Image of the Month July 2025: Pulmonary vein sign due to acute pulmonary embolism

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Author

Marta Peverelli,1 Jason M Tarkin,1 Deepa Gopalan3

1Division of Cardiology, University of Cambridge

3Department of Radiology, Cambridge University Hospitals NHS Trust

Case history

A 53-year-old man presented to the Emergency Department with leg and chest pain, and breathlessness. Cardiorespiratory examination and electrocardiogram were normal. D-dimer was elevated (1887; NR <230 ng/mL) and COVID-19 screen negative. Ultrasound confirmed a right femoral vein thrombosis. CT pulmonary angiography showed multiple pulmonary emboli, including a large embolism in the distal right main pulmonary artery (A: transverse, C: coronal; orange arrows) causing right middle (RML) and lower lobe (RLL) occlusion. Lack of opacification in the right inferior pulmonary vein (B: transverse; D: volume-rendered; blue arrows; RIPV) was incorrectly interpreted as thrombus extending into the left atrium (LA). Echocardiography showed no thrombus. Hypodense pulmonary vein filling defects on CT can occur in acute pulmonary embolism due to diminished venous return. Filling defects are typically observed in the lower pulmonary veins when there is proximal pulmonary artery occlusion. This appearance (known as the “pulmonary vein sign”) can mimic venous thrombosis.

 

Questions

  1. The ‘pulmonary vein sign’ is typically seen in the lower pulmonary veins during pulmonary arterial phase imaging [TRUE/FALSE]
    1. TRUE
    2. FALSE
  2. Which of the following is NOT a main cause of hypodense pulmonary vein filling defects on CT? [Select one option]
    1. Acute PE
    2. Proximal chronic thomboembolic pulmonary hypertension (CTEPH)
    3. PV stenosis
    4. Pulmonary arterial hypertension
    5. Acute on chronic pulmonary embolism
  1. Which are radiological features of acute pulmonary embolism on CT?
    1. Filling defects in branches of the pulmonary arterial system
    2. RV dilatation
    3. Pulmonary vein sign
    4. Pulmonary infarction
    5. All of the above

 

 

 

(Answers:a,d,e)

 

Reference:

1.         Souza, L.V.S., et al., “Pulmonary Vein Sign” for Pulmonary Embolism Diagnosis in Computed Tomography Angiography. Lung, 2017. 195(6): p. 769-774.

2.         Gopalan, D., et al., Pulmonary Vein Sign on Computed Tomography Pulmonary Angiography in Proximal and Distal Chronic Thromboembolic Pulmonary Hypertension With Hemodynamic Correlation.J Thorac Imaging, 2023. 38(3): p. 159-164.

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