Ultrasound evaluation of abdominal aortic aneurysms.

Forty-eight patients undergoing elective repair of an abdominal aortic aneurysm were randomly selected for correlation of diagnosis of aneurysm and aneurysm size as determined by direct surgical measurements, ultrasound examination, and lumbar spine X-ray. The preoperative diagnosis was confirmed by lumbar spine plain films in 72% of patients and by B-mode ultrasound in all of patients. Aneurysm size could be measured by lumbar spine X-ray in 55% of patients and with gray-scale B-mode ultrasound in all of patients. The average difference between surgically measured and roentogenographically determined aneurysm size was 1.5 cm in the transverse diameter and 0.87 cm in the anteroposterior diameter of the aneurysm. The average difference between surgically measured aneurysm size and ultrasound-determined external wall diameter of the aneurysm was 0.42 cm in the transverse diameter and 0.29 cm in the anteroposterior diameter. From these data we conclude that gray-scale B-mode ultrasound of the aorta is a more sensitive and accurate method of assessing abdominal aortic aneurysms than is the use of lumbar spine X-ray.