阈值提取法用于压缩感知3D mDIXON肝脏脂肪定量的可行性

目的 探讨肝脏阈值提取法用于压缩感知3D mDIXON肝脏脂肪定量的可行性。方法 对28名健康志愿者以加速因子2行肝脏压缩感知3D mDIXON序列扫描。由2名影像科医师分别采用阈值提取法和传统轴位ROI法测量全肝脂肪含量，并记录2种方法测量脂肪分数的时间；分析2种方法定量肝脏脂肪分数的可重复性及2种方法测量结果的相关性。结果 2名医师采用阈值法获得的脂肪分数分别为（3.53±1.34）%及（3.40±1.24）%，一致性较好（ICC=0.996，P=0.001）；采用传统轴位ROI法测量的脂肪分数分别为（2.35±1.35）%及（2.31±1.13）%，一致性亦较好（ICC=0.994，P=0.001）。阈值提取法[（3.47±1.29）%]和轴位ROI法[（2.45±1.30）%]获得的肝脏脂肪分数呈高度正相关（r=0.997，P=0.001）。阈值提取法平均测量时间（3.2±0.8）min，轴位ROI法平均测量时间（5.0±0.3）min。结论 阈值提取法可方便快捷地用于压缩感知3D mDIXON肝脏脂肪定量。     

基于敏感性编码及压缩感知技术优化颅脑MR三维相位对比静脉造影成像序列

目的 对比以不同加速因子（acceleration factors，AF）敏感性编码（SENSE）与压缩感知（CS）及SENSE组合（CS-SENSE）技术所获颅脑三维相位对比MR静脉造影（3D PC-MRV）图像质量，以优化序列。方法 前瞻性对26名健康志愿者以AF分别为6和9的SENSE技术，以及AF分别为9、12、15及18的CS-SENSE技术采集颅脑3D PC-MRV，并依次记为MRV_SENSE6、MRV_SENSE9、MRV_CS9、MRV_CS12、MRV_CS15和MRV_CS18。比较上矢状窦（SSS）和左（L）、右（R）侧乙状窦（SiS）在各组3D PC-MRV软组织图中，以及SSS和左（L）、右（R）侧横窦（TRS）的信噪比（SNR）和对比度噪声比（CNR）在各组3D PC-MRV幅度图中的差异；对比整体图像质量及静脉窦和脑静脉结构可视化主观评分。结果 3D PC-MRV软组织图中，除CNR_R-SiS外，MRV_SENSE6的SNR_SSS、CNR_SSS、SNR_R-SiS及SNR_L-SiS均高于MRV_SENSE9（P均<0.05），MRV_CS9、MRV_CS12及MRV_CS15图像各参数均高于MRV_SENSE9（P均<0.05）而与MRV_SENSE6差异均无统计学意义（P均>0.05），MRV_CS18的SNR_R-SiS和SNR_L-SiS均低于MRV_SENSE6，CNR_L-SiS高于MRV_SENSE9，SNR_SSS、SNR_R-SiS及SNR_L-SiS低于MRV_CS9及MRV_CS12，SNR_R-SiS低于MRV_CS15（P均<0.05），其余参数差异均无统计学意义（P均>0.05）；3D PC-MRV幅度图中，MRV_SENSE6各参数均高于MRV_SENSE9，MRV_CS9及MRV_CS12均高于MRV_SENSE6，MRV_CS9、MRV_CS12、MRV_CS15及MRV_CS18均高于MRV_SENSE9，MRV_CS15及MRV_CS18均低于MRV_CS9，MRV_CS18低于MRV_CS12（P均<0.05），其余各参数差异均无统计学意义（P均>0.05）；对图像质量的主观评分结果与上述客观评价结果相似。结论 相比SENSE，基于CS-SENSE的3D PC-MRV可在更短时间内获得质量更优的颅脑静脉图像；AF取12为优化序列。     

对比PETRA-MRA、TOF-MRA及CTA评估颅脑前循环动脉狭窄

目的 对比径向采集逐点编码缩短时间MR血管成像（PETRA-MRA）、时间飞跃法MRA （TOF-MRA）及CT血管成像（CTA）评估颅脑前循环动脉狭窄程度及长度的效能。方法 回顾性分析56例经颅脑数字减影血管造影（DSA）确诊颅脑前循环动脉狭窄患者的颅脑PETRA-MRA、TOF-MRA和CTA资料,采用组内相关系数（ICC）及Bland-Altman法观察PETRA-MRA与TOF-MRA、CTA评估颅脑前循环动脉狭窄程度及长度与DSA结果的一致性,以及分析上述评估结果与DSA的相关性。结果 Bland-Altman分析显示,以DSA为标准,PETRA-MRA评估颅脑前循环动脉狭窄程度的变异系数、偏差及一致性限度范围分别为13.30%、1.04及（－13.37,15.46）,TOF-MRA分别为15.89%、2.81及（－14.68,20.29）,CTA分别为20.17%、11.19及（－12.66,35.04）。PETRA-MRA、TOF-MRA及CTA评估颅脑前循环动脉狭窄程度（ICC=0.92、0.89、0.80）,以及PETRA-MRA、TOF-MRA评估颅脑前循环动脉狭窄长度与DSA结果的一致性均好（ICC=0.99、0.97）,而CTA评估颅脑前循环动脉狭窄长度与DSA结果的一致性差（ICC=0.30）。PETRA-MRA、TOF-MRA及CTA评估颅脑前循环动脉狭窄程度（r_s=0.94、0.86、0.80）及其长度（r_s=0.98、0.97、0.70）均与DSA结果呈正相关（P均<0.01）。结论 PETRA-MRA评估颅脑前循环动脉狭窄的效能优于TOF-MRA及CTA。     

声触诊弹性成像技术量化评估孕晚期妊娠糖尿病患者胎盘弹性

目的 评价声触诊弹性成像(STE)技术量化评估孕晚期妊娠糖尿病(GDM)患者胎盘弹性的价值。方法 前瞻性纳入51例确诊的孕晚期GDM患者,由2名医师分别以STE技术测量胎盘母体面及胎儿面弹性模量,其中1名医师测量2次;以组内相关系数(ICC)及Bland-Altman图评价观察者内及观察者间测量结果的一致性,比较胎盘母体面及胎儿面平均弹性模量(E_mean)差异。结果 观察者内及观察者间测量GDM患者胎盘母体面及胎儿面弹性模量的一致性均好(观察者内:ICC=0.908、0.887;观察者间:ICC=0.827~0.905)。Bland-Altman图示STE量化评估胎盘弹性的一致性良好。胎盘母体面及胎儿面的中位E_mean分别为6.01(5.62,6.51) kPa及5.02(4.46,5.52) kPa,差异有统计学意义(P＜0.001)。结论 STE可稳定地量化评估孕晚期GDM患者胎盘弹性;胎盘母体面及胎儿面弹性存在差异。     

不同压缩感知加速因子对头部3D-T1WI成像质量及基于体素的形态测量定量参数的影响

目的 观察不同压缩感知（CS）加速因子对头部3D-T1WI及基于体素的形态测量（VBM）定量参数的影响,筛选CS最佳加速因子。方法 对25名成人健康志愿者分别以敏感性编码（SENSE）技术（相位加速因子为3）和不同加速因子（4、6、8、10） CS技术采集头部3D-T1WI,测量3D-T1WI_SENSE3、3D-T1WI_CS4、3D-T1WI_CS6、3D-T1WI_CS8及3D-T1WI_CS10中的双侧尾状核灰质及胼胝体膝、压部和颅脑顶部白质信号强度（SI）及标准差（SD）,计算图像信噪比（SNR）和对比噪声比（CNR）,对图像质量进行主观评分;并行VBM,获得全脑体积（TIV）、灰质体积（GMV）、白质体积（WMV）及脑脊液体积（CSFV）,比较各3D-T1WI的SNR、CNR、主观评分及VBM定量参数的差异。结果 不同3D-T1WI的SNR、CNR及主观评分差异均有统计学意义（P均<0.05）;两两比较,3D-T1WI_CS6与3D-T1WI_SENSE3的SNR、CNR,3D-T1WI_CS4及3D-T1WI_CS6与3D-T1WI_SENSE3主观评分差异均无统计学意义（P均>0.05）,其余图像的SNR、CNR及主观评分差异均有统计学意义（P均<0.05）。基于各3D-T1WI的VBM定量参数TIV、GMV、WMV及CSFV差异均无统计学意义（P均>0.05）。结论 以CS技术采集头部3D-T1WI可在保证成像质量且不影响VBM结果的前提下缩短扫描时间;CS6为最佳加速因子。     

基于压缩感知技术三维MRI用于半月板损伤

目的 探讨压缩感知（CS）技术三维MRI（3D-MRI）用于膝关节成像的可行性及其评估半月板损伤的价值。方法 对26例疑诊膝关节损伤患者（损伤组）及30名健康志愿者（对照组）行膝关节MRI，采集常规脂肪抑制质子加权图像（fsPDWI）和CS-3D-MRI。记录损伤组患者关节镜检查结果。损伤组患者于关节镜检查前接受MRI，以单一DS方式（CS-DS_medium）重建图像，分析CS-3D-MRI诊断结果与关节镜结果的一致性。对照组均行右膝扫描，以3种降噪（DS）水平（CS-DS_weak、CS-DS_medium、CS-DS_strong）重建CS-3D-MRI，采用主、客观方法评价矢状位图像质量。结果 对照组不同方法重建CS图像和fsPDWI图像质量评分差异无统计学意义（Z=0.35，P=0.32）；4个序列图像信噪比（SNR）和对比信噪比（CNR）差异均有统计学意义（F=36.01、9.62，P均<0.05），CS-DS_strong图像SNR最高（P<0.05），fsPDWI与CS-DS_medium图像之间CNR值差异无统计学意义（P>0.05）。损伤组CS-3D-MRI均显示半月板损伤，与关节镜诊断结果的一致性强（Kappa=0.94，P<0.01）。结论 基于CS技术的3D-MRI可用于膝关节成像，能在保证图像质量的前提下缩短扫描时间，评估膝关节半月板损伤有较高价值。     

三种经胸肺部超声检查技术诊断间质性肺疾病的可重复性及一致性

目的 探讨3种经胸肺部超声检查（TLUS）技术诊断间质性肺疾病（ILD）的可重复性及一致性。方法 由2名超声科医师对40例ILD患者分别采用简化的14肋间隙扫查法、28肋间隙扫查法、72肋间隙扫查法行TLUS，对比同一医师及不同医师采用不同技术检测结果的可重复性、一致性及扫查时间。结果 同一医师和不同医师利用3种超声技术对B线评价的可重复性及一致性均较高，其中同一医师利用14肋间隙扫查法的可重复性[ICC=0.989 1，95%CI（0.977 2，0.994 8）]及一致性最高[界限宽度0.57±2.79，95%CI（-0.47，1.61）]，不同医师利用14肋间隙扫查法的可重复性[ICC=0.9795，95%CI（0.9575，0.9902）]及一致性最高[界限宽度0.70±3.77，95%CI（-0.71，2.11）]。同一医师、不同医师利用14肋间隙扫查法观察胸膜线严重程度的一致性高（Kappa值=0.948、0.895，P均<0.001）。3种超声技术扫查时间差异有统计学意义（P<0.001），其中14肋间隙扫查法时间最短，72肋间隙扫查法最长。结论 3种TLUS技术中，14肋间隙扫查法的可重复性及一致性最高，且用时最短。     

同时多层分段读出平面回波弥散加权成像

目的 评价同时多层（SMS）分段读出平面回波（RS-EP）弥散加权成像（DWI）用于乳腺的可行性及全肿瘤直方纹理分析参数鉴别乳腺良、恶性肿瘤的价值。方法 纳入185例经病理证实的女性乳腺肿瘤患者,均为单发病灶,根据肿瘤性质分为良性组（n=58）及恶性组（n=127）;采集SMS RS-EP DWI图像,提取全肿瘤直方图参数及纹理参数,采用组内相关系数（ICC）评价观察者内及观察者间的可重复性,并对比组间各参数差异。绘制受试者工作特征（ROC）曲线,计算曲线下面积（AUC）评价定量参数鉴别乳腺良、恶性肿瘤的效能。结果 观察者内及观察者间ADC_Kurtosis、观察者间ADC_Entropy一致性中等（ICC均 ≤ 0.75）,其余参数均一致性较好或极好（ICC均>0.75）。除ADC_SD和ADC_Kurtosis外,其他参数组间差异均有统计学意义（P均<0.05）。直方图参数中,ADC_Median鉴别乳腺良、恶性肿瘤的AUC最高（0.879）;纹理参数中,ADC_Entropy的AUC值最高（0.764）;二者联合诊断的AUC为0.911,敏感度和特异度分别为90.55%和81.03%。结论 SMS RS-EP DWI可用于乳腺检查;联合全肿瘤直方纹理分析有助于鉴别乳腺良、恶性肿瘤。     

定量CT测定人体腹部脂肪分布、肝脏脂肪含量与肥胖的相关性

目的 探讨人体腹部脂肪分布、肝脏脂肪含量与肥胖的相关性。方法 收集于我院接受定量CT （QCT）腰椎骨密度（BMD）检查的健康体检者123名,将受检者分为肥胖组与正常组,比较2组间L_2~3、L_3~4、L_4~5、L₅~S₁椎间隙水平层面的腹腔内脏脂肪面积（VAA）、肝脏脂肪含量百分比β值,分析肥胖组与正常组差异有统计学意义的椎间隙水平层面VAA值与年龄、BMI的相关性。结果 肥胖组L_4~5椎间隙水平层面VAA较正常组增大（P=0.005）,2组余椎间隙VAA比较差异无统计学意义（P均 > 0.05）;肥胖组肝脏脂肪含量百分比β值较正常组增高（P=0.001）;肥胖组L_4~5椎间隙水平层面VAA与年龄及BMI均呈正相关（r=0.485、0.389;P=0.012、0.049）。结论 QCT可评估肥胖者腹部脂肪的分布;L_4~5椎间隙水平层面VAA可预测肥胖风险;肝脏脂肪含量百分比β值在定量诊断肥胖者肝脏脂肪含量具有特异性。     

4D flow心脏MRI测量左心室血流动力学参数的可靠性

目的 观察基于心脏MRI（CMRI）以局部区域性4D flow及全心4D flow技术测量左心室血流动力学参数的可靠性。方法 前瞻性对31名健康体健者采用心脏超声、三腔心4D flow（基于左心室流入流出道层面）及全心4D flow CMRI测量左心室血流动力学参数,以组内相关系数（ICC）评估其所测左心室血流动力学参数的一致性。结果 心脏超声与三腔心4D flow CMRI所测收缩期主动脉瓣上/瓣下峰值流速、舒张期二尖瓣E峰流速、主动脉瓣上/瓣下压力及主动脉瓣跨瓣压差的一致性均良好（ICC均>0.75）,所测舒张期二尖瓣A峰流速的一致性中等（ICC为0.718）;心脏超声与全心4D flow CMRI所测收缩期主动脉瓣上/瓣下峰值流速、舒张期二尖瓣A峰流速及主动脉瓣上/瓣下压力的一致性均良好（ICC均>0.75）,所测舒张期二尖瓣E峰流速及主动脉瓣跨瓣压差的一致性均为中等（ICC分别为0.600及0.628）;三腔心4D flow CMRI与全心4D flow CMRI测量上述指标结果的一致性均良好（ICC均>0.75）。结论 基于CMRI以局部区域性4D flow与全心4D flow技术测量左心室血流动力学参数可靠,与心脏超声测量结果具有良好一致性。     

Guns and Knives in New Mexico: Patterns of Penetrating Trauma, 1978–1993

Objective: To identify patterns of nonfatal and fatal penetrating trauma among children and adults in New Mexico using ED and medical examiner data.
Methods: The authors retrospectively sampled in 5-year intervals all victims of penetrating trauma who presented to either the state Level-1 trauma center or the state medical examiner from a 16-year period (1978–1993). Rates of nonfatal and fatal firearm and stabbing injury were compared for children and adults.
Results: Rates of nonfatal injury were similar (firearm, 34.3 per 100,000 person-years; stabbing, 35.1). However, rates of fatal injury were significantly different (firearm, 21.9; stabbing, 2.7; relative risk: 8.2; 95% confidence interval: 5.4, 12.5). From 1978 to 1993, nonfatal injury rates increased for children (p = 0.0043) and adults (p < 0.0001), while fatal penetrating injury remained constant. The increase in nonfatal injury in children resulted from increased firearm injury rates. In adults, both stabbing and firearm nonfatal injury rates increased.
Conclusions: Nonfatal injury data suggest that nonfatal violence has increased; fatal injury data suggest that violent death rates have remained constant. Injury patterns vary by age, mechanism of trauma, and data source. These results suggest that ED and medical examiner data differ and that both are needed to guide injury prevention programs.     

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.     

Systematic Reviews Published in the January 2011 Issue of The Cochrane Library

ABSTRACT

The Cochrane Library of Systematic Reviews is published quarterly as a DVD and monthly online. The January 2011 issue (first quarterly DVD for 2011) contains 4515 complete reviews, 1985 protocols for reviews in production, and 13,521 one-page summaries of systematic reviews published in the general medical literature. In addition, there are citations of 641,000 randomized controlled trials, and 14,018 cited papers in the Cochrane methodology register. The health technology assessment database contains over 9300 citations. One hundred and seven new reviews have been published in the last 3 months, of which five have potential relevance for practitioners in pain and palliative medicine.     

Interprofessional approaches to creating safe,high quality health care

Three supplementary perspectives are presented arguing that interprofessional collaboration is both necessary and desirable. Nonetheless, there are often too many serious intra-professional barriers and obstacles to interprofessional collaboration to make it successful. Some of these barriers, it is argued and illustrated, are found in the multiple ways in which professional identity is tacitly acquired and embodied in the practitioners' habitual, everyday practice. The paper then explores ways in which reflection, especially Second order reflection, can help to elucidate and overcome these obstacles, as well as increasing professional adaptability and competence.     

Modified micro-superior percutaneously-assisted total hip: early experiences & case reports

Because of the extensile nature and familiarity of the standard posterior-lateral approach to the hip, a family of "micro-posterior" approaches has been developed. This family includes the Percutaneously-Assisted Total Hip (PATH) approach, the Supercapsular (SuperCap) approach and a newer hybrid approach, the Supercapsular Percutaneously-Assisted Total Hip (SuperPATH) approach. Such approaches should ideally provide a continuum for the surgeon: from a "micro" (external rotator sparing) posterior approach, to a "mini" (external rotator sacrificing) posterior approach, to a standard posterior approach. This could keep a surgeon within his comfort zone during the learning curve of the procedure, while leaving options for complicated reconstructions for the more practiced micro-posterior surgeons. This paper details one author's experiences utilizing this combined approach, as well as permutations of this entire micro-posterior family of approaches as applied to more complex hip reconstructions.     

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.     

Prise en charge des entorses externes de cheville : étude clinique préliminaire sur l’efficacité du dispositif Myolux™

Ankle sprains are the most common injury of the musculoskeletal system and are associated with significant societal and economic impacts. It has been proven that classical therapeutic strategies may not be effective in preventing recurrent injuries: the recurrence rates reported in the literature can reach 73%. In order to provide an effective rehabilitation solution, a destabilizing orthosis was developed. This device is equipped with a mechanical articulator reproducing the subtalar mechanics and placed under the heel. In this paper, we present the main results of a preliminary clinical study conducted between 2004 and 2007. All subjects included in this study were treated with the abovementioned orthosis during 10 rehabilitation sessions of 30 minutes each. Data show a relatively low recurrence rate of 12% for the overall population. Moreover, it's of primary importance to note that this satisfactory ratio is largely reduced (3% of recurrence rate) for the 29 patients who performed one training session per month after the 10th initial rehabilitation sessions. Hence, the destabilizing orthosis appears to be an effective solution to prevent recurrent ankle sprains. However, joint protection requires long-term and regular training sessions. This result has motivated the development of a similar device allowing patients to perform training sessions at home. Finally, data obtained in this study are promising awaiting the final results of the comparative, multicentric and independent clinical trials currently managed by the Hospices Civils de Lyon.