Wertigkeit der Konventionellen Sonographie zur Diagnostik einer Choledocholithiasis im Vergleich zur Endoskopisch Retrograden Cholangiographie

The aim of this study was to assess the diagnostic accuracy ot transabdominal ultrasound in patients with suspected choledocholithiasis. 150 consecutive patients with suspecteded biliary tree obstruction were evaluated prospectively with ultrasonography (with endoscopic retrograde cholangiography as gold-standard). The sensitivity of ultrasonography was 78,6% and the specificity 90,9% (p<0,001). The diagnostic accuracy depended on the bile duct diameter: the sensitivity reached 95,2% (p<0,001) for a diameter of more than 13mm. The presence of dilatation of the Ductus hepatocholedochus (sensitivity: 84,5%; specificity: 42,4%) also correlated significantly with the presence of choledocholithiasis (p<0,001). Obstructive tumors, as an important differential diagnosis of bile duct stones, were shown by ultrasonography with a sensitivity of 88,2% and spezificity of 93,1% (p<0.001). Liver function tests (n.s.) and clinical parameters such as colic (sensitivity 65,4%, specificity 68,3% (p=0,004)) and fever (n.s.) showed a lower diagnostic accuracy in the detection of common bile duct stones. Conclusion: Ultrasound has a high diagnostic accuracy as compared with direct cholangiography in the detection of bile duct stones. It remains the first line investigation for the assessement of choledocholithiasis because of it`s noninvasivity, it`s wider availability and lower costs. Magnetic resonance cholangiography and endoscopic ultrasonography provide useful diagnostic information, but the indication of these techniques in relation to transabdominal ultrasound and endoscopic retrograde cholangiography for the diagnosis of choledocholithiasis still remains somewhat uncertain.