Mann W
Arch Otorhinolaryngol. 1975 Nov 30;211(2):145-7. doi: 10.1007/BF01221122.
Echography, combined with routine X-rays of the paranasal sinuses, has been used in more than 300 patients. The diagnosis was controlled by clinical examination, endoscopy and operation. The combination of the two techniques reduces the diagnostic error in paranasal sinus disease to 5%.