Hilum convergence sign

Last revised by Francis Deng on 17 Mar 2020

The hilum convergence sign is a useful chest radiograph sign to distinguish the cause of a bulky hilum as due to pulmonary artery dilatation or to a juxtahilar mass, including nodal enlargement. 

If pulmonary vessels appear to converge centrally towards the lateral margin of the abnormal 'bump', then the hilar opacity is an enlarged pulmonary artery 1.

If vessels do not converge towards the opacity and instead converge more towards the waist of the heart, then the opacity is due to a hilar/mediastinal mass. The converging vessels can be traced through the opacity, indicating the related hilum overlay sign.


Authors differ as to which of the aforementioned findings constitutes a 'positive' or 'negative' hilum convergence sign. Some write that the hilum convergence sign refers to the convergence of vessels onto the opacity, consistent with vascular dilatation, whereas vessels would not converge into a hilar mass 4-6. Others state the opposite: hilum convergence sign refers to vessels converging towards the waist of the heart, indicating a hilar mass 2. Others, following the original description, do not specify 1,3,7.

History and etymology

Benjamin Felson (1913-1988) was an American radiologist who first described this sign, initially called the hilus bifurcation sign 3,7.

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