50 MHz ultrasound characterization of colitis on rats, in vitro

Ultrasound (50 MHz) was used for in vitro characterization of trinitrobenzene sulfonic acid-induced colitis on rats. Images and wave propagation parameters were obtained for colitis (n=38). Mean (plusmn2 se) results are: 1624.90(plusmn20.21) mmiddots^-1 for speed of sound; 5.12(plusmn0.30) dBmiddotmm^-1 for attenuation coefficient; 3.26(plusmn1.03)times10^-3 (srmiddotmm)^-1 for backscattering coefficient and 1.63 (plusmn0.10) for frequency dependence. Integrated backscattering coefficient (IBC), measured across the colon wall (n=4), ranges from 10^-3 to 10^-2 (srmiddotmm)^-1, with the highest IBC values found in the submucosa layer. The result for speed of sound is similar to that of human sclera found in the literature. Results for attenuation and backscattering coefficients are in the same range of literature reports for human sclera and ciliary muscle, respectively. IBC plots allowed for ultrasound scattering quantification of the mucosa, submucosa and muscular layers for TNBS colitis.