Pediatric Radiology

, Volume 46, Issue 10, pp 1378–1383 | Cite as

Pulmonary arterial hypertension in children: diagnosis using ratio of main pulmonary artery to ascending aorta diameter as determined by multi-detector computed tomography

  • Pablo Caro-Domínguez
  • Gregory Compton
  • Tilman Humpl
  • David E. Manson
Original Article



The ratio of the transverse diameter of the main pulmonary artery (MPA) to ascending aorta as determined at multi-detector CT is a tool that can be used to assess the pulmonary arterial size in cases of pulmonary arterial hypertension in children.


To establish a ratio of MPA to ascending aorta diameter using multi-detector CT imaging suggestive of pulmonary arterial hypertension in children. We hypothesize that a defined ratio of MPA to ascending aorta is identifiable on multi-detector CT and that higher ratios can be used to reliably diagnose the presence of pulmonary arterial hypertension in children.

Materials and methods

We calculated the multi-detector CT ratio of MPA to ascending aorta diameter in 44 children with documented pulmonary arterial hypertension by right heart catheterization and in 44 age- and gender-matched control children with no predisposing factors for pulmonary arterial hypertension. We compared this multi-detector-CT-determined ratio with the MPA pressure in the study group, as well as with the ratio of MPA to ascending aorta in the control group. A threshold ratio value was calculated to accurately identify children with pulmonary arterial hypertension.


Children with documented primary pulmonary arterial hypertension have a significantly higher ratio of MPA to ascending aorta (1.46) than children without pulmonary arterial hypertension (1.11). A ratio of 1.3 carries a positive likelihood of 34 and a positive predictive value of 97% for the diagnosis of pulmonary arterial hypertension.


The pulmonary arteries were larger in children with pulmonary arterial hypertension than in a control group of normal children. A CT-measured ratio of MPA to ascending aorta of 1.3 should raise the suspicion of pulmonary arterial hypertension in children.


Ascending aorta Children Computed tomography Main pulmonary artery Pulmonary arterial hypertension Ratio 


Compliance with ethical standards

Conflicts of interest



  1. 1.
    Hoeper MM (2009) Definition, classification, and epidemiology of pulmonary arterial hypertension. Semin Respir Crit Care Med 30:369–375CrossRefPubMedGoogle Scholar
  2. 2.
    Rubin LJ (2004) Diagnosis and management of pulmonary arterial hypertension: ACCP evidence-based clinical practice guidelines. Chest 126:7S–10SCrossRefPubMedGoogle Scholar
  3. 3.
    Ng CS, Wells AU, Padley SP (1999) A CT sign of chronic pulmonary arterial hypertension: the ratio of main pulmonary artery to aortic diameter. J Thorac Imaging 14:270–278CrossRefPubMedGoogle Scholar
  4. 4.
    Chaudry G, MacDonald C, Adatia I et al (2007) CT of the chest in the evaluation of idiopathic pulmonary arterial hypertension in children. Pediatr Radiol 37:345–350CrossRefPubMedGoogle Scholar
  5. 5.
    Edwards PD, Bull RK, Coulden R (1998) CT measurement of main pulmonary artery diameter. Br J Radiol 71:1018–1020CrossRefPubMedGoogle Scholar
  6. 6.
    Karazincir S, Balci A, Seyfeli E et al (2008) CT assessment of main pulmonary artery diameter. Diagn Interv Radiol 14:72–74PubMedGoogle Scholar
  7. 7.
    Truong QA, Massaro JM, Rogers IS et al (2012) Reference values for normal pulmonary artery dimensions by noncontrast cardiac computed tomography: the Framingham heart study. Circ Cardiovasc Imaging 5:147–154CrossRefPubMedGoogle Scholar
  8. 8.
    Compton GL, Florence J, MacDonald C et al (2015) Main pulmonary artery-to-ascending aorta diameter ratio in healthy children on MDCT. AJR Am J Roentgenol 205:1322–1325CrossRefPubMedGoogle Scholar
  9. 9.
    Akay HO, Ozmen CA, Bayrak AH et al (2009) Diameters of normal thoracic vascular structures in pediatric patients. Surg Radiol Anat 31:801–807CrossRefPubMedGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  • Pablo Caro-Domínguez
    • 1
  • Gregory Compton
    • 1
    • 2
  • Tilman Humpl
    • 3
  • David E. Manson
    • 1
  1. 1.Department of Diagnostic Imaging, The Hospital for Sick Children, Department of Medical ImagingUniversity of TorontoTorontoCanada
  2. 2.Epworth Medical ImagingEpworth HospitalRichmondAustralia
  3. 3.Division of Cardiology, Department of Pediatrics, The Hospital for Sick ChildrenUniversity of TorontoTorontoCanada

Personalised recommendations