Radiology – MCQ 21 – Objective sign of pulmonary plethora in chest X-ray

Which is the objective sign of identifying pulmonary plethora in a chest radiograph?
A. Diameter of the main pulmonary artery > 16 mm
B. Diameter of the left pulmonary artery > 16 mm
C. Diameter of the descending right pulmonary artery > 16 mm
D. Diameter of the descending left pulmonary artery > 16 mm

Correct answer : C. Diameter of the descending right pulmonary artery > 16 mm