The essay comprises the reviwing of the anatomy of potal venous system , PathogenesisOf Portal hypertension, Clinical Diagnosis of Portal Hypertension, Classification Of PortalHypertension. Then reviwing Principles Of MR Angiography and MRA Techniques both:Non-Contrast-Enhanced Techniques and Contrast-Enhanced Techniques then MRAReconstruction Techniques, then the basics of Flow Measurement With Phase-Contrast MRImaging and MR Angiography aplications of the Portal Venous System .The Doppler Technique and findings regarding the Portal System, then Comparing bothPhase-Contrast Magnetic Resonance Angiography and Color Doppler Ultrasonography withsome illusteative cases