4D-Flow MRI Assessment of Portal Hypertension and TIPS Outcomes in Cirrhosis

Inclusion Criteria: Applicable to both groups : 1. Age ≥ 18 years 2. Eligible to undergo MRI examination 3. Prior clinical evaluation completed 4. Covered by a national health insurance scheme or beneficiary thereof (excluding State Medical Aid AME) 5. Patient informed and written informed consent obtained Specific to the MASLD group : 6. Indication for TIPS validated during a multidisciplinary team meeting and documented in the patient's medical record, including one of the following: * Refractory ascites * Hepatic hydrothorax * Failure of secondary prophylaxis of variceal gastrointestinal bleeding * Preemptive TIPS * Preoperative TIPS Specific to the MASLD group : 7. Past or current exposure to metabolic risk factors (overweight, obesity, type 2 diabetes mellitus, arterial hypertension, dyslipidemia) 8. Liver stiffness \> 15 kPa measured by transient elastography 9. Liver biopsy documenting steatosis with stage 3 fibrosis or cirrhosis 10. Alcohol consumption \< 20 g/day for women and \< 30 g/day for men, assessed using validated routine clinical questionnaires Exclusion Criteria: Applicable to both groups : 1. Any contraindication to MRI (cardiac pacemaker, implantable cardioverter-defibrillator, cochlear implants, intraocular metallic foreign bodies, intracranial vascular clips). 2. Prior liver transplantation. 3. Pregnancy, breastfeeding, or women of childbearing potential not using effective contraception. 4. Individual under legal guardianship or trusteeship, or unable to provide informed consent. 5. Participation in another interventional clinical study or currently within the exclusion period following a previous ongoing study. Specific to the TIPS group 6. Patients undergoing salvage TIPS placement in the setting of hemorrhagic shock. Specific to the MASLD group 7. Other etiologies of chronic liver disease, including viral hepatitis, autoimmune liver disease, or hemochromatosis