Ultrasonography in the emergency setting.

US is the imaging modality of choice in many situations encountered in the Emergency Department. It is particularly useful in evaluating renal colic, pain or vaginal bleeding in the pregnant patient, and pelvic pain in the nonpregnant woman; and in diagnosing gallbladder disease, appendicitis, proximal lower extremity DVT, and pericardial effusion. The information presented in each section, including sonographic findings and the role of US, should be helpful in choosing the most appropriate test in the evaluation process.