To evaluate the efficiency of ultrasound with IV contrast and compare this with the Computed Tomography in acute flank pain patient at Emergency Department.

Acute flank pain is a common chief complaint in emergency departments (ED), but it is a challenge for physicians in ED to accurately diagnose. It can cause variable diseases and is in many cases lethal (e.g. aortic dissection, ruptured aortic aneurysm, renal artery dissection, ruptured tumor, etc). The computed tomography scan with IV contrast is an ideal tool to diagnose due to its high sensitivity and specificity and is a golden standard examination. However, currently point-of-care ultrasound is routinely used as first-line technique. As this procedure is non-invasive and has no radiative effect, it is considered more logical, especially for those critical patients who are not able to move and perform the CT scan. Furthermore, the iodine contrast of CT scan is known as renal toxicity and should be used with caution in patient with hyperthyroidism and allergy to the contrast. The radiation of CT scan would be harmful to the pregnant patient as well.

IV contrast ultrasound is a novel technique nowadays and it is widely used in diagnosing breast, liver, renal and pancreatic tumors. The ultrasound contrast using air microbubbles could enhance the scanning quality and also has high sensitivity and specificity. In ED, ultrasound with contrast now could be applied to the abdominal trauma and pediatric injury. For those patients with poor renal function, thyroid disease and pregnant women who cannot undergo IV contrast CT, IV contrast ultrasound provides a faster and safer way to evaluate patients in ED. We compared CT and ultrasound with IV contrast to determine the difference in efficiency between both examinations.

Inclusion Criteria:

• Acute flank pain who visit ER

Exclusion Criteria:

• Younger than 18 years old
• Known allergy to contrast