MR Imaging of Liver Fibrosis: Current State of the Art

Abstract

Chronic liver disease is a major public health problem worldwide. Liver fibrosis, a common feature of almost all causes of chronic liver disease, involves the accumulation of collagen, proteoglycans, and other macromolecules within the extracellular matrix. Fibrosis tends to progress, leading to hepatic dysfunction, portal hypertension, and ultimately cirrhosis. Liver biopsy, the standard of reference for diagnosing liver fibrosis, is invasive, costly, and subject to complications and sampling variability. These limitations make it unsuitable for diagnosis and longitudinal monitoring in the general population. Thus, development of a noninvasive, accurate, and reproducible test for diagnosis and monitoring of liver fibrosis would be of great value. Conventional cross-sectional imaging techniques have limited capability to demonstrate liver fibrosis. In clinical practice, imaging studies are usually reserved for evaluation of the presence of portal hypertension or hepatocellular carcinoma in cases that have progressed to cirrhosis. In response to the rising prevalence of chronic liver diseases in Western nations, a number of imaging-based methods including ultrasonography-based transient elastography, computed tomography-based texture analysis, and diverse magnetic resonance (MR) imaging-based techniques have been proposed for noninvasive diagnosis and grading of hepatic fibrosis across its entire spectrum of severity. State-of-the-art MR imaging-based techniques in current practice and in development for noninvasive assessment of liver fibrosis include conventional contrast material-enhanced MR imaging, double contrast-enhanced MR imaging, MR elastography, diffusion-weighted imaging, and MR perfusion imaging.

Morphometric changes in liver cirrhosis: aetiological differences correlated with progression

“…Although fibrosis is a common change in cirrhosis, its histological pattern varies, depending on the underlying aetiology. 22 For example, the fibrous septa bridging portal triads and central veins are often seen in viral infection-related cirrhosis. On the other hand, cholestasis-induced liver injury shows biliary interface hepatitis including fibroplasia in the portal area, while perivenular and perisinusoidal fibrosis is commonly seen in alcoholic and NASH-related cirrhosis.…”

Molecular magnetic resonance imaging of activated hepatic stellate cells with ultrasmall superparamagnetic iron oxide targeting integrin αvβ3 for staging liver fibrosis in rat model

“…10,11 However, factors such as parenchymal inflammation, steatosis, hepatic vascular congestion, cholestasis, and portal hypertension may affect the accurate measurement of stiffness. [12][13][14] Another advanced MRI technique, diffusion-weighted imaging, allows monitoring the motion of extracellular pure water molecules by measuring apparent diffusion coefficient that may reflect microstructural changes in region of interest (ROI) and has been shown to be decreased in moderated or advanced fibrosis. 15 The potential limitation is that these MRI-based techniques indirectly reflect relationship between their measurements and liver fibrosis, and can be confounded by a variety of factors.…”

Editorial: A New Spin on Magnetic Resonance Elastography

“…However, it is operator dependent and may be less reliable in morbidly obese patients. Point shear-wave elastrography is similar to FibroScan but requires more expertise, is less well validated, and is not a point of care test ( 17,18,30 ). 2D MRE has the advantage of examining a larger area of the liver, is operator independent, and has excellent accuracy (17)(18)(19)29,31 ).…”