Noninvasive and Invasive Methods for the Diagnosis of Portal Hypertension.

Portal hypertension is a complex and multifaceted condition that arises from increased resistance to portal blood flow, often secondary to prehepatic, intrahepatic, or post hepatic etiologies. The most common cause of portal hypertension in the United States is cirrhosis, which leads to structural and dynamic changes in the liver, exacerbating portal resistance and triggering a cascade of complications. Accurate diagnosis and management are critical to mitigating these risks and improving patient outcomes. Noninvasive imaging techniques, including ultrasound, CT, MRI, and elastography, have revolutionized the diagnosis and monitoring of portal hypertension. These modalities provide qualitative and quantitative measures of liver and spleen stiffness, portal vein flow, and morphological changes, enabling early risk stratification and intervention. Invasive techniques, such as hepatic venography with pressure measurement, remain the gold standard for diagnosing portal hypertension, particularly in for cases where in which noninvasive methods are inconclusive. Direct portal pressure measurement, although more invasive than these other techniques, is occasionally necessary in specific clinical scenarios. Liver biopsy, whether percutaneous, transjugular, or transfemoral, remains a crucial tool for histopathological diagnosis and guiding treatment strategy guidance, particularly in cases of chronic liver disease. Diagnosis of portal hypertension, which involves accurate measurement of portal pressure, is essential for early risk stratification and effective management. The available noninvasive and invasive techniques for the diagnosis of portal hypertension are reviewed here.