Topics

Topic

design image
Right pulmonary artery

The right pulmonary artery (RPA) is the longer and larger branch of the pulmonary trunk, carrying deoxygenated blood from the right ventricle to the right lung. It arises at the bifurcation of the pulmonary trunk at the level of T5–T6, passes horizontally to the right across the mediastinum, and enters the right lung at the hilum.

Anatomically, the RPA passes posterior to the ascending aorta, superior vena cava (SVC), and right main bronchus. At the hilum, it divides into upper lobar branches (to the right upper lobe) and interlobar branches, which further subdivide to supply the middle and lower lobes.

The RPA plays a central role in pulmonary circulation, delivering the full cardiac output from the right ventricle (together with the left pulmonary artery) to the lungs for oxygenation. Clinically, it is important in pulmonary embolism, pulmonary hypertension, congenital anomalies, and surgical interventions such as lung transplantation and pulmonary endarterectomy.

Synonyms

  • RPA

  • Right branch of pulmonary artery

  • Arteria pulmonalis dextra

Function

  • Carries deoxygenated blood from the pulmonary trunk to the right lung

  • Divides into segmental arteries that match the bronchopulmonary segments

  • Plays a key role in gas exchange circulation

  • Serves as a major landmark in thoracic imaging and cardiothoracic surgery

Branches

  • Upper lobar branch → right upper lobe

  • Interlobar artery → courses with bronchus intermedius, gives rise to middle and lower lobe branches

  • Segmental arteries follow bronchopulmonary segments

MRI Appearance

T1-weighted images:

  • Flowing blood appears as a signal void (black lumen)

  • Vessel wall hypointense; surrounding mediastinal fat hyperintense, providing contrast

T2-weighted images (normal):

  • RPA lumen appears as a signal void due to flow

  • Thrombus appears intermediate to hyperintense, depending on clot age

T2 TRUFISP (cardiac/respiratory-gated):

  • RPA appears as a bright, well-defined tubular structure with cine-like flow imaging

  • Useful for assessing pulmonary hypertension, stenosis, or extrinsic compression

STIR (Short Tau Inversion Recovery):

  • Suppresses mediastinal fat, highlighting vessel and surrounding pathology

  • Detects perivascular edema, inflammation, or tumor extension

T1 Post-Contrast (Gadolinium-enhanced MRI):

  • RPA lumen shows bright homogeneous enhancement

  • Filling defects correspond to pulmonary embolism, stenosis, or tumor thrombus

  • Useful for MR angiography of pulmonary arteries

MRI Non-Contrast 3D Cardiac-Gated Imaging (Whole-heart):

  • Depicts the origin, course, and branches of the RPA in 3D without contrast

  • Helpful in congenital heart disease, pulmonary artery anomalies, or when gadolinium is contraindicated

MRA (Magnetic Resonance Angiography):

  • Contrast-enhanced MRA provides high-resolution 3D visualization of RPA and its branches

  • Detects stenosis, aneurysm, anomalous origin, or embolic disease

  • Important in preoperative and interventional planning

CT Appearance

CT Coronary Angiography (CCTA) / Pulmonary CT Angiography (CTA):

  • Gold standard for RPA imaging

  • Opacified lumen clearly shows origin, course, bifurcation into lobar and segmental arteries

  • Detects pulmonary embolism, pulmonary hypertension (dilatation), stenosis, aneurysm, or congenital anomalies

  • 3D and multiplanar reconstructions allow precise surgical and interventional planning

  • Differentiates RPA pathology from mediastinal masses or lymphadenopathy

CT images

Right pulmonary artery anatomy CT coronal image -img-00000-00000

CT images

Right pulmonary artery anatomyct axial image -img-00000-00000

MRI images

Right pulmonary artery anatomy mri coronal image -img-00000-00000

MRI images

Right pulmonary artery mri image