Background: Endoscopic color Doppler ultrasonography (ECDUS) is a method for detecting color flow images in blood vessels. We previously reported on the usefulness of ECDUS (convex-type scanning instruments with forward -Oblique viewing) for evaluating the hemodynamics of esophageal varices. In the present study, we report the usefulness of new electronic radial ECDUS in cases of esophageal varices by comparison with convex-type ECDUS. Methods: Twenty-six patients with esophageal varices were identified and studied. The underlying pathologies of portal hypertension included liver cirrhosis (15 patients) and cirrhosis associated with hepatocellular carcinoma (11 patients). Endoscopic findings of esopha-geal varices were as follows: Cb, F3, and Ls varices in four patients; Cb, F2, and Lm varices in 21 patients; and Cb, Lm, and F1 varices in one patient. RC1 was observed in the esophagus in 14 of the 26 patients. RC2 was noted in 11 cases, and RC0 was seen in one patient. ECDUS was performed using a Pentax EG- 3630UR (forward view) with a distal tip diameter of 12mm. The instrument (electronic radial array) has a curved array scanning transducer with variable frequency (5.0, 7.5, 10.0MHz). A Hitachi EUB 6500,8500 was used for the display, providing 270° images. We monitored the color flow images of esophageal varices, paraesophageal veins, palisade veins, perforating veins, and pulsatile waves using this technique. As a control, 110 patients were examined by convex-type ECDUS. Results: (1) Color flow images of esophageal varices and paraesophageal veins were obtained in 26 of the 26 patients, whereas color flow images of perforating veins were obtained in 18 of the 26 patients (69.2% ). Color flow images of palisade veins were obtained in 12 of the 26 patients (46.2% ). (2) Color flow images of pulsatile waves were obtained in 10 of the 26 patients (38.5% ). Color flow images of pulsatile waves were detected in zero (0% ) of the 4 F3 varices, in nine (42.9% ) of the 21 F2 varices, and in the 1 (100% ) case of F1 varices. Also, color flow images of pulsatile waves were detected in seven (50.0% of the 14 RC1 varices, in two (18.2% ) of the 11 RC2 varices, and in the 1 (100% ) case of RC0 varices. (3) As a control, 110 patients were examined by convex-type ECDUS. Color flow images of esophageal varices and paraesophageal veins were obtained in 110 of the 110 patients, whereas color flow images of perforating veins were obtained in 74 of 110 (67.3% ) with convex-type ECDUS. The detection rate of palisade veins with electronic radial ECDUS (12 of the 26 patients, 46.2% )was significantly higher than with convex-type ECDUS (28 of the 110 patients,25.5% ) (P < 0.05) . The detection rate of pulsatile waves with electronic radial ECDUS (10 of the 26 cases, 38.5% ) was significantly higher than with convex-type ECDUS (3 of the 110 cases, 2.7% ) (P < 0.0001). Conclusions: Electronic radial ECDUS provides clear color flow images of blood vessels in esophageal varices with the additional advantages of forward-view optics and extended 270° views. Electronic radial ECDUS was superior to convextype ECDUS in detecting palisade veins and pulsatile waves. Background: Endoscopic color Doppler ultrasonography (ECDUS) is a method for detecting color flow images in blood vessels. We previously reported on the usefulness of ECDUS (convex-type scanning instruments with forward-Oblique viewing) for evaluating the hemodynamics of esophageal varices. In the present study, we report the usefulness of new electronic radial ECDUS in cases of esophageal varices by comparison with convex-type ECDUS. Methods: Twenty-six patients with esophageal varices were identified and studied. The underlying pathologies of portal hypertension included liver cirrhosis ( 15 patients) and cirrhosis associated with hepatocellular carcinoma (11 patients). Endoscopic findings of esopha-geal varices were as follows: Cb, F3, and Ls varices in four patients; Cb, F2, and Lm varices in 21 patients; RC1 was observed in the esophagus in 14 of the 26 patients. RC2 was noted in 11 cases, and RC0 was seen in one patient. ECDUS was perfor med using a Pentax EG- 3630UR (forward view) with a distal tip diameter of 12 mm. The instrument (electronic radial array) has a curved array scanning transducer with variable frequency (5.0, 7.5, 10.0 MHz) A Hitachi EUB 6500, 8500 was used for the display, providing 270 ° images. We monitored the color flow images of esophageal varices, paraesophageal veins, palisade veins, perforating veins, and pulsatile waves using this technique. As a control, 110 patients were examined by convex-type ECDUS Color flow images of esophageal varices and paraesophageal veins were obtained in 26 of the 26 patients, whereas color flow images of perforating veins were obtained in 18 of the 26 patients (69.2%). Color flow images of palisade veins (2) Color flow images of pulsatile waves were obtained in 10 of the 26 patients (38.5%). Color flow images of pulsatile waves were detected in zero (0%) of the 4 F3 varices, in nine (42.9%) of the 2 1Also, color flow images of pulsatile waves were detected in seven (50.0% of the 14 RC1 varices, in two (18.2%) of the 11 RC2 varices, and (3) As a control, 110 patients were examined by convex-type ECDUS. Color flow images of esophageal varices and paraesophageal veins were obtained in 110 of the 110 patients, whereas color flow The detection rate of palisade veins with electronic radial ECDUS (12 of the 26 patients, 46.2%) was significantly higher than with convex-type ECDUS (67.3%) was convex in type ECDUS 28 of the 110 patients, 25.5%) (P <0.05). The detection rate of pulsatile waves with electronic radial ECDUS (10 of the 26 cases, 38.5%) was significantly higher than the convex- type ECDUS , 2.7%) (P <0.0001). Conclusions: Electronic radial ECDUS provides clear color flow images of blood vessels in esophageal va rices with the additional advantages of forward-view optics and extended 270 ° views. Electronic radial ECDUS was superior to convex type ECDUS in detecting palisade veins and pulsatile waves.