中药912液对脓毒症大鼠心肌损伤保护的实验研究

目的观察盲肠结扎穿孔术（CLP）脓毒症模型大鼠心肌损伤的发生情况，以及应用中药912液进行干预的效果及其对心肌的保护作用机制。方法采用CLP制备脓毒症大鼠模型；按照随机数字表法分组。共有56只存活Wistar大鼠进入该实验，其中假手术组8只，CLP模型组24只，中药912液治疗组24只，后两组再分为术后3、24和72h3个时间点亚组。观察各组不同时间点心肌损伤指标[肌钙蛋白T（TnT）、脑钠素（BNP）]，血清炎症因子水平[肿瘤坏死因子-α（TNF-α）、白细胞介素-6（IL-6）、IL-10]和血浆一氧化氮（NO）、丙二醛（MDA）的动态变化。结果CLP模型组大鼠术后3h血浆TnT、TNF-α、IL-6、NO、MDA水平即开始较假手术组明显升高，BNP、IL-10到24h时也明显升高（P〈0．05或P〈0．01）；而中药912液组的TnT、BNP、TNF-α、IL-6、NO、MDA虽较假手术组升高，但明显低于CLP模型组，IL-10则高于CLP模型组（P〈0．05或P〈0．01）。结论脓毒症后可出现明显的心肌损伤，中药912液可通过抑制NO和自由基介导的组织损伤改善脓毒症时的心肌损伤。     

还原型谷胱甘肽对大鼠脓毒症肺损伤外周血淋巴细胞凋亡率及TNF-α、IL-6水平的影响

目的观察还原型谷胱甘肽对大鼠脓毒症肺损伤外周血淋巴细胞凋亡率及血浆细胞因子TNF-α、IL-6水平的影响，探讨还原型谷胱甘肽对大鼠脓毒症肺损伤的保护作用及其机制。方法应用盲肠结扎穿孔（CLP）法复制大鼠脓毒症肺损伤模型。将清洁级雄性SD大鼠112只，随机分成假手术组（Sham）、脓毒症肺损伤组（ALI）、还原型谷胱甘肽治疗组（GSH）、左旋氧氟沙星治疗组（LEV），每组再分为3、6、12、24h等4个亚组，每个亚组n=7。观察大鼠脓毒症肺损伤肺组织的病理形态学改变，并检测外周血淋巴细胞凋亡率及血浆TNF-α、IL-6水平的变化。结果在脓毒症肺损伤组及左旋氧氟沙星治疗组淋巴细胞凋亡率较假手术组及GSH治疗组明显升高（P〈0．05）；在脓毒症肺损伤组血浆TNF-α水平在CLP术后6h出现升高，较GSH治疗组升高明显（P〈0．01）。脓毒症肺损伤组大鼠血浆IL-6水平于CLP术后3h升高，GSH治疗组CLP术后3h血浆IL-6水平较脓毒症肺损伤组低（P〈0．05）。脓毒症肺损伤组大鼠病理显示明显肺损伤，GSH治疗组大鼠肺损伤程度明显减轻。结论还原型谷胱甘肽能显著抑制外周血淋巴细胞凋亡及血浆TNF-α和IL-6表达水平，对大鼠脓毒症急性肺损伤具有明显的保护作用。     

脓毒症大鼠肝脏Toll样受体4水平及还原型谷胱甘肽的干预研究

目的：观察脓毒症大鼠急性肝损伤时肝脏Toll样受体4（TLR4）和肿瘤坏死因子α（TNF-α）水平的变化,探讨还原型谷胱甘肽（GSH）对脓毒症大鼠急性肝损伤的保护作用及其机制。方法：采用盲肠结扎穿孔术（CLP）制备SD大鼠脓毒症肝损伤模型。实验大鼠随机分成假手术组、模型组、GSH干预组（每组各24只）,每组大鼠再按按0h、2h、6h、24h分为4个亚组（每组各6只）。GSH干预组在造模后立即经尾静脉给予GSH（300mg.kg-1）共0.1mL,假手术组和模型组则给予等量0.9%氯化钠溶液。每组大鼠在4个时间点（CLP术后0h、2h、6h、24h）采集血标本和肝组织标本。HE染色观察肝组织病理改变;检测血清肝功能和肝组织TLR4和TNF-α水平的变化。结果：与假手术组相比,模型组大鼠血清肝功能水平在术后6h起开始升高,术后24h仍持续升高;肝组织TLR4和TNF-α水平均在术后2h显著升高,术后6h达到高峰,术后24h有所回落;术后24h肝组织HE染色显示肝细胞肿胀、大量炎性细胞浸润、细胞变性等损伤性改变。与模型组相比,GSH干预组在术后6h和24h血清肝功能损伤指标显著降低（P〈0.05）,而肝组织TLR4和TNF-α水平在术后2h、6h、24h均显著降低（P〈0.05）,肝组织的病理学损伤性改变也明显减轻。结论：在脓毒症早期肝组织TLR4及其调控的炎性因子TNF-α水平增高在脓毒症急性肝损伤中起重要作用;脓毒症早期应用GSH治疗可能通过降低TLR4水平,减少肝组织TNF-α浓度,对脓毒症急性肝损伤有保护作用。     

核因子κB在黄芩苷对脓毒症大鼠肾脏保护中的作用

目的：探讨核因子κB（NF-κB）在黄芩苷对脓毒症大鼠肾脏保护中的作用及其机制。方法：采用盲肠结扎穿孔术（CLP）制备SD大鼠脓毒症模型。实验大鼠随机分成假手术组、模型组、黄芩苷干预组（每组各24只）,每组大鼠再随机分为CLP术后0h、3h、6h、24h4个亚组（每组各6只）。黄芩苷组在造模后立即经腹腔注射黄芩苷120mg/kg,共2mL液体,假手术组和模型组则腹腔注射等量0.9%氯化钠液。每组大鼠在4个时间点（CLP术后0h、3h、6h、24h）采集血标本和肾组织标本。HE染色观察肾组织病理改变;检测血清肌酐水平和用免疫组织化学法测定肾组织肿瘤坏死因子α（TNF-α）、NF-κB在肾组织内的水平。结果：与假手术组相比,模型组大鼠血清肌酐浓度及肾组织TNF-α、NF-κB水平均显著升高（P〈0.05）,术后3h即开始升高并持续至术后24h;术后24h肾组织HE染色显示肾小管区大量炎症细胞浸润。与模型组相比,黄芩苷干预组术后3h、6h和24h血清肌酐浓度及肾组织TNF-α、NF-κB水平均显著降低（P〈0.05）;肾脏组织的炎症病理改变也显著减轻。结论：脓毒症大鼠早期血清肌酐升高与肾组织中TNF-α、NF-κB水平升高有关;脓毒症早期应用黄芩苷治疗对脓毒症大鼠肾脏保护作用的机制可能与降低肾组织NF-κB水平,减轻炎性反应有关。     

黄芩苷对脓毒症大鼠早期肾功能损伤的保护作用

目的：通过观察黄芩苷对脓毒症大鼠血清中性粒细胞明胶酶相关载脂蛋白（NGAL）浓度的影响,探讨黄芩苷对脓毒症大鼠肾功能损伤的早期保护作用。方法：采用盲肠结扎穿孔术（CLP）制备SD大鼠脓毒症模型。实验大鼠随机分成假手术组、模型组、黄芩苷干预组（每纽各24只）,每组大鼠再随机分为0h、3h、6h、24h4个亚组（每组各6只）。黄芩苷组在造模后立即经腹腔给予黄芩苷120mg／kg共2mL液体,假手术组和模型组则给予等量％0．9氯化钠液腹腔注射。每组大鼠在4个时间点（CLP术后0h、3h、6h、24h）采集血标本和肾组织标本。HE染色观察肾组织病理改变;检测血清NGAL和肌酐浓度和用免疫组织化学法测定肾组织肿瘤坏死因子“（TNF-α）水平。结果：与假手术组相比,模型组大鼠血清NGAL和肌酐浓度显著升高（P〈0．05）,术后3h开始升高,术后24h继续升高;肾组织TNF-α水平也显著升高（P〈0．05）,术后3h开始升高,术后24h仍升高;术后24h肾组织HE染色显示肾组织内大量炎症细胞浸润。与模型组相比,黄芩苷干预组术后3h、6h和24h血清NGAL和肌酐浓度以及肾组织TNF-α水平均显著降低（P〈0．05）,肾脏组织的炎症病理改变也明显减轻。结论：黄芩苷对脓毒症大鼠早期肾功能损伤有保护作用。     

脓毒症大鼠血清炎症递质水平的变化

目的：探讨脓毒症大鼠血清炎症递质的变化。方法将30只雄性 SD 大鼠随机分为假手术组10只和脓毒症组20只,采用盲肠结扎穿孔法制作脓毒症模型。采集假手术组造模后颈总动脉血,采集脓毒症组造模后0、24、48、72 h 颈总动脉血,用酶联免疫吸附法检测血清肿瘤坏死因子α（TNF-α）、白细胞介素1（IL-1）、白细胞介素6（IL-6）的浓度。结果假手术组血清 TNF-α为（9.27±3.12）ng/ L,脓毒症组造模后0、24、48、72 h 分别为（9.26±8.01）、（32.01±4.52）、（55.22±7.61）、（83.31±8.57） ng/ L,脓毒症组造模后24、48、72 h 与造模后0 h 和假手术组比较差异均有统计学意义（P 均＜0.01）;假手术组血清 IL-1为（8.93±1.26）ng/ L,脓毒症组造模后0、24、48、72 h 分别为（20.01±3.51）、（25.51±2.79）、（59.67±3.26）、（87.86±11.51）ng/ L,脓毒症组造模后24、48、72 h 与造模后0 h 和假手术组比较差异均有统计学意义（P 均＜0.01）;假手术组血清 IL-6为（12.36±3.25）ng/ L,脓毒症组造模后0、24、48、72 h 分别为（11.52±2.32）、（31.59±12.12）、（57.27±13.53）、（71.59±12.67）ng/ L,脓毒症组造模后24、48、72 h 与造模后0 h 和假手术组比较差异均有统计学意义（P 均＜0.01）。结论脓毒症大鼠血清炎症递质水平明显升高,提示机体过度释放大量炎症递质,可能是导致脓毒症发生的因素之一。     

法舒地尔对敌敌畏中毒大鼠急性肺损伤时血浆肿瘤坏死因子α和白细胞介素-6水平的影响

目的：探讨法舒地尔（Fasudil）对敌敌畏中毒大鼠急性肺损伤时血浆肿瘤坏死因子α（TNF-α）和白细胞介素-6（IL-6）水平的影响。方法：Sprague Dawley大鼠30只,随机分成对照组、敌敌畏（dichlorvos,DDVP）中毒组、法舒地尔干预组3组,每组10只,均予以气管切开接呼吸机辅助通气。6h后留取血样用酶联免疫吸附分析（ELISA）法测血浆TNF-α、IL-6水平。取左肺下叶组织,HE染色观察病理学改变。结果：与对照组比,中毒组和干预组大鼠血浆TNF-α、IL-6水平均显著升高（P〈0.01）,肺组织HE染色有炎症细胞浸润;与中毒组比,干预组TNF-α、IL-6升高程度显著降低（P〈0.05）,肺损伤程度较轻。结论：法舒地尔能降低敌敌畏中毒大鼠血浆TNF-α、IL-6水平,能显著减轻肺损伤的病理损害,对大鼠敌敌畏中毒性急性肺损伤有明显的保护作用。     

持续静脉泵注利多卡因对脓毒症大鼠急性肺损伤及炎症反应的影响

目的探讨利多卡因对脓毒症大鼠肺损伤及炎症因子表达的影响。 方法采用随机数字表法将60只雄性成年Sprague Dawley大鼠分为假手术组、盲肠结扎穿孔（CLP）组、利多卡因组和乌司他丁组,每组各15只。假手术组大鼠打开腹腔后缝合,其他各组采用CLP法制备脓毒症模型。利多卡因组大鼠在给予10 mg/kg的负荷剂量后,以10 mg·kg^-1·h^-1的剂量通过尾静脉持续泵注利多卡因3h;乌司他丁组大鼠进行CLP的同时,以100 000 U·kg^-1·h^-1的剂量通过尾静脉持续泵注乌司他丁3 h;假手术组和CLP组用等量等渗NaCl溶液代替。于CLP后24 h处死大鼠,采用酶联免疫吸附实验（ELISA）法测定血清中肿瘤坏死因子α（TNF-α）、白细胞介素6（IL-6）及高迁移率族蛋白B1（HMGB1）表达水平;实时荧光定量PCR检测肺组织HMGB1 mRNA表达水平;苏木素-伊红（HE）染色法观察各组大鼠肺组织病理变化。另取40只大鼠（每组10只）用于观察4组大鼠72 h死亡情况。 结果4组大鼠血清中TNF-α、IL-6、HMGB1及HMGB1 mRNA表达水平比较,差异均有统计学意义（F = 189.886、237.952、175.999、179.491,P均< 0.001）。进一步两两比较发现,与假手术组比较,CLP组、利多卡因组和乌司他丁组血清TNF-α、IL-6、HMGB1及HMGB1 mRNA表达水平均显著升高（P均< 0.05）;与CLP组比较,利多卡因组和乌司他丁组血清TNF-α、IL-6、HMGB1及HMGB1 mRNA表达水平均显著降低（P均< 0.05）;与利多卡因组比较,乌司他丁组IL-6表达水平显著升高（P < 0.05）。HE染色结果显示,假手术组大鼠肺泡大小均匀、结构完整,肺泡上皮细胞形态正常;CLP组大鼠肺泡间隔增厚、间质充血水肿、炎症细胞浸润、肺泡塌陷;而利多卡因组和乌司他丁组病理学改变较CLP组均明显减轻,肺组织轻度水肿,肺泡及肺间质出现少量炎症。四组大鼠死亡构成比（0 /10、9/1、4/6、3/7）比较,差异有统计学意义（χ²=17.500,P < 0.001）。CLP组、利多卡因组和乌司他丁组大鼠死亡构成比均较假手术组显著升高（P均<0.008）;利多卡因组和乌司他丁组大鼠死亡构成比均较CLP组显著降低（P均<0.008）;而利多卡因组和乌司他丁组大鼠死亡构成比比较,差异无统计学意义（P > 0.008）。 结论持续静脉泵注利多卡因可以有效降低脓毒症大鼠炎症因子TNF-α、IL-6及HMGB1的表达,抑制肺组织中HMGB1 mRNA表达量,减轻脓毒症对肺组织的损伤,有效提高动物存活率,其减轻脓毒症炎症反应及肺保护作用疗效与乌司他丁相似。     

脓毒症大鼠不同时期炎症因子水平与心功能关系的研究

目的探讨脓毒症大鼠炎症因子与心功能之间的关系及其可能机制。 方法采用盲肠结扎穿孔法制备腹腔感染脓毒症动物模型。将120只大鼠分为对照组60只、脓毒症组60只,再按照造模后不同时点分成6个亚组（造模后3、6、12、24、48、72 h）,每个亚组10只大鼠。监测各亚组动物心功能指标左室舒张末压（LVEDP）、左室发展压（LVDP）、左室最大收缩速率（＋dP／dt max）及左室最大舒张速率（＋dp／dt max）,血清炎症因子肿瘤坏死因子α（TNF-α）、白介素6（IL-6）及IL-10,心肌酶谱心肌肌钙蛋白I（cTn I）、肌酸激酶（CK）、肌酸激酶同工酶（CK-MB）。同时电镜下观察心肌超微结构的变化情况。结果与对照组相比较,脓毒症组±dp／dt max、LVDP水平从3 h开始出现下降,至12 h下降最明显（P均〈0．05）,而脓毒症组LVEDP水平于造模后12～48 h与对照组比较均显著升高（P均〈0．05）。脓毒症组TNF—α、IL-6水平于3 h后与对照组比较出现升高（P均〈0．05）,而IL-10在6～72 h后与对照组比较差异均具有统计学意义（P均〈0．05）。同时脓毒症组cTn I、CK、CK．MB水平在不同时间点较对照组均显著增加（P均〈0．05）。此外,电镜观察脓毒症组大鼠心肌超微结构损伤明显至24 h病变最为严重。 结论脓毒症不同时期促炎因子与抗炎因子失衡,可能是导致脓毒症心功能改变的重要因素之-。     

大黄素对脓毒症大鼠保护作用的实验研究

目的探讨大黄素对于脓毒症大鼠的保护作用。方法将健康大鼠随机分为三组,A组：假手术组;B组：盲肠结扎穿刺（CLP）组;C组：CLP大黄素治疗组。造模72h后分别测定各组血浆肿瘤坏死因子-α（TNF-α）、血浆和腹腔白蛋白浓度、肠系膜微静脉流速等并观察肠粘膜损伤程度。结果CLP后大鼠血浆TNF-α浓度、白蛋白渗出率明显升高,而B组升高较C组明显（P〈0.01）,肠粘膜损伤评分变化也有相同趋势（P〈0.017）;肠系膜微静脉流速减慢,血浆白蛋白浓度降低,而B组下降较C组明显（P〈0.05）。结论大黄素能减轻CLP所致脓毒症大鼠的炎症反应和肠粘膜的损伤。     

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.     

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.     

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.     

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.