Role of Grey Scale and Color Doppler in the Diagnosis of Portal Hypertension: A Comprehensive Review

Portal hypertension represents a central haemodynamic abnormality in chronic liver disease and is responsible for major complications such as variceal bleeding, ascites, splenomegaly, hepatorenal dysfunction, and hepatic encephalopathy. Current non-invasive imaging contributes substantially to early diagnosis and follow-up; ultrasound (grey scale and colour Doppler) is the most commonly performed modality due to the availability of real-time haemodynamic monitoring and its ability to detect structural and functional derangements. These modalities allow real-time visualisation of portal venous anatomy and dynamic assessment of flow direction, velocity, and collateral circulation, while also capturing parenchymal alterations that reflect disease severity. Although operator dependence and technical limitations can affect diagnostic accuracy, recent advances, including contrast-enhanced ultrasonography, elastography, tissue harmonic imaging, and AI-assisted flow analysis, have markedly strengthened the non-invasive evaluation of portal hypertension. This narrative review synthesises the current evidence on the anatomical and haemodynamic basis of portal hypertension, the diagnostic role of grey-scale and colour Doppler ultrasound, advanced sonographic tools, and evolving technologies that promise to refine prognostication and therapeutic monitoring.