The automated waterpath scanner (Octoson)--advantages and limitations in diseases of the liver, pancreas and gallbladder.

In a comparative study of 591 examinations the Octoson and a conventional ultrasound scanner were analysed. Examinations with the Octoson showed a sensitivity of 92% and with a conventional ultrasound scanner a sensitivity of 82% in diseases of the liver. With the long focus of the Octoson's large aperture transducers, it is possible to demonstrate both superficial and deep subdiaphragmatic metastases. It is difficult, however, to find the optimal scanning angle with this system, and for this reason examinations undertaken in disorders of the gallbladder and bile ducts require considerably more time. In pancreatic disease (Octoson sensitivity: 77%; conventional ultrasound scanner sensitivity: 65.35%) the favourable air distribution in the stomach and transverse colon is advantageous when the examination is performed with the patient in the prone position.