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。     

Anisotropic growth shapes intestinal tissues during embryogenesis

Embryogenesis offers a real laboratory for pattern formation, buckling, and postbuckling induced by growth of soft tissues. Each part of our body is structured in multiple adjacent layers: the skin, the brain, and the interior of organs. Each layer has a complex biological composition presenting different elasticity. Generated during fetal life, these layers will experience growth and remodeling in the early postfertilization stages. Here, we focus on a herringbone pattern occurring in fetal intestinal tissues. Common to many mammalians, this instability is a precursor of the villi, finger-like projections into the lumen. For avians (chicks’ and turkeys’ embryos), it has been shown that, a few days after fertilization, the mucosal epithelium of the duodenum is smooth, and then folds emerge, which present 2 d later a pronounced zigzag instability. Many debates and biological studies are devoted to this specific morphology, which regulates the cell renewal in the intestine. After reviewing experimental results about duodenum morphogenesis, we show that a model based on simplified hypothesis for the growth of the mesenchyme can explain buckling and postbuckling instabilities. Being completely analytical, it is based on biaxial compressive stresses due to differential growth between layers and it predicts quantitatively the morphological changes. The growth anisotropy increasing with time, the competition between folds and zigzags, is proved to occur as a secondary instability. The model is compared with available experimental data on chick’s duodenum and can be applied to other intestinal tissues, the zigzag being a common and spectacular microstructural pattern of intestine embryogenesis.     

FibroScan临床应用新进展

近10年来,应用瞬时弹性扫描仪(FibroScan)作为肝纤维化的无创检测方法已得到广泛共识.为了更有效地利用该技术,设备制造者在原有基础上进行了软件升级及硬件扩展.虽然观察时间尚短,但已有文献表明改进后的技术可能适用范围更广.除肝纤维化检测外,研究还发现FibroScan检测结果与患者的疾病进展和生存情况相关.作为一项技术手段,诸多因素会影响其操作成功率和检查准确率,了解这些因素有利于降低检测失败率,提高检测效能.     

实时超声弹性成像技术在宫颈癌的应用研究

目的 探讨助力式及声力式弹性成像技术在宫颈癌诊断的应用价值.方法 应用助力式弹性成像技术(ETE)及声触诊组织量化技术(VTQ)检测44例宫颈癌患者病灶及50例正常宫颈,记录图像及测量相关数值进行分析统计.结果 ETE诊断宫颈癌的敏感度88.6％,特异度94％;宫颈癌VTQ均值(2.68±0.49) m/s,明显大于正常宫颈VTQ均值(1.53±0.47) m/s (P＜0.05).结论 ETE及VTQ检查均显示宫颈癌病变的硬度明显增加,且随着宫颈癌分期越高硬度越硬,说明弹性超声成像技术在协助宫颈癌的诊断上有应用价值.     

Diagnosing cysts with correlation coefficient images from 2-dimensional freehand elastography.

OBJECTIVE: We compared the diagnostic potential of using correlation coefficient images versus elastograms from 2-dimensional (2D) freehand elastography to characterize breast cysts. METHODS: In this preliminary study, which was approved by the Institutional Review Board and compliant with the Health Insurance Portability and Accountability Act, we imaged 4 consecutive human subjects (4 cysts, 1 biopsy-verified benign breast parenchyma) with freehand 2D elastography. Data were processed offline with conventional 2D phase-sensitive speckle-tracking algorithms. The correlation coefficient in the cyst and surrounding tissue was calculated, and appearances of the cysts in the correlation coefficient images and elastograms were compared. RESULTS: The correlation coefficient in the cysts was considerably lower (14%-37%) than in the surrounding tissue because of the lack of sufficient speckle in the cysts, as well as the prominence of random noise, reverberations, and clutter, which decorrelated quickly. Thus, the cysts were visible in all correlation coefficient images. In contrast, the elastograms associated with these cysts each had different elastographic patterns. The solid mass in this study did not have the same high decorrelation rate as the cysts, having a correlation coefficient only 2.1% lower than that of surrounding tissue. CONCLUSIONS: Correlation coefficient images may produce a more direct, reliable, and consistent method for characterizing cysts than elastograms.     

综合性医院手术科室分配机制技术框架探讨

卫生系统的改革依赖于包括分配机制在内的适宜的内部管理运行机制的催化。作者在分析综合性医院政策限度和技术限度基础上，构想手术科室分配机制的技术框架。引入“综合系数”、“人时”单位、“收入弹性系数”等概念，建立定量考核指标体系，确定指标的期望值以及各类手术之间的换算比例。分配机制紧紧依托卫生系统现有的宏观环境，机制的诱导趋势与卫生政策的导向一致。由于最重要的指标－－期望月均手术量的核定是建立在现有人员构成基础上，故可以避免按床位定编将产生的人员分流组合所带来的振荡，为医院重新调配资源创造灵活的空间，同时可确保各科相互之间的比较具有水平公平性。     

Biophysical characteristics of skin in diabetes: a controlled study

Background  Cutaneous complications are common in diabetes. Previous assays suggest that hyperglycemia and decreased insulin signal are involved in the impairment of skin function. The aim of this study was to evaluate the biophysical characteristics of skin in patients with diabetes mellitus and compares them with healthy non-diabetic controls.
Objective  To measure biophysical characteristic of skin including transepidermal water loss (TEWL), water content, sebum and skin elasticity in patients with diabetes mellitus and compare them with healthy non-diabetic controls.
Methods  This case-control study was conducted on 38 patients with diabetes and 40 age- and sex-matched healthy people. The biophysical properties of skin including stratum corneum (SC) hydration, sebum content, TEWL and skin elasticity were measured and compared between the two groups at three different locations of the body.
Results  The measurement of SC hydration and TEWL showed no significant difference between diabetics and controls. The skin surface lipids on the forehead but not other sites were significantly lower in the diabetics than in the controls. Acoustic wave propagation speed, a measurement related to skin elasticity, was significantly lower in forearm and forehead of diabetics.
Conclusion  Diabetes affects some functional properties of epidermis and dermis that may responsible for many cutaneous manifestations of diabetes. These results suggest that patients with diabetes mellitus tend to show a normal hydration state of the SC together with decreased sebaceous gland activity and impaired skin elasticity, without any impairment of the SC barrier function.

Conflicts of interest

None declared     

Microscopic magnetic resonance elastography (microMRE).

Magnetic resonance elastography (MRE) was extended to the microscopic scale to image low-frequency acoustic shear waves (typically less than 1 kHz) in soft gels and soft biological tissues with high spatial resolution (34 micromx34 micromx500 microm). Microscopic MRE (microMRE) was applied to agarose gel phantoms, frog oocytes, and tissue-engineered adipogenic and osteogenic constructs. Analysis of the low-amplitude shear wave pattern in the samples allowed the material stiffness and viscous loss properties (complex shear stiffness) to be identified with high spatial resolution. microMRE experiments were conducted at 11.74 T in a 56-mm vertical bore magnet with a 10 mm diameterx75 mm length cylindrical space available for the elastography imaging system. The acoustic signals were generated at 550-585 Hz using a piezoelectric transducer and high capacitive loading amplifier. Shear wave motion was applied in synchrony with the MR pulse sequence. The field of view (FOV) ranged from 4 to 14 mm for a typical slice thickness of 0.5 mm. Increasing the agarose gel concentration resulted in an increase in shear elasticity and shear viscosity. Shear wave motion propagated through the frog oocyte nucleus, enabling the measurement of its shear stiffness, and in vitro shear wave images displayed contrast between adipogenic and osteogenic tissue-engineered constructs. Further development of microMRE should enable its use in characterizing stiffer materials (e.g., polymers, composites, articular cartilage) and assessing with high resolution the mechanical properties of developing tissues.