As fast high-resolution total body computed tomography (CT) scanners have proliferated in hospitals and radiologists' offices across the country, they have tended to eclipse the usefulness of sonography in abdominal and thoracic diagnosis. This paper discusses some of the limitations of CT techniques as applied to common abdominal and thoracic problems. Emphasized here are situations wherein a quick examination with a portable real-time ultrasound device while the patient is on the CT table can result in a definitive CT report.