Clinical Research Directory

Inclusion Criteria: 1. Age ≥18 years. 2. Confirmed diagnosis of liver cirrhosis based on clinical, biochemical, histological, or imaging criteria. 3. Ability to provide written informed consent in Arabic or English. 4. For Subgroup A: clinical indication for large-volume paracentesis with an ascitic volume of ≥5 liters. 5. For Subgroup B: confirmed hepatic hydrothorax or confirmed absence of pleural effusion on ultrasound or chest X-ray. 6. For Subgroup C: radiologically confirmed HCC by triphasic CT or MRI according to EASL/AASLD diagnostic criteria, with available CT imaging for L3 SMI analysis. Exclusion Criteria: 1. Significant pre-existing primary pulmonary disease (e.g., moderate-to-severe COPD defined as FEV1/FVC \<70% with FEV1 \<60% predicted, interstitial lung disease, pulmonary fibrosis) that independently affects diaphragmatic mechanics. 2. Recent thoracic surgery, thoracocentesis within the preceding 72 hours, or thoracic trauma. 3. Neuromuscular disease (e.g., myasthenia gravis, amyotrophic lateral sclerosis, Guillain-Barré syndrome) independently affecting diaphragmatic function. 4. Active mechanical ventilation at time of enrollment. 5. Pregnancy. 6. Inability to achieve adequate ultrasound acoustic windows (e.g., due to extreme obesity or surgical dressings). 7. Contraindications to paracentesis in Subgroup A (e.g., disseminated intravascular coagulation, bowel obstruction). 8. Prior or planned liver transplantation within the study period, which would confound longitudinal follow-up. 9. Refusal or inability to provide informed consent.