SUMMARY: The term hepatic encephalopathy (HE) includes a spectrum of neuropsychiatric abnormalities occurring in patients with liver dysfunction. Most cases are associated with cirrhosis and portal hypertension or portal-systemic shunts, but the condition can also be seen in patients with acute liver failure and, rarely, with portal-systemic bypass and no associated intrinsic hepatocellular disease. Although HE is a clinical condition, several neuroimaging techniques, particularly MR imaging, may eventually be useful for the diagnosis because they can identify and measure the consequences of central nervous system (CNS) increase in substances that under normal circumstances, are efficiently metabolized by the liver. Classic MR imaging abnormalities include high signal intensity in the globus pallidum on T1-weighted images, likely a reflection of increased tissue concentrations of manganese, and an elevated glutamine/glutamate peak coupled with decreased myo-inositol and choline signals on proton MR spectroscopy, representing disturbances in cell-volume homeostasis secondary to brain hyperammonemia. Recent data have shown that white matter abnormalities, also related to increased CNS ammonia concentration, can also be detected with several MR imaging techniques such as magnetization transfer ratio measurements, fast fluid-attenuated inversion recovery sequences, and diffusion-weighted images. All these MR imaging abnormalities, which return to normal with restoration of liver function, probably reflect the presence of mild diffuse brain edema, which seems to play an essential role in the pathogenesis of HE. It is likely that MR imaging will be increasingly used to evaluate the mechanisms involved in the pathogenesis of HE and to assess the effects of therapeutic measures focused on correcting brain edema in these patients.

SUMMARY: The purpose of this article is to review the current state of the art for treating symptomatic spinal fractures associated with malignant lesions and to present potential future trends in treatments for this patient population. Epidemiology, clinical presentation, and biomechanical ramifications of these lesions are summarized and treatment regimes, clinical outcomes, and complications and technical issues associated with treatments are presented. Potential future trends and new technologies for performing vertebral body augmentation in patients with metastatic spinal lesions are also discussed.

OBJECTIVE. Worldwide, the use of sonography for the evaluation of the musculoskeletal system has been growing. However, radiologists in North America have been relatively slow to incorporate musculoskeletal sonography into their practices. The purpose of this article is to show the advantages of musculoskeletal sonography.

CONCLUSION. Musculoskeletal sonography is an important complementary tool to MRI and is essential for radiologists who want to provide patients with state-of-the-art musculoskeletal imaging.

Keywords: musculoskeletal imaging - sonography

Radiopathologic update on dementias: postmortem magnetic resonance

Abstract
Neurodegenerative diseases that course with dementia represent a public health problem that is growing in importance, mostly due to the aging of the population. Imaging techniques provide essential diagnostic and prognostic information. Some classifications of these diseases have recently been modified through the incorporation of histological, immunohistochemical, and genetic criteria. This article reviews the different radiological.
KEYWORDS: Dementia; Postmortem MRI; Postmortem diagnosis; Magnetic resonance imaging; Alzheimer´s disease;