Does this CT confirm pulmonary arterial enlargement?
Yes. The pulmonary trunk is significantly larger than the adjacent aorta.
This patient has primary pulmonary arterial hypertension. What do the micronodules represent?
Pulmonary capillary haemangiomatosis.
Is there evidence of right heart strain?
Yes. The interventricular septum is bowed outwards, narrowing the left ventricle.
The enlargement main pulmonary artery is visible on frontal chest x-rays as a prominent middle 'mogul' between the aortic arch above and left atrial appendage below.
On CT, the pulmonary trunk diameter (yellow line) should be less than approximately 30mm (reported figures vary), and should be smaller than the adjacent ascending aorta (red line).
At a lower level, the inter-ventricular septum is reversed, bowed towards the left ventricle.