INTEROBSERVER AND INTEREQUIPMENT VARIABILITY OF ECHO-DOPPLER EXAMINATION OF THE PORTAL-VEIN - EFFECT OF A COOPERATIVE TRAINING-PROGRAM

The aim of this study was to assess the interobserver, interequipment, and time-dependent variabilities of echo-Doppler measurements of port al blood dow velocity (PBV), portal vein diameters (PVDs) and their de rived parameters, portal blood flow (PBF), and congestion index (CT) i n cirrhotic patients. The influence of a cooperative training program of the operators on the reproducibility of the results was also invest igated. The echo-Doppler parameters were independently measured in 15 patients by four skilled operators, using four echo-Doppler machines ( Acuson, ATL, Hitachi-Esaote, Toshiba. Eight of the 15 patients were re studied after 15 days by the same operators using only one machine. Si gnificantly different values of PBV, PBF, and CI were obtained, PBV va riance was equipment-related (32%) and operator-related in a smaller p ortion (5%). No systematic effect related to the time of investigation was found After training to define a precise protocol, new measuremen ts were performed by four operators on 8 different patients. No signif icant differences were found among the operators for any of the parame ters and the 95% confidence limits (CL) and coefficients of variation (CV) of PBV showed a marked decrease (CL from +/-26.4% to +/-15.6%). T hese results indicate that (1) a significant systematic variability ex ists between Doppler measurements with different equipment; (2) there is no significant time-dependent systematic variability of Doppler mea surements; and (3) a cooperative training program reduces the interobs erver variability for direct measurements, such as PBV.