Pearls & Pitfalls for Pelvic Ultrasound
1 Incorporate bedside ultrasound into your clinical practice. It can provide you with fast, reliable data that can help guide and expedite your management plans.
2 When performing a pelvic ultrasound, always begin with a transabdominal scan to obtain a general overview of your patient’s pelvic anatomy. Use a 3-5 MHz curvilinear or phased array transducer for transabdominal imaging. Remember that a full urinary bladder provides a great acoustic window for the transabdominal scan. Don’t forget to check Morrison’s pouch for free fluid whenever there is concern for a ruptured ectopic pregnancy.
3 Have your patient empty her bladder prior to the endovaginal portion of the scan.
4 Apply a copious amount of gel over the intracavitary transducer (ICT) and then cover the probe and gel with a transducer sheath or condom. Apply another layer of bacteriostatic surgical gel on the outside of the transducer sheath at the tip of the probe.
5 Insert and advance the transducer with the indicator marker pointing anteriorly towards the patient’s pubic symphysis. Alternatively, you may let the patient insert the probe herself as this method is often less uncomfortable.
6 Scan through the entire pelvis in both the transverse and longitudinal planes. Don’t prematurely terminate your scan just because you find the answer you are looking for early on. Unexpected findings may lie in the periphery.
7 Molar pregnancies will appear as a “cluster of grapes” on high-resolution bedside ultrasonography. The complex echoic intrauterine mass will be speckled with round, hypoechoic cystic chorionic villi. The old “snowstorm appearance” of molar pregnancies refers to the images laden with artifact seen with older, low-resolution ultrasound machines.
8 Note that molar pregnancies are associated with theca lutein cysts in the ovaries. Make sure you evaluate both adnexa for the presence or absence of masses and flow.
9 Practice Makes Perfect: With bedside ultrasound, there is no substitute for experience. The more scans you do, the better you will be able to differentiate abnormal from normal, even when you may not be sure exactly what the abnormality is. You can find many ultrasound images in the ultrasound section of epmonthly.com.
Teresa Wu is the Director of Ultrasound & Simulation, and Assistant Program Director for the Maricopa Emergency Medicine Program in Phoenix, Arizona.
Brady Pregerson manages a free online EM Ultrasound Image Library and is the editor of the Emergency Medicine Pocketbook series. For more information visit ERPocketBooks.com