Therapeutic Ultrasound for the Heart: State of the Art

This work describes the use of therapeutic ultrasound as a treatment of cardiovascular disease including recent, state of the art approaches. Therapeutic ultrasound researchers have made recent advances in the highly dynamic and changing world of interventional cardiology where they are confronted with several challenges, such as of the complexity of ultrasound propagation in the highly heterogeneous environment of the thorax or the complexity of the heart (in term of motion and physiology). It is believed that with these recent innovations, therapeutic ultrasound for cardiac applications will soon have a place in the toolkit of cardiologists.     

Effects of shear stress on endothelial cells: possible relevance for ultrasound applications

This review forms part of a series of papers resulting from a workshop on safety of ultrasound applications. The physical effects of ultrasound include generation of steady streaming in large fluid volumes, and micro-streaming around contrast bubbles. Such streaming induces shear stress acting on the vascular endothelium. This review provides a discussion on the levels of endothelial shear stress associated with diagnostic ultrasound applications, and on the biological effects of shear stress acting on the endothelial cells. Depending on vessel size and ultrasound characteristics, shear stresses associated with streaming and micro-streaming may exceed the physiological levels associated with the flow of blood by many orders of magnitude. The resulting biological effects could range anywhere from activation of normal shear stress sensors such as ion channels, damage of the endothelial surface layer, reversible perforation of the membrane, to cell detachment and lysis. The possible presence of such biological effects does not necessarily mean that the effects are harmful for the individual. However, considering the ever-increasing use of ultrasound, a further investigation into these shear stress-related effects, using both experiments and modelling, is desired. Apart from safety concerns, such effects may provide a base for strategies aimed at targeted delivery of drugs.     

Therapeutic applications of ultrasound

Therapeutic applications of ultrasound predate its use in imaging. A range of biological effects can be induced by ultrasound, depending on the exposure levels used. At low levels, beneficial, reversible cellular effects may be produced, whereas at high intensities instantaneous cell death is sought. Therapy ultrasound can therefore be broadly divided into “low power” and “high power” applications. The “low power” group includes physiotherapy, fracture repair, sonophoresis, sonoporation and gene therapy, whereas the most common use of “high power” ultrasound in medicine is probably now high intensity focused ultrasound. Therapeutic effect through the intensity spectrum is obtained by both thermal and non-thermal interaction mechanisms. At low intensities, acoustic streaming is likely to be significant, but at higher levels, heating and acoustic cavitation will predominate. While useful therapeutic effects are now being demonstrated clinically, the mechanisms by which they occur are often not well understood.     

超声分子成像的研究进展

超声成像无创、无放射性、低成本、实时成像的优点,使其成为目前世界上应用最广的成像手段之一。特别是超声造影剂引入之后,超声成像的图像分辨率和灵敏度得到了大大提高,使超声成像在临床上得到了进一步应用。近年来,随着分子生物学和超声成像技术的不断发展,人们提出了"超声分子成像"的概念。它是一项结合了分子靶向造影剂和超声影像技术的能在分子水平下观察病理变化的新兴技术,目前这一技术还处于研究初期阶段。但大量临床前的研究成果已表明超声分子成像在诊断血管生成、炎症和血栓三种疾病具有很大应用前景。本文主要综述了目前常用超声造影剂的种类以及超声分子成像技术的研究现状,并对该技术进行了讨论和展望。     

超声分子成像的研究进展

超声成像无创、无放射性、低成本、实时成像的优点,使其成为目前世界上应用最广的成像手段之一。特别是超声造影剂引入之后,超声成像的图像分辨率和灵敏度得到了大大提高,使超声成像在临床上得到了进一步应用。近年来,随着分子生物学和超声成像技术的不断发展,人们提出了＂超声分子成像＂的概念。它是一项结合了分子靶向造影剂和超声影像技术的能在分子水平下观察病理变化的新兴技术,目前这一技术还处于研究初期阶段。但大量临床前的研究成果已表明超声分子成像在诊断血管生成、炎症和血栓三种疾病具有很大应用前景。本文主要综述了目前常用超声造影剂的种类以及超声分子成像技术的研究现状,并对该技术进行了讨论和展望。     

Ultrasound-assisted digestion: a useful alternative in sample preparation

Ultrasound-assisted digestion is a promising alternative in the analysis of solid samples when either simple dissolution or direct analysis is not applicable. However, the field of application of ultrasonic sample digestion is still small in comparison with classical digestion alternatives and, particularly, with microwave-assisted digestion. This fact can be justified by the scant knowledge analytical chemists have about the advantages ultrasonic energy provides to digestion. Among these, the strict control at low temperatures of ultrasound applications allows the implementation of ultrasonic-assisted steps in biochemical analyses. In this connection, two specific biological applications, ultrasonic enzymatic digestion and assistance of ultrasound for cell disruption, are also reviewed.     

Enhanced ROS production and cell death through combined photo- and sono-activation of conventional photosensitising drugs

A combination of light and ultrasound activation of two conventional photosensitising drugs, methylene blue and rose bengal, was shown to generate higher levels of reactive oxygen species (ROS) and lower LD50 values than either light or ultrasound activation alone.     

Sea-trial verification of ultrasonic antifouling control

An ultrasonic antifouling treatment was applied to a 96,000 m³ class drill-ship to verify its feasibility through a sea-trial. Soon after the hull cleaning had been performed, six ultrasonic projectors were evenly deployed around the starboard shell plate. Driven by a 23 kHz sinusoidal ultrasound in an intermittent manner, the projectors emitted a high-intensity sound reaching 214 dB at the source level causing cavitation around the adjacent water and eventually deterring the settlement of marine fouling organisms. Underwater photographs acquired after four months showed fairly clean slabs on the starboard side, but heavy fouling on the port side. This experiment revealed that ultrasound treatment is a promising method for inhibiting fouling accumulation, even for large-scale ship applications.     

超声介入治疗常见妇科囊性炎症包块的疗效评价

目的：比较超声引导介入治疗盆腔脓肿、输卵管积脓、输卵管积液、包裹性积液及宫颈囊肿的,临床效果,了解超声引导介入治疗常见的妇科囊性炎症包块的临床价值。方法：选取我院妇科门诊2007年1月～2011年3月收治的常见妇科囊性炎症包块共108例,其中盆腔脓肿11例、输卵管积脓19例、输卵管积液43例、盆腔包裹性积液31例、宫颈囊肿4例,给予超声实时引导抽囊液、甲硝唑冲洗治疗,治疗后3个月内复查超声评价和比较疗效。结果：盆腔脓肿、输卵管积脓、盆腔包裹性积液包块均明显缩小（12／43）或消失（29／43）,治疗有效率100％;输卵管积液包块治疗有效率95％（41／43）,宫颈囊肿均痊愈。各组间比较无统计学差异（P〉O．05）。结论：超声引导介入治疗对输卵管积脓、盆腔脓肿、盆腔包裹性积液均有显著的疗效,且治疗效果无差异,值得推广应用,代替传统的非必要的手术治疗。     

超声在甲状腺良恶性结节鉴别诊断中的应用进展

超声技术一直是临床诊断的重要方法之一,特别是针对甲状腺疾病,超声检查被认为是鉴别甲状腺结节良恶性的首选方法。但常规超声检查为临床诊断提供辅助的同时也具有一定的局限性。随着影像学的发展,三维超声成像、超声造影及超声弹性成像等超声新技术逐渐应用于甲状腺结节良恶性的鉴别诊断中,并且发挥了重要的作用。本文对甲状腺结节的常规超声检查及超声新技术检查的临床应用进行综述,为甲状腺结节的良恶性鉴别诊断提供科学依据。     

超声波在生物工程中的应用

研究发现在酶和细胞催化的生物反应过程中,较低强度的超声作用可提高酶的催化活性或加速细胞的代谢过程。本文主要简述超声波作用的物理机制并对其在生物工程中的应用前景进行讨论。     

基于超声的多模式功能化对比剂研究进展

超声对比剂的使用使得超声诊断更加准确,扩大了超声成像的应用范围。但单一影像技术难以满足肿瘤等重大疾病临床诊断和治疗的需求。因此开发以超声对比剂为核心,具有多模式成像功能,或同时兼备肿瘤诊断和治疗功能的多模式功能化对比剂是目前的一大研究热点。多模式成像的结合可以实现优势互补,诊断和治疗功能的结合为使得肿瘤等重大疾病的解决提供了新理念和新希望,具有重要意义。本文就基于超声的多模式功能化对比剂进行综述。     

膀胱子宫内膜异位症的超声诊断(附三例临床分析及文献复习)

本文通过3例经活检和手术证实的膀胱子宫内膜异位症的超声图像分析,讨论了膀恍子宫内膜异位症的超声诊断价值。 半数以上的膀胱子宫内膜异位症有盆腔手术史。临床表现为月经期伴尿频尿急和尿痛等尿道刺激的症状,抗炎治疗常难奏效,而月经净后症状自行缓解和消退。 超声图见子宫峡部的前壁外缘有不规则的隆起,呈低回声区并向膀胱后壁突起。在月经来潮前和来潮时此隆起包块稍见增大饱满。用丹那唑或三苯氧胺治疗病灶将逐渐缩小。本文比较了膀胱镜检查的优越性及其局限性,认为超声检查可作为首选的检查方法进行早期诊断,尤其对需采取保守治疗的患者,超声检查可作定期随访以观疗效,而不需反复进行膀胱镜检。超声检查此症应与膀胱血管瘤,膀胱癌,息肉和炎症溃疡等鉴别。     

超声对胃蛋白酶，胰蛋白酶，过氧化氢酶作用的研究

以胃蛋白酶,胰蛋白酶,过氧化氢酶溶液在超声处理下的酶活变化为指标研究超声对蛋白质作用的机理和影响因素。结果表明超声对蛋白质的破坏程度随着功率的升高或处理时间的延长而增加;三种酶在超声作用下酶活变化形式和程度各不同;浓度是影响超声对酶作用效果的一个重要因素,可通过调整酶溶液浓度来减少酶所受到的破坏程度。自由基清除剂甘露醇和非离子表面活性剂吐温-80可以对酶活在超声作用下起到一定的保护作用,说明自由基和超声空穴是超声破坏酶结构的重要机理,研究结果同时表明对于不同的酶,超声的破坏作用可能有不同的发挥主导作用机理。     

正常胎盘的超声图像定量分析研究

我们用ＤＦＹ－Ｉ型超声图像定量分析诊断仪,测定组织结构超声图像的分贝,灰阶值,本文检测分析了３９例正常台盘测值。     

超声造影和超声弹性成像在甲状腺良恶性结节鉴别诊断中的临床价值

目的:探讨超声造影与超声弹性成像鉴别诊断甲状腺良恶性结节的临床价值。方法:回顾性分析2011年1月-2013年6月我院经病理证实的128例甲状腺占位性病变患者(160个结节)的超声影像学资料,其中恶性结节68个,良性占位92个,评估实时超声造影与超声弹性成像诊断甲状腺良性与恶性结节的敏感性、特异性、准确率、阳性预测值及阴性预测值。结果:甲状腺良性结节超声造影检查以快进慢出、高增强为主;恶性结节以慢进快出、低增强为主。超声造影诊断甲状腺良、恶性结节的灵敏度、特异度与阳性预测值、阴性预测值及其诊断符合率分别为91.18%、92.39%、91.18%、93.41%、91.88%;超声弹性成像分别为89.71%、90.22%、87.14%、92.22%、90.00%,联合检查分别为94.12%、95.65%、94.12%、95.65%、95.00%,均高于常规超声的57.35%、72.83%、60.94%、69.79%、65.63%,比较差异有统计学意义(P0.05);联合检查灵敏度、符合率明显高于超声造影与超声弹性成像单一检查,比较差异有统计学意义(P0.05)。结论:超声造影与超声弹性成像在鉴别诊断甲状腺良恶性结节中均具有较高的应用价值,两种方法联合检查灵敏度及准确性更高。     

眼部常见疾病的超声诊断分析

目的：总结眼部常见疾病的超声表现,探讨超声对其的诊断价值。方法：对2009年6月～2010年6月来我院超声科行眼部超声检查（占位性病变经手术或病理学结果证实）的63例患者的资料进行回顾性分析,归纳总结了眼部常见疾病的二维超声（2D）、彩色多普勒（CDFI）及超声造影（CEUS）表现。结果：眼部疾病的超声图像在位置、形状、边界、声学特点及对周围组织的影响等方面具有特征性表现;超声造影能有效地显示出病灶内的血管及血流灌注情况。结论：超声对眼部常见病的诊断是一种简便、无创、经济且诊断符合率高的辅助影像学方法,具有较高的实际应用价值。     

Intensification of biokinetics of enzymes using ultrasound-assisted methods: a critical review

The use of low intensity ultrasound has gotten surprising consideration over the last decade as a method for enhancing the catalytic activity of enzyme. Ultrasounds have the potential to significantly influence the activity of the enzymatic processes, provided that the energy input is not so high as to inactivate the enzyme. By providing the variation in parameters, various physical and chemical effects can be attained that can enhance the enzymatic reaction. Ultrasonic reactors are known for their application in bioprocesses. However, the potential of their applications is still limited broadly due to the lack of proper information about their operational and performance parameters. In this review, the detailed information about ultrasonic reactors is provided by defining the different types of reactors and number and position of ultrasonic transducers. Also, it includes mechanism of intensification and influence of ultrasonic parameters (intensity, duty cycle, and frequency) and enzymatic factors (enzyme concentration, temperature, and pH) on the catalytic activity of enzyme during ultrasound treatment.     

The use of 2D ultrasound elastography for measuring tendon motion and strain

The goal of the current study was to investigate the fidelity of a 2D ultrasound elastography method for the measurement of tendon motion and strain. Ultrasound phantoms and ex vivo porcine flexor tendons were cyclically stretched to 4% strain while cine ultrasound radiofrequency (RF) data and video data were simultaneously collected. 2D ultrasound elastography was used to estimate tissue motion and strain from RF data, and surface tissue motion and strain were separately estimated using digital image correlation (DIC). There were strong correlations (R²>0.97) between DIC and RF measurements of phantom displacement and strain, and good agreement in estimates of peak phantom strain (DIC: 3.5±0.2%; RF: 3.7±0.1%). For tendon, elastographic estimates of displacement profiles also correlated well with DIC measurements (R²>0.92), and exhibited similar estimated peak tendon strain (DIC: 2.6±1.4%; RF: 2.2±1.3%). Elastographic tracking with B-Mode images tended to under-predict peak strain for both the phantom and tendon. This study demonstrates the capacity to use quantitative elastographic techniques to measure tendon displacement and strain within an ultrasound image window. The approach may be extendible to in vivo use on humans, which would allow for the non-invasive analysis of tendon deformation in both normal and pathological states.