Quantitative ultrasound backscatter parameters in the human cervix

Quantitative ultrasound has been investigated as a tool for monitoring cervical changes that might result in preterm birth. Backscatter parameters, specifically attenuation and the backscattered power loss (BSPL), appear to be two important parameters. Sources of potential variability such as the angle of the beam interrogating the cervix, the region within the cervix, the number of previous births, and the state of ripening, have not been systematically examined, but could contribute to bias and variance in parameter estimates. Results presented here show that attenuation was affected by angle of interrogation, region in the cervix, parity, and ripened state. BSPL in the nonpregnant cervix was affected only by cervical region.