[Interference factors in sonography of the middle and lower abdomen]

Disturbing factors in diagnostic ultrasound of the mid-abdomen und lower abdomen are presented. Factors causing unsatisfactory sonographic studies were analysed in 304 sonographic studies of the middle abdomen and lower abdomen. The retroperitoneal space was not demonstrated in 31 of 304 cases (10.2%). Plain films of the abdomen and computed tomography demonstrated fat in subcutaneous tissue, the omentum and the mesenterium in 20 of 31 cases (66%) and intestinal gas in 11 of 31 cases (36%). If ultrasonic studies demonstrate diffuse accumulation of echos, then repetition of the study is not recommended, since computed tomography will provide more reliable results.