The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs. It is the only artery in the human body that carries deoxygenated blood. The pulmonary trunk (TP) starts at the pulmonary valve, is 5cm in length and 2cm in diameter. Hereafter, the trunk splits into two main branches, the left (APS), and right pulmonary artery (APD), which transport the deoxygenated blood further into the corresponding lungs.

Pulmonary artery dimensions
Region of measurement | Reference range | Mildly abnormal | Moderately abnormal | Severely abnormal |
---|---|---|---|---|
1cm below pulmonic valve | 1.5–2.1 | 2.2–2.5 | 2.6–2.9 | ≥3.0 |

References
Br Heart J. 1986 Jul;56(1):33-44 Orphanet J Rare Dis. 2014 Dec 10;9:203