Quantitative ultrasound diagnosis of endometrial cysts.

We measured the ultrasonic frequency dependent attenuation of ovarian cysts using the spectral difference method to find the difference in the characteristics of attenuation of the endometrial cyst and other ovarian cysts. We investigated an analytical method to measure the ultrasonic frequency dependent attenuation of ovarian cysts and we called this method the boundary echo spectrum method. The endometrial cyst had an attenuation slope of 0.67 +/- 0.27 dB/cm/MHz, and attenuation value was 1.85 +/- 1.27 dB/cm, and it had significantly higher attenuation slope and attenuation value compared with those of serous cystadenoma and mucinous cystadenoma, but no significant difference compared with those of dermoid cyst (fat component). Compared with attenuation slope and attenuation value, attenuation slope is superior because of smaller standard deviation and better linearity between water immersion and transabdominal method.