Focal liver lesions: characterization with nonenhanced and dynamic contrast material-enhanced MR imaging.

Abstract

Dynamic contrast-enhanced MR imaging is a useful adjunct for characterization of hepatic lesions. Knowledge of clinical history still has a decisive effect on interpretation of MR images of the liver.

Pyogenic hepatic abscesses: MRI findings on T1- and T2-weighted and serial gadolinium-enhanced gradient-echo images

“…This pattern of signal intensity and enhancement change has also been observed in association with several benign and malignant focal lesions not associated with inflammation, and in these cases is usually wedge shaped as well (5,8,14,15). The main differential diagnostic considerations of hepatic abscesses are benign or malignant focal liver lesions that possess ring enhancement, including metastases, hepatocellular carcinoma, and lymphoma (8,9,16). In many of these lesions the ring enhancement observed on immediate post-gadolinium images progresses in a centripetal fashion with an increase in thickness of enhancing tissue, usually associated with decrease in intensity on delayed images (8,9).…”

“…The main differential diagnostic considerations of hepatic abscesses are benign or malignant focal liver lesions that possess ring enhancement, including metastases, hepatocellular carcinoma, and lymphoma (8,9,16). In many of these lesions the ring enhancement observed on immediate post-gadolinium images progresses in a centripetal fashion with an increase in thickness of enhancing tissue, usually associated with decrease in intensity on delayed images (8,9). Transient perilesional hepatic parenchymal enhancement may also be observed in metastases and lymphoma (13,16).…”

“…Focal liver lesions are well characterized by dynamic gadolinium-enhanced imaging, with images acquired in the early, intermediate, and late phases post injection (8,9). To our knowledge, the dynamic imaging features of pyogenic liver abscesses on gadolinium-enhanced images have not been described previously.…”

The detection and discrimination of malignant and benign focal hepatic lesions:T2weightedvsdiffusion-weighted MRI

“…For the detection and characterisation of hepatic lesions, CT and MRI are usually employed [1,2]. MRI, T 1 weighted, T 2 weighted and gadoliniumenhanced T 1 weighted imaging have been commonly utilised [3,4].With rapid progress of the use of parallel imaging techniques such as sensitivity encoding (SENSE), the quality of diffusion weighted single-shot echo-planar imaging has improved [5]. Diffusion-weighted MRI of the abdomen has become possible by the use of this technique, which reduces acquisition time, minimises echo-planar imaging artefacts and improves the quality of images [5].…”

Hepatic alveolar echinococcosis: a diagnostic challenge

“…On MRI it is seen as a hypointense mass on T1-weighted images and as a hyperintense mass lesions are hypovascular, they show a diminished late enhancement on contrast-enhanced dynamic imaging (12,13).…”