Couch, Tyler J.; Beck, Gerald J.; Berman-Rosenzweig, Erika; Jeffrey Carr, J.; Erzurum, Serpil C.; Frantz, Robert P.; Hassoun, Paul M.; Hill, Nicholas S.; Horn, Evelyn M.; Lempel, Jason K.; Leopold, Jane A.; Nian, Hui; Ray, David N.; Rischard, Franz P.; Schwalbach, Kevin T.; Terry, James G.; Hemnes, Anna R. (2026).听.听Annals of the American Thoracic Society, 23(4), 494鈥�505.听
This study examines whether the size of the聽pulmonary artery (PA)鈥攖he blood vessel that carries blood from the heart to the lungs鈥攎easured on聽CT scans聽can help indicate the presence and severity of聽pulmonary hypertension (PH), a condition where blood pressure in the lungs is abnormally high. Earlier research linked enlarged PA size to more severe PH, but it was unclear how well this relationship holds for milder cases or what it means for patient outcomes.
Researchers analyzed data from nearly 700 individuals with different types of PH and compared them with similar people without the condition. They found that larger PA size, as well as the ratio of PA size to the nearby aorta (PA:aorta ratio), was strongly associated with higher聽mean pulmonary artery pressure (mPAP)鈥攁 key measure of disease severity obtained through an invasive test called聽right heart catheterization. Importantly, PA size increased steadily from people without PH to those with mild and then more severe disease.
The study also showed that larger PA measurements were linked to worse outcomes: patients with bigger pulmonary arteries had a higher risk of needing a heart or lung transplant or dying over time. While PA size alone is not a perfect diagnostic tool, it provides useful, noninvasive information that can help assess disease severity and prognosis. Overall, these findings suggest that simple measurements from routine CT scans can offer valuable insight into both the presence and progression of pulmonary hypertension.
Figure 1
Measurement of the axial PA and aorta diameters (top left), tubular PA area (top right), right PA diameter and area (bottom left), and left PA diameter and area (bottom right). Abbreviations: Ao, aorta; LPA, left pulmonary artery; PA, main pulmonary artery; RPA, right pulmonary artery.