MEASUREMENTS OF ULTRASONIC BACKSCATTER COEFFICIENTS IN HUMAN LIVER AND KIDNEY IN-VIVO

Ultrasonic backscatter coefficients, in the range of 2.0-4.0 MHz, were measured in normal human livers and kidneys in vivo. In liver, data w ere acquired and analyzed from 15 normal volunteers and 19 patients wi th hepatitis. No significant difference. between normal and chronic he patitis was found. The power-law fit to the backscatter coefficient in normal Liver as a function of frequency was eta(f)=4.5X10(-5) f(1.6) cm(-1) Str(-1). This is comparable to that measured by other investiga tors in in vitro preparations of human and animal liver and to that me asured by two other teams of investigators in in vivo human liver. In kidney, data were acquired from 11 normal volunteers. The power-law fi t to the backscatter coefficient in normal kidney was eta(f)=2.3 X 10( -5) f(2.1) cm(-1) Str(-1) This is in the range of that measured by oth er investigators in in vitro preparations of human and animal kidney. Ln order to assess the system dependence of in vivo abdominal organ ba ckscatter coefficients, measurements were performed using two differen t ultrasonic data-acquisition systems. The two systems exhibited close agreement. (C) 1995 Acoustical Society of America.