Educational Content: This article is for informational purposes only and does not constitute medical advice. Always consult a healthcare provider for diagnosis and treatment.
Definition of Posteroanterior (PA)
Medically reviewed by Min Clinic Staff | Updated: January 2026
Posteroanterior (PA): In anatomy, posteroanterior (PA) means from back-to-front. For example, a PA X-ray of the chest is taken from back-to-front.
PA in this respect is the opposite of AP, which stands for anteroposterior: from front-to-back.