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Tips & Tricks for Abdominal Ultrasonography
01 Bedside ultrasound can provide you with valuable data to help you make critical diagnoses and expedite patient care. Always approach each scan with an open and inquisitive mind. You may be surprised by what you find.
02 The purpose of performing a focused, limited bedside scan is to answer a select set of questions concerning the patient’s presentation. It is important to make sure you are asking the right set of questions, and to be careful not to anchor into a diagnosis before you get all of the data back.
03 Always visualize the adjacent structures surrounding your target organ of interest. For example, when you seek out to evaluate the aorta, scan through the surrounding liver parenchyma, too. Changes in the surrounding organs can alter the appearance of your target structure, and abnormalities of adjacent structures may provide you with the reason for your patient’s symptoms.
04 When scanning through a target organ, obtain at least 4 different views of the area of interest. Use the body’s natural acoustic windows, such as the liver and the urinary bladder, to improve your views.
05 The aorta scan is best performed using the low frequency curvilinear transducer. Start with the transducer in a transverse fashion with the indicator marker pointed towards the patient’s right side. Obtain a good view of the IVC, aorta, and vertebral body.
06 Once all three structures have been identified, slide your probe over the aorta and follow it down through its bifurcation just above the umbilicus.
07 Findings suggestive of a AAA:
- Increased aortic diameter >3 cm
- Focal dilatation (1.5 times the adjacent aortic segment)
- Lack of normal tapering distally
- Presence of intraluminal thrombus
08 Do not mistake a fluid-filled loop of bowel to be an enlarged aorta. Make sure that the round, hypoechoic structure you think is the aorta doesn’t demonstrate any peristaltic movements on ultrasound.
09 When in doubt, you can always apply color-Doppler. Remember that the aorta will demonstrate pulsatile flow, whereas the IVC will show a low flow rumble of color. Bowel should not show any consistent pattern of color flow.
10 Be comprehensive with your scans. Don’t stop scanning just because you have found the answer you were looking for. Often times, interesting pathology can be discovered in the periphery of a focused scan. You may not always know exactly what you are looking at, but at least you can provide the patient with the data and knowledge to take the next best step towards improving their care.
Brady Pregerson manages a free online EM Ultrasound Image Library and
is the editor of the Emergency Medicine Pocketbook series. For more
info visit EMresource.ORG. Teresa S. Wu is the Associate
Residency Director, and Director of Ultrasound and Simulation Programs
and Fellowships, for the Maricopa EM Program in Phoenix.