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Topic

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Right coronary artery (RCA)

The right coronary artery (RCA) arises from the right aortic sinus of the ascending aorta, just above the aortic valve. It courses between the right atrium and right ventricle within the right atrioventricular (coronary) sulcus, curving around the inferior border of the heart toward the posterior interventricular groove.

The RCA supplies the right atrium, right ventricle, sinoatrial (SA) node (≈60%), atrioventricular (AV) node (≈80%), inferior wall of the left ventricle, and the posterior third of the interventricular septum. Its distribution varies with coronary dominance:

  • Right dominant (≈80–85%) → RCA gives rise to the posterior descending artery (PDA).

  • Left dominant (≈10%) → PDA arises from the left circumflex artery.

  • Co-dominant (≈5–10%) → contributions from both RCA and LCx.

Synonyms

  • RCA

  • Arteria coronaria dextra

  • Right coronary vessel

Function

  • Supplies oxygenated blood to the right atrium and ventricle

  • Perfuses the inferior LV wall and posterior septum in right dominance

  • Provides arterial supply to the SA and AV nodes, ensuring conduction integrity

  • Plays a central role in coronary circulation balance and dominance patterns

Branches

  • Conus artery → supplies RV outflow tract

  • Sinoatrial nodal artery (in ~60%) → supplies SA node

  • Right marginal artery → supplies RV free wall

  • Posterior descending artery (PDA) → supplies posterior septum and inferior LV (in right dominance)

  • Atrioventricular nodal branch → supplies AV node

MRI Appearance

T1-weighted images (non-contrast):

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

  • Vessel wall hypointense; surrounding epicardial fat aids identification

T2-weighted images:

  • Blood remains a signal void

  • Edema from ischemia or infarction in RCA-supplied myocardium (inferior wall) appears hyperintense

STIR (Short Tau Inversion Recovery):

  • Suppresses fat, highlighting myocardial edema in RCA perfusion zones (inferior wall, posterior septum)

  • Infarcted or inflamed myocardium appears bright hyperintense

T1 Post-Contrast (Gadolinium-enhanced):

  • RCA lumen enhances brightly and homogeneously

  • Myocardial late gadolinium enhancement (LGE) demonstrates scar or infarction in RCA territory (inferior MI, posterior MI)

MRI Non-Contrast Cardiac-Gated 3D Coronary MRA:

  • ECG-gated, respiratory-navigated 3D acquisition shows RCA as a continuous bright vessel

  • Demonstrates origin from right coronary cusp, proximal/mid/distal segments, right marginal branches, and PDA

  • Useful for congenital anomalies, anomalous origin, and non-invasive RCA mapping

  • Beneficial in patients with renal impairment where contrast is contraindicated

CT Appearance

Non-contrast CT (Calcium Scoring):

  • RCA visualized for coronary artery calcium scoring

  • Calcified plaques quantified using Agatston score; critical for risk stratification

CT Coronary Angiography (CCTA):

  • Gold standard for non-invasive RCA imaging

  • High-resolution depiction of origin, proximal/mid/distal RCA, right marginal branches, AV nodal branch, and PDA

  • Detects atherosclerotic plaques, stenosis, occlusion, aneurysm, dissection, or anomalous origin/course

  • Multiplanar reformats and 3D reconstructions guide PCI, CABG planning, and risk assessment

CT images

Right coronary artery (RCA) anantomy CT axial image -img-00000-00000

CT images

Right coronary artery (RCA) anantomy CT axial image -img-00000-00000_00001

MRI image

Right coronary artery (RCA) mri axial image