Although diagnostic imaging is, for the most part, the domain of radiologists, exceptions to this rule have developed. Cardiologists perform cardiac catheterization and echocardiography. Obstetricians have developed expertise in transvaginal ultrasound and fetal assessment. Why have some specialties embraced areas of imaging as theirs, while others — such as orthopedics and medicine — continue to rely on radiology? One reason is that radiologic expertise in these latter specialities is rarely required on a 24-hour basis and it can be provided without taking on an overwhelming workload. ED bedside ultrasonography, on the other hand, must be available 24 hours a day. Conditions requiring immediate (within 15 to 20 minutes) ultrasound (U/S) include expanding or leaking abdominal aneurysm, suspected ectopic pregnancy, and traumatic hemoperitoneum. When patients with these conditions are unstable they require even more rapid imaging — “real imaging” in the operating room.