Thank you Maz for saving these images.
This patient was transferred with a diagnosis of aortic dissection.
Type A dissections are usually difficult to see with bedside US and the gold standard is TEE or CTA. However, about 1/3 of type A dissections extend into the abdomen. So having a look in the abdomen for this time critical diagnosis is well worth the time. Finding an undulating intimal flap is highly specific for dissection (1). The flap should have independent motion. Sometimes lines may be seen within the aortic lumen simply due to slice thickness or reverberation artefact. But these usually don't have undulating motion (see last 2 images).
Epigastric aorta in trans showing a normal sized aorta (<3cm) with an anterolateral haematoma. See diagram below.
colour doppler loop of the epigastric aorta showing blood pulsing into the dissection. See image below.
Long view of the abdominal aorta showing a dissection flap with independent motion. See diagram below.
abdominal aorta long with shadows appearing due to slice thickness and reverberation artefact. Shadows do not show independent motion (see diagram below).
1. Fojtik JP, Costantino TG, Dean AJ. The diagnosis of aortic dissection by emergency medicine ultrasound.J Emerg Med. 2007;32:191–6.