于瘤周近侧和远侧水肿区（P均<0.05）,瘤周近侧水肿区ADC值高于远侧瘤周水肿区（P<0.05）。结论 对比常规MRI及DWI中肿瘤实质区、瘤周近侧水肿区、瘤周远侧水肿区的ADC、rADC值的差异,有助于诊断和鉴别诊断PCNSL。     

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。     

3.0T MR ADC值和相对ADC值对颈部转移性淋巴结的诊断价值

目的 探讨3.0T MR ADC值和相对ADC值(rADC值)对颈部转移性淋巴结的诊断价值。方法 对23例颈部淋巴结转移患者(病例组)和40名健康志愿者(对照组)行MR检查,测量对照组脊髓、肌肉、颌下腺和腮腺的ADC值并对比分析,为rADC选取最佳参照部位。测量所有受检者淋巴结ADC值,并计算其rADC值,比较转移性淋巴结与正常淋巴结ADC值与rADC值有无差异。结果 ①头半棘肌的变异系数最低,腮腺的观察者间一致性最好;②转移性淋巴结(n=28)ADC值和rADC值均低于正常淋巴结(n=57,P均<0.05);③b=600 s/mm²时,DWI鉴别诊断转移性淋巴结与正常淋巴结的ADC阈值为0.924×10^-3 mm²/s,敏感度90.9%,特异度86.4%;以头半棘肌为参照的rADC阈值为0.489,敏感度86.4%,特异度86.4%;以腮腺为参照的rADC阈值为0.944,敏感度86.4%,特异度81.8%。结论 ADC值及rADC值均有助于区分颈部转移性淋巴结与正常淋巴结;rADC值的诊断价值未较ADC值提高。     

读出方向分段采样DWI鉴别舌良恶性病变

目的 探讨读出方向分段采样（RESOLVE）DWI对舌良恶性病变的鉴别诊断价值。方法 回顾性分析经临床及病理证实的120例舌部病变患者的资料,患者术前均接受常规MR检查及RESOLVE DWI。测量病变的ADC值,比较舌良恶性病变间ADC值的差异,应用ROC曲线评价ADC值的诊断舌良恶性病变的价值。结果 120例舌部病变均单发,其中良性病变56例,恶性病变64例。良性病变ADC值为（1.81±0.45）×10^-3 mm²/s,恶性病变为（1.02±0.24）×10^-3 mm²/s,二者差异有统计学意义（t''=12.21,P<0.001）。以ADC值诊断舌部良恶性病变的ROC曲线AUC为0.976（P<0.001）,以ADC值=1.25×10^-3 mm²/s为临界值,诊断舌良恶性病变的敏感度为94.64%（53/56）,特异度为93.75%（60/64）。结论 RESOLVE DWI鉴别诊断舌良恶性病变具有一定参考价值。     

体素内不相干运动弥散加权成像与弥散加权成像鉴别诊断甲状腺良恶性结节：Meta分析

目的 采用Meta分析方法评价体素内不相干运动弥散加权成像（IVIM-DWI）及弥散加权成像（DWI）鉴别诊断甲状腺良恶性结节的效能。方法 检索Cochrane Library、Embase、PubMed、中国知网、万方医学网及中国生物医学文献数据库,根据标准筛选建库至2020年5月IVIM-DWI及DWI参数鉴别诊断甲状腺良恶性结节相关文献,提取相关资料,以Stata 12.0和Meta-disc 1.4软件进行Meta分析。结果 纳入文献17篇文献,包括12篇英文、5篇中文文献,787个良性、634个恶性共1 421个甲状腺结节;根据真实扩散系数（D）值诊断的合并敏感度及特异度、阳性似然比及阴性似然比分别为0.85（0.71,0.92）、0.90（0.85,0.94）、8.77（5.29,14.55）及0.17（0.09,0.34）;表观扩散系数（ADC）的相应合并值分别为0.88（0.85,0.91）、0.90（0.85,0.94）、8.86（5.66,13.88）及0.13（0.10,0.16）,其AUC与D值差异无统计学意义（Z=-0.299,P=0.385）。异质性检验结果显示文献中ADC的合并特异度及D值的合并敏感度存在异质性。ADC值及D值诊断甲状腺良恶性结节无明显阈值效应（r=-0.113、-0.145,P=0.676、0.784）。分析研究类型、设备场强、b值、感兴趣区等因素,均未发现异质性的明确来源。结论 以D值及ADC值诊断甲状腺良恶性结节的效能相当,但IVIM-DWI参数可提供更多相关信息,且结果稳定性、可重复性更佳。     

DWI及动态增强MRI鉴别诊断舌良恶性病变

目的 评价DWI及动态增强MRI鉴别诊断舌良恶性病变的价值。方法 对75例经病理确诊的舌部病变患者行DWI和动态增强MRI。测量并比较舌良恶性病变病灶ADC值,绘制ROC曲线分析ADC值诊断舌恶性肿瘤效能;比较舌良恶性病变时间-信号强度曲线（TIC）分型差异。结果 舌恶性病变的ADC值[（1.12±0.21）×10^-3mm²/s]明显低于良性病变[（1.84±0.47）×10^-3mm²/s,P<0.001）;以ADC值1.30×10^-3mm²/s为阈值,诊断舌恶性病变的敏感度、特异度和准确率分别为90.70%、93.75%和92.00%,ROC曲线下面积为0.957。良性病变（除外8例囊肿）中19例（19/24,79.17%）TIC为Ⅲ型,5例（5/24,20.83%）为Ⅱ型;恶性病变中39例（39/43,90.70%）TIC为Ⅰ型,4例（4/43,9.30%）为Ⅱ型。结论 舌良恶性病变DWI和动态增强MRI具有不同特征,ADC值和TIC曲线有助于鉴别诊断两者。     

磁共振扩散加权成像监测骨肉瘤对诱导和新辅助化疗的反应

目的 探讨应用DWI监测骨肉瘤诱导和新辅助化疗反应的价值。方法 收集经病理证实的26例骨肉瘤患者,所有患者化疗前后均接受常规MR及DWI扫描。根据化疗反应情况分为反应差组（n=12,肿瘤坏死范围≤90%）和反应好组（n=14,肿瘤坏死范围>90%）。测量并比较治疗前后骨肿瘤的ADC值、肿瘤体积及其变化率。结果 化疗前及化疗后,反应好组与反应差组间肿瘤体积和ADC值差异均无统计学意义（P均>0.05）。两组化疗前后肿瘤体积变化率差异无统计学意义（P=0.05）,而ADC值变化率的差异有统计学意义（P<0.001）。结论 应用DWI测定化疗前后骨肉瘤ADC值改变率有助于监测肿瘤对诱导化疗和新辅助化疗的反应。     

体素内不相干运动双指数模型评价乳腺肿块样病变

目的 应用体素内不相干运动(IVIM)双指数模型探讨真性弥散系数(D)、与灌注相关的假性弥散系数(D^*),灌注分数(f)在诊断乳腺肿块样病变诊断中的应用价值。方法 收集经病理证实的乳腺恶性肿块48例(恶性组)、良性肿块26例(良性组)及正常体检者19名(对照组),均行常规MRI检查及多b值的弥散加权成像检查。比较3组间D值、f值、D^*值及ADC值的差异,采用ROC曲线评估各个指标对乳腺良恶性肿块样病变的诊断效能。结果 对照组、良性组及恶性组间D、f、D^*及ADC值的差异均有统计学意义(P均<0.01)。良性组D值低于对照组、且高于恶性组(P均<0.01);恶性组f值高于对照组及良性组(P均<0.01),而对照组与良性组间差异无统计学意义(P=0.14);良性组D^*值低于对照组、高于恶性组(P均<0.01);良性组ADC值低于对照组、高于恶性组(P均<0.01)。恶性组的D值显著低于ADC值(P<0.01)。分析采用各DWI参数鉴别诊断乳腺恶性肿块样变的ROC曲线,D值具有较高的诊断效能,其次依次为ADC值,f值及D^*值,曲线下面积(AUC)依次为0.95、0.90、0.87、0.75。结论 IVIM双指数模型能够真实反映乳腺肿块样病变水分子的弥散情况,尤其是D值对乳腺病变良恶性的鉴别诊断具有重要的参考意义。     

扩散加权成像鉴别诊断鼻咽癌和鼻咽部淋巴瘤

目的 探讨DWI鉴别诊断鼻咽癌（NPC）及鼻咽部淋巴瘤（NPL）的价值。方法 回顾性分析经病理证实的22例NPC和27例NPL的 平扫、增强MRI及DWI图像,对比分析两者的平均ADC值和病灶与未受侵翼外肌ADC值的比值（rADC值）,应用ROC曲线分析以ADC值、rADC值鉴别诊断NPC与NPL的效能。结果 NPC与NPL均于T1WI呈等或稍低信号、T2WI呈稍高信号。NPC于DWI（b=1000 s/mm²）上呈稍高信号、ADC图上呈等低信号,NPL于DWI（b=1000 s/mm²）上呈高信号、ADC图上呈低信号。NPC组ADC值为（842.34±94.66）×10^-6 mm²/s、rADC值为0.74±0.08。NPL组ADC值为（652.15±83.47）×10^-6 mm²/s、rADC值为0.56±0.08。两组病灶ADC值、rADC值的差异均具有统计学意义（P均<0.001）。应用ADC值鉴别NPC与NPL的曲线下面积为0.943,最佳鉴别阈值为736.5×10^-6 mm²/s,敏感度为90.9%,特异度为85.2%;应用rADC值进行鉴别的曲线下面积为0.951,最佳鉴别阈值为634.0×10^-6 mm²/s,敏感度为95.5%,特异度为81.5%。结论 DWI、ADC值及rADC值有助于鉴别诊断NPC与NPL。     

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.