Posterior Anterior (PA) position is with the patients stomach facing the cassette and the patients back towards of the x-ray machine. This distance diminishes the effect of beam divergence and magnification of structures closer to the x-ray tube.
- ↑ Spencer B. Gay, M.D., Juan Olazagasti, M.D., Jack W. Higginbotham, M.D., Atul Gupta M.D., Alex Wurm M.D., Jonathan Nguyen M.D. "Introduction to Chest Radiology: Positioning." University of Virginia Health Sciences Center: Department of Radiology. http://www.med-ed.virginia.edu/courses/rad/cxr/technique3chest.html