00068467

00068467 - IEEE TRANSACTIONS ON ULTRASONICS,...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
109 IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL, VOL 38. NO 2. MARCH 1991 High-speed Ultrasound Volumetric Imaging System- Part 11: Parallel Processing and Image Display Olaf T. von Ramm, Stephen W. Smith, and Henry G. Pavy, Jr. Abstract-A real-time volumetric ultrasound imaging system has been developed for medical diagnosis. The scanner produces images analo- gous to an optical camera or the human eye and supplies more infor- mation than conventional sonograms. Potential medical applications include improved anatomic visualization, tumor localization and better assessment of cardiac function. The system uses pulse-echo phased ar- ray principles to steer a 2-D array transducer of 289 elements in a pyramidal scan format. Parallel processing in the receive mode pro- duces 4992 scan lines at a rate of approximately 8 frames /s. Echo data for the scanned volume is presented on-line as projection images with depth perspective, stereoscopic pairs, or multiple tomographic images. I. INTRODUCTION NEW ultrasound imaging system has been developed that A uses a hand-held transducer, capable of rapidly scanning a volume and enabling the three-dimensional ( 3-D ) visualization of dynamic structures in real time. We will describe the design considerations and preliminary evaluation of this high-speed, on-line volumetric ultrasound imaging system that uses the principles of pulse-echo, phased array scanning with a two-di- mensional (2-D) array transducer. In Part I, [l] we discussed the principles of phased array beam steering in two dimensions to obtain a volumetric scan. We also described the design, fab- rication and evaluation of two dimensional array transducers for volumetric scanning. The most significant challenge to the development of the high- speed volumetric ultrasound imaging system is the limited data acquisition rate of pulse-echo ultrasound scanning. For typical depths of 15 cm in tissue for cardiac or abdominal scanning, the propagation velocity of ultrasound waves in tissue, i.e., = 1540 m/s, limits pulse-echo ultrasound to a pulse repetition frequency of = 5000 transmit pulses/s in order to avoid redun- dant echoes from overlapping pulses. In conventional high speed ultrasound cross-sectional imaging, the 5000 transmit pulses are typically allocated to fewer than 160 scan lines per B-mode im- age at a rate of 30 frames s. A high speed v?olumetric pulse- echo scan that utilizes a similar field of view in both elevation and azimuth would require that approximately 160 B-scans be obtained in the time of a single conventional sonogram, i.e., an increase in data acquisition rate by a factor of 160. One solution to this problem is thk technique of parallel re- ceive mode processing. In this method, multiple image scan Manuscript received April 4, 1990; revised August 6, 1990; accepted August 7, 1990. This work was supported in part by HHS Grant #37586 and in part by NSFIERC #CDR-8622201.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 7

00068467 - IEEE TRANSACTIONS ON ULTRASONICS,...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online