豚鼠耳蜗毛细胞暴露非聚焦超声后的酶组织化学观察

目的　探讨非聚焦超声 (non focusedultrasound ,NFU)对耳蜗毛细胞的影响。方法　以A型超声波诊断仪为超声发射器 ,分别以 2 5MHz、8MHz照射各 15耳豚鼠耳蜗 6h后 30min和 8h行耳蜗基底膜毛细胞铺片及冰冻切片观察琥珀酸脱氢酶 (succinatedehydrogenase ,SDH)组织化学变化。结果　 2 5MHz、8MHzNFU照射豚鼠耳蜗 6h后 8h能引起不同节段基底膜毛细胞SDH酶活性降低 ,其中外毛细胞较内毛细胞SDH酶活性降低更甚。照射后 8h组较照射后 30min组SDH酶活性有明显恢复。结论不同频率NFU超声照射耳蜗达一定剂量可以引起不同部位基底膜毛细胞的病理性缺氧改变 ,而这种缺氧病理改变在一定暴露剂量下是可逆或部分可逆的。提示耳蜗毛细胞可能与超声感受有关 ,其中外毛细胞可能起更为重要的作用 ,且不同部位毛细胞与超声感受的频率选择性可能有一定关系     

彩色多普勒监测脐血流预测胎儿宫内状况

运用彩色多普勒监测正常妊娠、好高征、合并ＩＵＧＲ的ｖ妊高征胎儿脐动脉血流，计测血流的Ｓ／Ｄ值、ＰＩ值、ＲＩ值。结果表明，妊高征（合并或不合并ＩＵＧＲ）胎儿脐动脉血流阻力指标明显大于正常妊娠组，经治疗后，妊高征胎儿脐动脉血流阻力指标降低者，临床表现好转，反之恶化。阻力指标异常升高，预示胎儿宫内状况差、胎儿窘迫或发生ＩＵＧＲ，有助于及时发现异常和处理，降低围产儿死亡率。     

Determination of acoustic power outputs in the microwatt-milliwatt range

A system using an electrobalance for radiation pressure measurements has been developed capable of determining acoustic powers in the microwatt-milliwatt range. Low background “noise” levels are achieved by effective isolation of the balance from building vibrations and shielding the target from convection currents. The standard deviation for a power output of 1 mW is typically less than 1 percent.     

Choice of standard target for medical pulse-echo equipment evaluation

Comparisons have been made between plane, spherical and cylindrical targets in relation to their suitability for quantitative evaluation of the performance of pulse-echo equipment for visualizing tissues. Using fifteen different transducers, with various frequencies and beam-shapes, spherical targets were found to relate much more closely (scatter of 12 dB) than did plane targets (40 dB) with the target strength measured in post mortem human liver.     

定量骨超声对诊断甲状腺功能亢进症患者骨代谢异常的意义

目的探讨定量骨超声在甲状腺功能亢进症(甲亢)骨代谢异常中的意义。方法选择118例甲亢患者,用Sunlight-Ominisense超声骨强度仪检测其桡骨、胫骨超声波传导速度(SOS),双能X线骨密度仪测定其腰椎、股骨近端骨密度。用放射免疫方法测定血清总甲状腺素(TT4),总三碘甲状腺原氨酸(TT3),游离甲状腺素(FT4),游离三碘甲状腺原氨酸(FT3)和促甲状腺激素(TSH)的水平。血生化的方法测定血碱性磷酸酶。结果与正常对照比较,甲亢患者胫骨和桡骨SOS降低(40~50岁:3809±171vs.3955±102,3881±713vs.4187±114;50~60岁:3721±223vs.3852±102,3875±201vs.4035±114),差异均有统计学意义(均P<0·05);SOS与骨密度呈显著性正相关(P<0·05);甲亢胫骨和桡骨SOS异常的发生率(Z值≥-1的发生率分别为41·2%、43·3%,-2·5相似文献   

Acoustic properties of normal and cancerous human liver—I. Dependence on pathological condition

Ultrasonic speed, attenuation and backscattering were measured as functions of frequency and orientation in specimens of exercised human liver, with a view to establishing the usefulness of such measurements to characterize the pathology and structure of the tissue. It is observed that acoustic speed is superior to any attenuation or backscattering characteristics for distinguishing in vitro between specimens of tumours and normal human liver selected at random. However, when the data are corrected for variations between one subject and another, sound speed, attenuation and the mean back-scattering coefficient at a given frequency show a comparable degree of usefulness in this respect. Analysis of the periodicities present in the backscattering diffraction patterns did not contribute any improvement in the ability to distinguish between tissue states. On average, by comparison with normal liver, ultrasound travels about 1.5% (± 1%) slower, is attenuated by about 20% (± 30%) less at 3 MHz and is backscattered by about 80% (±115%) less at 3 MHz in the tumor specimens that were measured. Livers infiltrated by diffuse malignant disease appear to possess quite different ultrasonic propagation properties to normal liver although insufficient data are yet available for firm conclusions to be drawn.     

Zur Treffsicherheit der Gallenblasensonographie

Zusammenfassung Es wird über eine Serie von 158 durch Operation kontrollierten Sonographiebefunden der Gallenblase berichtet. Die Treffsicherheit der Gallensteindiagnostik betrug 99,3 % bei einem falsch-positiven, aber keinem falsch-negativen Ergebnis. Die Sonographie ist eine wenig zeitaufwendige, den Patienten nicht belastende und billige Untersuchungsmethode für die Abklärung von Gallenblasenerkrankungen. Sie sollte daher — möglichst mit einem Real-time-Gerät — als erstes apparativ-diagnostisches Verfahren eingesetzt werden.

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Accuracy of ultrasonics in gallbladder diseases

Summary Report on 158 ultrasonic findings of gallbladder diseases, all of them controlled by laparotomy. The diagnostic accuracy for stones was 99.3% with one false-positive but without any false-negative result. Because ultrasonics is a less time consuming and inexpensive method without trouble for patients, it should be used — if possible with a real-time equipment — as the first apparatively-diagnostic procedure in cases of suspected gallbladder diseases.

     

Blood cell banding in ultrasonic standing wave fields: A physical analysis

Blood cell flow can be arrested in living tissue by exposing the blood vessels to ultrasound in a stationary wave field. The cells form into bands at half wavelength intervals in the blood vessels. This phenomenon is described, and the forces that may be involved are discussed. The forces considered include standing wave radiation pressure, inter-cellular forces and Oseen forces. A computer model is described and the computed trajectories of cells under the action of these forces are shown.