Ultrasound in medicine & biology
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The first ocular echogram was published in 1956. Since then, ophthalmic ultrasound has developed into a multifaceted diagnostic discipline, the basic methods being A-scan and B-scan, Doppler techniques and recently also three-dimensional approaches. Unique for ophthalmology is the newly invented, highly resolving equipment utilising ultrasound frequencies of 50 MHz and higher, so-called ultrasound biomicroscopy. ⋯ As for orbital pathology, imaging by CT and MR appears more complete. Ultrasound is valuable, however, in particular as part of the initial clinical work-up, and for the follow-up of orbital disease. Furthermore, tissue differentiation by way of ultrasound is of great value with regard to certain entities.
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Ultrasound Med Biol · Jan 1997
Comparative StudyLower frequency (5 MHZ) intracardiac echocardiography in a large swine model: imaging views and research applications.
Our previous investigation indicated that, in the 50-114-kg weight range, the swine model provides transeosophageal echocardiographic normal values for cardiac structures comparable to those found in human adults. Intracardiac echocardiographic imaging using a 12.5-MHz ultrasound catheter is limited, due to ultrasonic attenuation. Transesophageal echocardiographic imaging of the right heart is also limited with its anterior anatomic location. ⋯ Major intracardiac anatomic landmarks (i.e., crista terminalis, right atrial appendage, coronary sinus orifice, interatrial septum, tricuspid valve, right ventricular outflow, pulmonary veins, mitral valve and left ventricular papillary muscles) were visualized in every swine. Thus, this 5-MHz multiplane transducer, as a prototype for a steerable low-frequency intracardiac ultrasound catheter, improved both whole heart and individual cardiac structure imaging from a single intracardiac location. Further technological development and refinement is needed for routine use in research and clinical imaging practice.
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Ultrasound Med Biol · Jan 1997
Comparative StudyInsufficient and absent acoustic temporal bone window: potential and limitations of transcranial contrast-enhanced color-coded sonography and contrast-enhanced power-based sonography.
The aim of this study was to investigate the diagnostic potential of contrast-enhanced transcranial color-coded sonography (CE-TCCS) and contrast-enhanced transcranial power-based sonography (CE-TPS) in patients with insufficient or absent acoustic bone windows (IABW). Due to temporal bone thickness, the basal cerebral circulation could not be insonated in 21 of 172 patients using unenhanced transcranial color-coded real-time sonography (TCCS) and transcranial power-based sonography. Additional CE-TCCS and CE-TPS were performed after application of 400 mg/ml galactose microbubble suspension. ⋯ In conclusion, CE-TCCS and CE-TPS appear to be sensitive ultrasonic tools that provide reliable data regarding the basal cerebral circulation in patients with IABW. Furthermore, CE-TPS offers advantages over CE-TSSC in the identification of small-caliber arteries and vessels that run at unfavorable angels to the ultrasound beam. Both methods can overcome hyperostosis of the skull that is a major hindrance in transcranial ultrasonography, and may be helpful in the diagnosis of occlusive diseases of intracranial vessels.