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Posterior medial choroidal artery

The posterior medial choroidal artery (PMChA) is a small but clinically significant branch of the posterior cerebral artery (PCA), arising from the P2 segment. This vessel courses medially and posteriorly, supplying vital structures such as the thalamus, midbrain, pineal gland, and the choroid plexus of the third ventricle. Due to its deep location and proximity to critical neurovascular territories, understanding its anatomy and imaging features is crucial in neuroradiology, especially in the evaluation of vascular lesions, infarcts, and arteriovenous malformations.

Synonyms

  • Medial posterior choroidal artery

  • PMChA

  • Posterior medial choroidal branch

Function

  • Supplies blood to the medial thalamus

  • Provides vascularization to the pineal gland and adjacent midbrain regions

  • Supplies the choroid plexus of the third ventricle

  • Plays a minor role in the vascularization of the superior tectal plate

MRI Appearance (AI-Enhanced 3T SFOV)

T2-Weighted Imaging:

  • The artery itself is generally not visualized directly unless enlarged or involved in pathology

  • Flow void may be seen along its expected course in the perimesencephalic cistern or around the pineal region

  • Surrounding parenchyma is evaluated for ischemic changes or lesions supplied by the PMChA

  • Vascular malformations or aneurysms involving the artery may appear as signal voids or flow-related artifacts

T1-Weighted Imaging:

  • Vessel appears as a small flow void or signal loss structure along its course

  • Contrast-enhanced T1 may highlight vascular pathology such as aneurysm, thrombosis, or enhancement of the choroid plexus

  • Not routinely visualized in healthy subjects unless pathology is present

AI Enhancement Notes:

  • AI-enhanced imaging can improve detection of small-caliber arteries and subtle vascular abnormalities

  • High-resolution SFOV sequences increase confidence in tracing the artery in pathologic conditions

CT Appearance

  • Generally not visualized directly on non-contrast CT due to small caliber

  • May be appreciated as a faint hyperdense line with contrast on CT angiography (CTA), especially with high spatial resolution techniques

  • Pathologies such as acute hemorrhage, infarct, or arteriovenous malformations in its territory may be secondary signs

  • Calcifications in the choroid plexus (supplied by the artery) can be seen in older individuals

MRI images

Posterior medial choroidal artery mri 3t coronal image