Title :
Improved in vivo abdominal image quality using real-time estimation and correction of wavefront arrival time errors
Author :
Rigby, E.W. ; Chalek, C.L. ; Haider, B.H. ; Lewandowski, R.S. ; O´Donnell, M. ; Smith, L.S. ; Wildes, D.G.
Author_Institution :
Corp. Res. & Dev., Gen. Electr. Co., Schenectady, NY, USA
Abstract :
The speed of sound varies with tissue type, yet commercial ultrasound imagers assume it is constant. Sound speed variation in abdominal fat and muscle layers is widely believed to be largely responsible for poor image contrast and resolution in some patients. The simplest model of the abdominal wall assumes that it adds a spatially varying time delay to the ultrasound wavefront. We describe an adaptive imaging system consisting of a GE LOGIQ 700 imager connected to a multi-processor computer. Arrival time errors for each beamforming channel, estimated by correlating each channel signal with the beamsum signal, are used to correct the imager´s transmit and receive beamforming time delays at the image frame rate. A multi-row transducer provides two dimensional sampling of wavefront arrival time errors. After beamforming time delay correction, we observe significant improvement in abdominal images of healthy male volunteers, including increased contrast of blood vessels, increased brightness of liver tissue, and improved definition of the renal capsule and splenic boundary
Keywords :
acoustic signal processing; adaptive signal processing; biological organs; biological tissues; biomedical transducers; biomedical ultrasonics; blood vessels; brightness; image resolution; image sampling; kidney; liver; medical image processing; real-time systems; ultrasonic transducer arrays; GE LOGIQ 700 imager; abdominal fat; abdominal wall; adaptive imaging system; arrival time errors; beamforming channel; beamsum signal; blood vessels; brightness; channel signal; healthy male volunteers; image contrast; image frame rate; improved definition; improved in vivo abdominal image quality; liver tissue; multi-processor computer; multi-row transducer; muscle layers; real-time estimation; receive beamforming time delays; renal capsule; resolution; sound speed variation; spatially varying time delay; speed of sound; splenic boundary; tissue type; transmit beamforming time delays; two dimensional sampling; ultrasound wavefront; wavefront arrival time error correction; wavefront arrival time errors; Abdomen; Array signal processing; Computer errors; Delay effects; Image quality; Image resolution; In vivo; Muscles; Spatial resolution; Ultrasonic imaging;
Conference_Titel :
Ultrasonics Symposium, 2000 IEEE
Conference_Location :
San Juan
Print_ISBN :
0-7803-6365-5
DOI :
10.1109/ULTSYM.2000.921639