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Biomedical subjects

F L Thurstone

Publications and source records attributed to F L Thurstone.

10 recordsLinked to original sources

Principles and applications of a dynamically focused phased array real time ultrasound system.

The physical principles and clinical applications of a high-resolution, dynamically focused phased-array real time ultrasound are described. Advantages of the real time technique include rapid survey capability, efficient selection of an appropriate tomographic plane, identification of pulsating structures, and dynamic studies. The capabilities of a high resolution phased array with extended dynamic focusing to a range of 15-20 cm are demonstrated in vascular, abdominal, and obstetric imaging. Appropriate clinical examples showing normal and pathological anatomy are presented. Comparisons with conventional B scans are illustrated.

Abdomen

Dynamic cardiac imaging using a focused, phased-array ultrasound system.

A two-dimensional ultrasound imaging system capable of producing high resolution, cross-sectional images of the heart in real-time has been developed. This system relies upon phased-array principles to rapidly steer and focus the ultrasound beam through the cardiac structures under investigation. A hand-held, linear array of 24 transducers is manipulated on the anterior chest wall to image various cardiac structures. Images of high line density are presented in selectable sector arcs to a maximum of 90 degrees. This imaging system has proved particularly useful for the detection of a variety of left ventricular and cardiac valvular disease.

Computers

Cardiac imaging using a phased array ultrasound system. I. System design.

A new two-dimensional, real-time, high resolution ultrasound imaging system is described. This system uses a linear array of ultrasound transducers to generate tomographic images of the heart in a circular sector format. Phased array techniques allow rapid steering of the ultrasound beam so that images are produced at the rate of 20 per second, or more, while maintaining a resolution of 2-4 mm throughout the field of view.

Echocardiography

Cardiac imaging using a phased array ultrasound system. II. Clinical technique and application.

A new two-dimensional ultrasound imaging system capable of producing high resolution tomographic images of the heart in real time has been developed. This system relies on phased array principles to rapidly steer the ultrasound beam through the structures under investigation. A hand-held linear array of 16 ultrasound transducers with overall dimensions of 14 mm at the site of contanct may be readily manipulated to image various cardiac structures. The resulting images are displayed in a circular sector format, 60 degrees in azimuth and typically 15 cm in range. At his maximum range, image frames consisting of 256 lines are generated at the rate of 20 frames/second. High azimuthal resolution throughout the field of view is assured by a focused transmit beam and by sweeping the focus of the receiver is synchrony with the range of returning echoes. Azimuthal resolution varies from 2 to 5 mm throughout the field of view while range resolution is 1.5 mm. This imaging system has proven particularly useful for the delineation of left ventricular spatial geometry by the identification of endocardium, myocardium, papillary muscles and interventricular septum. High quality images of anterior and posterior mitral leaflets, aortic root and aortic leaflets as well as left atrium and other cardiac structures have been obtained.

Echocardiography

Real time ultrasound tomography of the adult brain.

Initial clinical results are reported from a new real time, 2-dimensional ultrasound scanner modified for adult cephalic applications. An optimized transducer design and the use of the dynamically focused phased array imaging system have resulted in ultrasound tomograms of the brain which are significant improvements over previous attempts. Horizontal and coronal images of the ventricles, the corpus callosum and other midline structures are routinely displayed in a 45 degrees sector format. In addition, pulsating cerebral arteries are displayed in real time. Quantitative information can be obtained concerning cerebral vascular patency by using the selectable M-mode feature of this system. The results indicate that real time ultrasound tomography has potential for clinical application.

Adult

Clinical results of real-time ultrasonic scanning of the heart using a phased array system.

This report describes the operating characteristics and initial clinical results of a new echocardiographic system that produces real-time, high resolution, cross-sectional images of the heart. This system relies upon phased-array principles to rapidly steer and focus the ultrasound beam through the cardiac structures under investigation. A hand-held, linear array of 24 transducers is manipulated on the patient's chest to direct the interrogating plane at various cardiac structures. Images of high line density are presented in selectable sector arcs to a maximum of 90 degrees. This imaging system has been used clinically in over 2,000 patients in the past two and one-half years. Its use in the detection of altered states of ventricular and valvular pathology has been described.

Computers