一种改进UNet++网络用于检测黑色素瘤皮肤病变

目的 探究基于改进UNet++网络的图像分割算法用于分割黑色素瘤皮肤病变图像的价值。方法 构建引入软注意力门和以Tversky-Focal Loss（TFL）函数为损失函数的UNet++网络优化结构——AT-UNet++网络，并将其在国际皮肤成像协作组织（ISIC）挑战2016和2017训练集中训练。计算训练好的AT-UNet++网络与U-Net网络、UNet++网络的逐像素分割精度（ACC）、DIC相似系数（DIC）和Jaccard相似指数（JAI），对以TFL函数为损失函数的UNet++网络和引入软注意力门的UNet++网络在ISIC挑战2016和2017测试集上进行指标评估；比较ISIC挑战2016与2017竞赛排名前五名的参赛队伍模型与AT-UNet++网络的指标参数。结果 在ISIC挑战2016测试集上，AT-UNet++网络逐的ACC、DIC和JAI较UNet++网络分别提高3.36%、4.15%和3.95%，在2017测试集分别提高2.65%、5.01%及4.39%。结论 AT-UNet++网络的各项评价指标较其他模型均有不同程度提高。     

不同翻转角双回波稳态序列MRI评价膝关节骨性关节炎软骨损伤

目的 评估不同翻转角（FA）三维双回波稳态（3D-DESS）序列MRI对评价膝关节骨性关节炎软骨损伤的价值。方法 收集25例单侧膝关节疼痛患者，以FA 30°、60°及90° 3D-DESS序列采集膝关节MRI，评估每例患者髌骨（Pat）、股骨滑车（Tro）、股骨外侧髁（LFC）、股骨内侧髁（MFC）、胫骨外侧平台（LTP）及胫骨内侧平台（MTP）6个软骨情况，根据结果分为软骨损伤阳性（Ⅱ~Ⅳ级）和阴性（0、Ⅰ），对图像评价软骨损伤的诊断信心进行评分。以关节镜检查结果为标准，分析MRI结果与其的一致性。比较不同FA图像的诊断信心评分。结果 对于Pat、Tro、MFC、LFC、MTP、LTP，FA 90° 3D-DESS图像的结果与关节镜结果一致性较好（Kappa＝1.00、0.84、1.00、0.81、0.97、0.91，P均<0.01），但显示正常软骨结构欠佳；FA 60° 3D-DESS图像一致性较好或一般（Kappa＝0.87、0.61、0.81、0.74、0.73、0.68，P均<0.01），周围骨质及软组织显示较好；FA 30° 3D-DESS图像一致性一般或差（Kappa＝0.47、0.38、0.50、0.30、0.32、0.23，P均<0.01），但可清晰显示软骨结构。FA 30°图像诊断信心评分低于FA 60°（P均<0.05）及FA 90°图像（P均<0.01），FA 60°图像诊断信心评分低于FA 90°图像（P均<0.05）。结论 FA 90° 3D-DESS图像显示软骨损伤最佳，FA 30°清晰显示软骨形态及结构，而FA 60°能兼顾周围骨质及软组织，临床中应根据检查目的选择合适的FA。     

T2* mapping定量评估新兵奔袭集训后胫股关节软骨变化

目的 观察T2^* mapping定量评估新兵奔袭集训后胫股关节软骨早期变化的价值。方法 对22名新入伍健康男兵于奔袭集训前后分别采集右侧膝关节MRI，将关节软骨分为股骨内侧髁（MFC）承重区与非承重区、股骨外侧髁（LFC）承重区与非承重区、胫骨内侧平台（MTP）、胫骨外侧平台（LTP）6个区域，并将各区域分为浅层及深层，比较集训前各区域浅层与深层软骨T2^*值、集训前后各区域软骨T2^*值差异，分析集训前后各区域软骨T2^*值的变化百分率。结果 集训前胫股关节各区域软骨浅层T2^*值均高于深层（P均<0.05）；集训后LFC承重区、MFC承重区浅层、LTP浅层、MTP软骨T2^*值均明显高于集训前（P均<0.05）；集训前后各区域软骨T2^*值变化百分率差异有统计学意义（F=3.66，P<0.05）。结论 T2^* mapping可无创定量评估新兵奔袭集训后胫股关节软骨早期变化。     

股骨髋臼撞击征关节镜手术后磁共振成像结果与疼痛的关系研究

目的 探讨股骨髋臼撞击征（FAI）关节镜手术后磁共振成像（MRI）结果与疼痛的关系。方法 前瞻性地连续募集计划行关节镜手术的FAI患者42例（43个髋关节）。采用3.0T MRI获取术前和术后MRI图像。采用髋关节残疾与骨关节炎结果评分（HOOS）评估疼痛变化情况。采用术后MRI图像评估髋关节成形术、股骨成形术、软骨和盂唇修复术、骨髓水肿、软骨下囊肿、软骨缺陷、盂唇撕裂、囊部缺陷和渗出情况,并分析最佳检测方位。结果 髋臼清理术长度增加与HOOS改善有关（OR＾：-2.07,95%CI：-3.53～-0.62,P = 0.008）,而其他成像结果与HOOS改善无相关性。股骨成形术和关节囊改变斜轴位检测效果最好,而髋臼成形术、软骨和盂唇修复术矢状位检测效果最好。MRI反映盂唇修复术后变化的敏感性和特异性均为100.0%,反映股骨成形术后变化的敏感性为97.7%。MRI反映髋臼成形术后变化的敏感性和特异性分别为83.3%和75.0%。MRI反映软骨修复术后变化的敏感性和特异性分别为75.0%和54.3%。结论 关节镜下髋臼成形术与术后疼痛相关。     

膝关节术后粘连MRI表现及临床特点

目的 观察膝关节术后关节粘连的MRI征象及其临床特点。方法 回顾性分析27例接受关节镜下膝关节手术后再次经关节镜证实存在膝关节粘连患者,观察其MRI表现及临床特点。结果 膝关节术后关节粘连MRI表现为膝关节腔内不同程度滑膜增厚,T1WI呈低信号,脂肪饱和(FS)质子密度(PD)WI呈中-高信号,其内可见多发条带状T2WI低信号,关节腔内无或仅见少量积液。关节镜及MRI示膝关节术后关节粘连可累及髌上囊(81.48%,22/27)、髌下脂肪垫(77.78%,21/27)、内外侧隐窝(51.85%,14/27)及髁间窝(22.22%,6/27);且多伴(23/27,85.19%)不同程度关节软骨损伤,常累及髌骨软骨及滑车软骨。结论 膝关节术后关节粘连多发生于术后中晚期,好发于髌上囊和髌下脂肪垫,多伴软骨损伤,特别是髌骨软骨和滑车软骨;其MRI特征性表现为不同程度滑膜增厚,FS PDWI呈中-高信号,内见多发条带状T2WI低信号,关节腔内无或仅见少量积液。     

髌软骨T2-mapping成像:MRI正常与退变软骨的差异

目的 探讨1.5T MRI 0级髌软骨T2值的区域差异及其与性别、年龄间的关系,以及MRI 0级软骨与退变软骨T2值的差异。 方法 对452例患者以1.5T MR系统行常规膝关节检查后,采用6回波SE序列扫描完成髌骨轴位T2-mapping成像。对髌软骨进行MRI分级,测量并比较髌软骨最厚层面内侧、外侧、全层和病变处的T2值。 结果 MRI 0级髌骨内、外侧软骨和全层软骨的T2值差异无统计学意义(P=0.15)。髌软骨全层T2值与性别无相关性。>60岁者髌软骨T2值高于其他年龄组。当髌软骨退变时,Ⅰ~Ⅳ级T2-病变均明显高于T2-对照(P<0.001),T2-病变也明显高于MR 0级髌软骨的T2值(P<0.001)。Ⅰ~Ⅳ级髌软骨病变的T2值之间差异有统计学意义(P<0.001),且T2值随病变分级升高而增加。 结论 MRI 0级髌软骨全层T2值与性别无相关性,但随年龄增长而增加。髌软骨退变时T2值随病变严重程度而明显增加。MR T2-mapping成像对诊断和监测骨关节早期病变具有很高的临床价值。     

MR多角度屈曲观察髌股关节软骨损伤

目的 通过膝关节多角度屈曲MR扫描,观察膝关节炎髌股关节软骨损伤的位置,判断最容易引起髌股关节软骨损伤的运动角度,探讨膝关节的安全运动方式。方法 对22例骨关节炎患者的膝关节分别在伸直位和被动屈曲0°、10°、20°、30°、40°、50°、60°的状态下进行快速自旋回波质子加权像加脂肪抑制序列（PD-TSE-FS）扫描,矢状位图像上观察髌股关节软骨损伤的位置。结果 髌股关节软骨内T2WI信号异常4处,局限性软骨变薄20处,关节软骨局限性缺损12处。膝关节被动屈曲时,软骨损伤在30°~60°内均有对合情况,对合最多的角度为40°,在<30°屈曲角度扫描中仅发现1例软骨损伤对合的病例。结论 膝关节屈曲30°~60°时髌骨软骨与股骨滑车软骨损伤在对应面出现的频率最高。屈曲<30°时髌骨软骨与股骨滑车软骨损伤在对应面出现的频率较低。     

磁共振T1ρ成像检测兔膝关节软骨早期退变

目的 探讨磁共振T1ρ成像检测兔膝关节软骨早期退变的可行性。方法 将32只实验兔随机分组;其中24只(实验组)随机分为A~D组,每组6只,均予左侧膝关节腔内注射木瓜蛋白酶,建立关节软骨早期退变的模型;余8只作为空白对照组(E组),随机分为E_A、E_B、E_C、E_D亚组,每组2只,分别做为A、B、C、D组的空白对照。于末次注药后1、2、3、4周分别对A~D组(对E_A、E_B、E_C、E_D亚组进行同期对照成像)行双膝常规T2W、3D-FS-SPGR和T1ρ扫描后处死并取双膝关节股骨髁软骨做组织学检查。测量并分析兔股骨髁软骨T1ρ值组内及组间的差异,并与组织学结果对照。结果 实验组处理侧(左侧)股骨髁软骨T1ρ值均明显高于对照侧(P<0.05);实验组处理侧股骨髁软骨T1ρ值随时间推移逐渐升高(P<0.05);T1ρ伪彩图显示实验组处理侧软骨呈浅绿色向深绿色的渐进性改变;组织学检查显示实验组处理侧股骨髁软骨发生早期退变,软骨内PG含量明显下降。结论 T1ρ值能够敏感地量化反映关节软骨退变早期、形态学改变之前的蛋白多糖变化。T1ρ成像可能为临床检测关节软骨早期退变提供影像学依据。     

T2*mapping辅助MRI技术对差异性膝关节骨性关节炎软骨损伤程度的诊断价值

目的探讨T2*mapping辅助MRI技术对差异性膝关节骨性关节炎软骨损伤程度的诊断价值。方法选取我院2016年6月~2019年6月收治的膝关节骨性关节炎患者作为病变组,共46例,其中男性32例,女性14例,年龄22~69岁(41.19±15.53岁);另将7名健康志愿者作为对照组,其中男性5例,女性2例,年龄23~64岁(42.05±15.28岁)。两组均行膝关节MRI常规扫描及T2*mapping序列扫描,分别比较两组不同区域软骨T2*值,分析病变组软骨损伤程度、各区域浅深层软骨以及股骨内侧髁、外侧髁负重区与非负重区的T2*值。结果病变组股骨内侧髁、股骨外侧髁、内侧胫骨平台、外侧胫骨平台T2*值均高于对照组(P < 0.05)。重度患者股骨内侧髁、股骨外侧髁、内侧胫骨平台、外侧胫骨平台T2*值均高于轻度患者(P < 0.05)。病变组股骨内侧髁、股骨外侧髁、内侧胫骨平台、外侧胫骨平台浅层软骨的T2*值均高于深层软骨(P < 0.05)。病变组股骨内侧髁、外侧髁负重区的T2*值均高于负重区(P < 0.05)。结论T2*mapping辅助MRI技术在诊断差异性膝关节骨性关节炎软骨损伤程度中具有较高的价值,可为患者病情的判断提供可靠依据。      

胫骨平台骨折合并膝关节损伤的MRI诊断

目的 评估胫骨平台骨折合并膝关节损伤的MRI影像诊断价值。方法 39例胫骨平台骨折病例经X线平片检查后作MRI扫描,MRI扫描序列包括膝关节矢状位、冠状位及横轴位SE T_1WI,矢状位及冠状位SE T_2WI;比较平台骨折的平片与MRI诊断结果;分析骨折合并膝关节损伤的MRI形态表现。结果 MRI可作出正确的骨折分型诊断,还能显示平片不能诊断的平台隐匿性骨折及骨挫伤;MRI能准确显示骨折合并的膝关节损伤性病变,如关节软骨断裂、半月板损伤、韧带撕裂等。结论 MRI是诊断胫骨平台隐匿性骨折、骨挫伤及骨折合并膝关节损伤的有效影像检查手段。     

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.     

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.     

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.     

Evidence-Based Pain Management and Palliative Care in Issue Four for 2009 of The Cochrane Library

ABSTRACT

The Cochrane Library of Systematic Reviews is published quarterly. Issue 4 for 2009 contains 4027 complete reviews, 1906 protocols for reviews in production, and 11447 one-page summaries of systematic reviews published in the general medical literature. In addition, there are citations of 600,000 randomized controlled trials, and 12,200 cited papers in the Cochrane methodology register. The health technology assessment database contains over 7500 citations. This edition of the Library contains 90 new reviews, of which 19 have potential relevance for practitioners in pain and palliative medicine.     

Wie zuverlässig sind Angaben zu nichtentzündlichen ausgedehnten Schmerzen?

ZusammenfassungFragestellung Es wurde geprüft, wie sich der Differenziertheitsgrad zweier Schmerzmessmethoden auf Angaben zur Ausgedehntheit klinischer Schmerzen auswirkt. Zugleich wurde der Referenzzeitraum variiert, über den die Patienten berichten sollten.Methode Erfasst wurde der Einfluss zu Lasten der Befragungsdifferenziertheit durch den Vergleich zweier Körperschema-Bildvorlagen. Drei Referenzzeiträume (Schmerz aktuell, letzte Woche, letztes halbes Jahr) wurden vorgegeben.Ergebnisse Patienten mit ausgedehnten Schmerzen gaben bei differenzierter Befragung um so mehr Schmerzen an, je weiter die Schmerzen zurück lagen und je größer der Berichtszeitraum war. Patienten mit gelenknahen Schmerzen gaben bei hoch differenzierter Befragung weniger ausgedehnte Schmerzen in der Vergangenheit an als bei globaler Einschätzung. Patienten mit Rückenschmerzen berichteten bei differenzierter Befragung zum aktuellen Schmerz über weniger ausgedehnte Schmerzen als bei globaler Befragung.Schlussfolgerung Die Angaben zur Schmerzausdehnung variieren vor allem bei Patienten mit ausgedehnten Schmerzen in Abhängigkeit von der Differenziertheit der Befragung. In diesen Fällen ist die Wahrscheinlichkeit erhöht, dass sich die Beschwerdesymptomatik zumindest teilweise erst in der Reaktion auf die situativen Befragungsbedingungen konstituiert und daher nicht auf andere Befragungsbedingungen generalisiert werden kann.