Non-alcoholic fatty liver disease (NALFD) is a burgeoning global health problem, and the assessment of disease severity remains a clinical challenge. Conventional imaging and clinical blood tests are frequently unable to determine disease activity (the degree of inflammatory change) and fibrotic severity, while the applicability of histological examination of liver biopsy is limited. Imaging platforms provide liver-specific structural information, while newer applications of these technologies non-invasively exploit the physical and chemical characteristics of liver tissue in health and disease. In this review, conventional and newer imaging-based techniques for the assessment of inflammation and fibrosis in NAFLD are discussed in terms of diagnostic accuracy, radio-pathological correlations, and practical considerations. In particular, recent clinical studies of ultrasound (US)-based and magnetic resonance elastography techniques are evaluated, while the potential of contrast-enhanced US and magnetic resonance spectroscopy techniques is discussed.
The development and application of these techniques is starting to reduce the clinical need for liver biopsy, to produce surrogate end-points for interventional and observational clinical studies, and through this, to provide new insights into the natural history of NAFLD.