Emergency radiology: don’t miss 4 of 8
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Cases/ChestVascular
Case 1011

Saddle pulmonary embolismWhat is the diagnosis?

Case image 1 CT 1 / 1

CT pulmonary angiogram, axial (arrows from the original source).

Image: James Heilman, MD, CC BY-SA 3.0 — source

Answer hidden. Review the images and history, decide on your diagnosis, then reveal.

Findings

  • Large filling defects within the right and left main pulmonary arteries (arrows)
  • Thrombus extends across the pulmonary arterial bifurcation — a saddle embolus

Case discussion

A saddle embolus straddles the bifurcation of the main pulmonary artery. Assess for right heart strain — an enlarged right ventricle, septal bowing and contrast reflux into the IVC — because it determines risk and the need for thrombolysis.

Recent surgery and immobility are classic risk factors. Treatment is anticoagulation, with thrombolysis or catheter-directed therapy for high-risk patients.

Encyclopedia

Pulmonary embolismObstruction of the pulmonary arteries by thrombus, usually from the deep veins of the legs, diagnosed with CT pulmonary angiography.

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