Ultrasonic diffraction scanning of the thyroid

This paper reports the results of a preliminary clinical assessment of the value of ultrasonic diffraction analysis in identifying thyroid pathology. The trial involved 52 patients and nine normal volunteers and showed that, when used as a supplement to grey-scale B-scanning, diffraction analysis is capable of useful separation among several categories of pathology.     

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.

     

Two-dimensional diffraction scanning of normal and cancerous human hepatic tissue in vitro

A technique and associated equipment are described which investigate the acoustic signals backscattered from small tissue volumes and interrogated over a solid angle of transmitter/receiver positions. This two-dimensional diffraction technique produces acoustic scatter maps termed, by us “interferograms”, which are analysed to determine their usefulness in discriminating between normal, freshly excised liver tissue and cancerous tissue within the intact organ. The “interferograms” are collected at three different narrow-band frequencies and have been used in investigating 26 normal liver and 13 liver tumour samples. The preliminary results indicate that this novel technique has a 97% success in discriminating normal liver from tumour, compared to an 87% success achieved by two observers when scoring conventional sector B-scan images of the same tissue regions.     

Structural and functional changes in the cochlea following ultrasonic irradiation

Following ultrasonic irradiation of the cochlea cellular damage was observed within the hair cells of the organ of Corti and in the stria vascularis. The outer hair cells were more susceptible to damage than the inner hair cells. These immediate morphological changes did not occur when the intracochlear temperature was raised in the absence of ultrasound. Functional changes were determined from measurements of the cochlear microphonic response and the endolymphatic potential during ultrasonic irradiation. Cochlear irradiation produced a permanent depression in the positive E.P. In addition a depression in the microphonic response occured which comprised two distinct phases the slower of which was reversible. The permanent depression resulted from the combined effect of ultrasonic and thermal energy. The reversible change may be due to restriction in the energy available to the organ of Corti resulting from the influence of ultrasound on the stria vascularis.     

Doppler ultrasound in orifice flow. In vitro studies of the relationship between pressure difference and fluid velocity

The validity of an orifice equation (Torricelli's law) which expresses a simple relationship between the pressure difference across an orifice and the maximum fluid velocity in the orifice was tested in vitro. An aqueous suspension of barium sulfate particles with a polymer added to attain variations in viscosity, was forced through orifices which ranged in diameter from 0.4 to 4.7 mm. The pressure difference across the orifice was determined with a transducer and the maximum fluid velocity in the orifice was determined with Doppler ultrasound. Tests were performed at Reynolds numbers, fluid viscosities, and pressure differences that spanned the following ranges: 400-25,000, 1-5 cP, and 3-100 mmHg, respectively. At pressure differences larger than 3 mmHg and fluid viscosity 3 cP (approximate viscosity of in vivo blood), Torricelli's law was demonstrated to be valid for orifice diameters larger than 1.6 mm. The validity of the law was found to be relatively insensitive to variations in orifice length.     

先天性冠状动脉瘘—5例报告

本文报告5例先天性冠状动脉瘘。4 例术前进行了主动脉造影配合X线电影检查。2 例有二维超声检查结果。4例手术证实,1 例升主动脉造影证实。本文着重分析有关X线诊断问题。     

A partial uterine perforation (type 2) by a copper-T IUD: sonographic diagnosis and management

The case reported in this paper demonstrates the difficulties in establishing the diagnosis of type 2 uterine perforation incident to the use of an IUD. A type 2 perforation is considered to have occurred when the IUD is entirely within the myometrium, no part of the IUD can be detected in the uterine cavity, and no part can be visually detected in the peritoneal cavity. The patient, a 28-year old gravida 3, para 2, had an IUD inserted 18 months prior to admittance, 7 weeks after her 2nd delivery. 1 year later she became pregnant. During a therapeutic abortion, the IUD string was removed without the device, which was considered to be outside and behind the uterus. Ultrasonography revealed that the IUD was inside the posterior uterine wall, parallel to the endometrial mucosal lining, with no connection to the uterine cavity. Other diagnostic methods used in this case included plain abdominal films, hysterography, and hysteroscopy; however, neither these methods nor uterine palpation suggested that there was an IUD in the uterus. The original diagnosis was later confirmed by intraoperative radiography, and the IUD was removed through a small incision on the posterior uterine wall. This case demonstrates the useful role of ultrasonography in the work-up of a woman with a missing IUD. It is suggested that ultrasonography be used following difficult IUD insertions or postpartum insertions, since most perforations occur in such cases. Partial and complete uterine perforation is considered more likely when the IUD is inserted during the 1st 3 months postpartum.     

The directional characteristics of some ultrasonic doppler blood-flow probes

A knowledge of the shape of the fields generated by Doppler ultrasonic probes is of particular importance in vessel imaging and in blood flow research. In this study the combined effects of the transmitting and receiving crystals of four types of commonly used Doppler probe have been calculated numerically using two different theoretical models, and the results compared with experimental measurements. The results show that there is a considerable variation in the fields produced by transducers of the same type, and that the correspondence between the theoretical and experimental results can be improved in most cases by using a model in which each crystal vibrates like a flexible plate rather than like a rigid piston. Theoretical iso-echo contours at various distances from the transducer face are presented for each of the four types of transducers studied.