Prospective comparison of catheter-based endoscopic sonography versus standard endoscopic sonography: Evaluation of gastrointestinal-wall abnormalities and staging of gastrointestinal malignancies

Purpose Endoscopic sonography (EUS) is an important imaging modality for evaluating benign and malignant luminal gastrointestinal-tract abnormalities. The objectives of this study were to evaluate the feasibility of catheter-based EUS (C-EUS) during standard upper and lower endoscopy in patients with malignancies and other abnormalities of the gastrointestinal-tract lumen, to assess the image quality obtained with the 12.5-MHz catheter-based ultrasound transducer, and to prospectively compare the interpretations of C-EUS images with those of the standard EUS (S-EUS) images. Methods One hundred thirty-seven consecutive patients referred for EUS were evaluated with C-EUS followed by S-EUS. The patients were assigned to 1 of 2 groups: group A, patients with intramural masses or intestinal wall thickening, with biopsies negative for malignancy; and group B, patients with esophageal, gastric, duodenal, or rectal cancer referred for staging. The results of C-EUS and S-EUS were compared for each group. Results C-EUS was completed in 134 patients: 81 patients with 83 lesions in group A and 53 patients in group B. For group A, C-EUS image interpretation concurred with that of S-EUS in 74 (89%) of 83 lesions. For group B, C-EUS concurred with S-EUS for tumor depth (T) and nodal (N) classifications in 19 cases (36%) and 26 cases (49%), respectively. The depth of invasion was underestimated by C-EUS in all 34 cases in which the T classifications by C-EUS and S-EUS were discordant. In 1 of 6 patients with stenotic cancer that was nontraversable by S-EUS, C-EUS identified lymphadenopathy (incorrectly classified as N0 by S-EUS). Conclusions C-EUS was easily performed, and the C-EUS images were comparable to the S-EUS images in assessing mucosal and intramural lesions. The limited depth of penetration of the catheter-based transducer resulted in understaging the extent of tumor invasion and underestimating the nodal spread. © 2001 John Wiley & Sons, Inc. J Clin Ultrasound 29:117–124, 2001.