New imaging techniques for liver diseases

Abstract

Newly developed or advanced methods of ultrasonography and MR imaging provide combined anatomical and quantitative functional information about diffuse and focal liver diseases. Ultrasound elastography has a central role for staging liver fibrosis and an increasing role in grading portal hypertension; dynamic contrast-enhanced ultrasonography may improve tumor characterization. In clinical practice, MR imaging examinations currently include diffusion-weighted and dynamic MR imaging, enhanced with extracellular or hepatobiliary contrast agents. Moreover, quantitative parameters obtained with diffusion-weighted MR imaging, dynamic contrast-enhanced MR imaging and MR elastography have the potential to characterize further diffuse and focal liver diseases, by adding information about tissue cellularity, perfusion, hepatocyte transport function and visco-elasticity. The multiparametric capability of ultrasonography and more markedly of MR imaging gives the opportunity for high diagnostic performance by combining imaging biomarkers. However, image acquisition and post-processing methods should be further standardized and validated in multicenter trials.

Multiparametric MR Imaging in Abdominal Malignancies

“…Moreover, a potential role for MRE in the early assessment of tumor response to vascular disrupting agents and chemotherapy in animal models has been proposed. 113 Larger studies are necessary to confirm these promising preliminary results.…”

Liver Stiffness Measured by Two-Dimensional Shear-Wave Elastography: Prognostic Value after Radiofrequency Ablation for Hepatocellular Carcinoma

“…In addition to US elastography including 2D-SWE and TE, magnetic resonance elastography (MRE) of the liver is another noninvasive method which can be used to measure the viscoelastic properties of the liver, providing a quantitative method for the diagnosis of liver fibrosis and cirrhosis as well as accurate liver fibrosis staging [35][36][37][38][39][40]. However, although the reproducibility of MRE for liver fibrosis has been reported to be even better than that of US elastography, the cost of MRE is much higher than that of SWE [41,42]. In addition, MRE requires a longer acquisition time, and claustrophobia and the presence of iron overload in the liver are other limitations of MRE in assessing the degree of fibrosis at present [34].…”

Liver MRI: From basic protocol to advanced techniques

“…The ADC map is the graphical representation of the ratio of DW signal intensities and its measurements may discriminate between benign and malignant lesions [12,14]. There may be also potential roles in tumour grading and liver fibrosis assessment [3,15]. The ADC measurements are affected by the sequence acquisition protocol and suffer from a lack of reproducibility, particularly in respiratory triggering techniques, left liver lobe seated lesions, smaller size and lesion heterogeneity [11,12,15].…”

“…It provides a comprehensive assessment of tissue characteristics through its multiparametric capabilities, providing accurate qualitative and quantitative data [3,4].…”

“…When compared to its main competitor CT, MR has a higher contrast-to-noise ratio (CNR), lack of ionizing radiation exposure and uses contrast agents with the ability to explore both extracellular and hepatocellular compartments [2,3,5].…”