This presentation represents an attempt to provide an overview of an approach to the ultrasonographic diagnosis of gastrointestinal
diseases in three essential steps: identification, imaging, and interpretation. Positive identification of a lesion requires systemic scanning of the entire gastrointestinal tract and must be based on thorough knowledge of anatomy. Adequate use of the ultrasound equipment must include proper magnification of ultrasound images, application of harmonic imaging, and active utilization of high-frequency probes if it is to be effective in obtaining clear images with well-defined stratification of the gastrointestinal wall. A reliable sonographic diagnosis must be based on careful analysis of the image, not a cursory glance. I propose that this analysis include the following ten factors: (1) wall thickness, (2) site and distribution of the lesion, (3) wall stratification, (4) echogenicity of the lesion, (5) extramural changes, (6) peristalsis, (7) compliance and compressibility, (8) luminal stenosis or dilatation, (9) deformity, and (10) blood flow. Identification, Imaging, and Interpretation are three keys that open the way to detecting and accurately diagnosing an array of gastrointestinal disorders.