Gastrointestinal sonography.

The contribution of routine gray-scale sonography in the gastrointestinal tract has been augmented by the addition of duplex Doppler and, more recently, color Doppler imaging. Many recent reports focus on the deep abdominal applications of these modalities. Although duplex tracing remains the basis of most diagnoses, the use of color Doppler imaging has facilitated the performance of these examinations. Endosonography performed with high-resolution transducers in the lumen of the gut is another exciting and expanding area. Staging of gastrointestinal tumors is the major application of this modality. Future sonographic developments include the promise of contrast agents.