Palla sign of pulmonary embolism

Lungs and pleural spaces are clear. Prominent right descending pulmonary artery (Palla sign). Heart size is normal.

Extensive bilateral pulmonary arterial filling defects identified. Partial filling defect extends within the distal right main pulmonary artery, with further extension throughout the pulmonary vascular tree within the right upper, middle and lower lobes to the subsegmental level. On the left, thrombus is demonstrated within the distal aspect of the left upper and lower lobar arteries, also with further extension throughout innumerable pulmonary arteries throughout the left lung to the subsegmental level.

Evidence of right ventricular strain, with RV/LV ratio 2.0 (normal is <1.0). The pulmonary trunk is not dilated. Mild coronary arterial calcification. No pericardial effusion.
No lymphadenopathy by CT size criteria.

The lungs and pleural spaces are clear, with no consolidation, pneumothorax or pleural effusion.

Small hiatus hernia noted. The remainder of the imaged upper abdominal organs appear grossly normal. Unremarkable appearance of the imaged soft tissues of the neck.
No suspicious osseous lesion.

IMPRESSION

Large burden pulmonary emboli extending throughout the right and left lungs from the level of the main pulmonary artery on the right and the lobar arteries on the left, through to the level of the subsegmental arteries bilaterally. There is evidence of associated right ventricular strain.