[MRT of the liver in Wilson's disease]

MR imaging features of focal liver lesions in Wilson disease

Hepatic involvement in Wilson disease (WD) manifests as a diffuse chronic disease in the majority of patients. However, in a subset of patients focal liver lesions may develop, presenting with a wide range of imaging features. The majority of focal liver lesions in patients with WD are benign nodules, but there are reports that have described malignant liver tumors or dysplastic nodules in these patients. Because of the possibility of malignant transformation of liver nodules, major concerns have been raised with respect to the management and follow-up of patients with WD in whom focal liver lesions have been identified. The assessment of liver involvement in patients with WD is generally performed with ultrasonography. However, ultrasonography conveys limited specificity so that magnetic resonance (MR) imaging is often performed to improve lesion characterization. This review was performed to illustrate the spectrum of MR imaging features of focal liver lesions that develop in patients with WD. It is assumed that familiarity with the MR imaging presentation of focal liver lesions in WD may help clarify the actual nature of hepatic nodules in patients with this condition.

Diffuse liver disease: strategies for hepatic CT and MR imaging

The liver plays several complex but essential roles in the metabolism of amino acids, carbohydrates, and lipids, as well as synthesis of proteins. The basic pathophysiology of diffuse parenchymal hepatic diseases usually represents a failure in one of these metabolic pathways. Specific parenchymal diseases can be categorized as storage, vascular, and inflammatory diseases. Cross-sectional hepatic imaging techniques, specifically multidetector computed tomography (CT) and magnetic resonance (MR) imaging, have roles in evaluation of diffuse liver disease. The prominent role of multidetector CT is primarily defined by its excellent morphologic visualization capabilities, in particular of diffuse or focal intrahepatic lesions as well as of anatomic relationships between the liver and adjacent organs. The variety of available multidetector CT scanners covers a huge spectrum of detector configurations ranging from equally sized and equally spaced detector arrays to asymmetric detector configurations, resulting in imaging protocols with unique parameters for almost each multidetector CT system. In addition to 64-detector row imaging, hepatic multidetector CT can be performed with emerging techniques such as dual-energy CT. Hepatic MR imaging has been proved to be a comprehensive modality for assessing the morphology and functional characteristics of the liver. Concurrent technical improvements as well as implementation of advanced imaging sequence designs permit high-quality examination of the liver with T1-, T2-, and diffusion-weighted pulse sequences. Three basic demands remain if MR imaging is chosen for hepatic imaging: to improve parenchymal contrast, to suppress respiratory motion, and to ensure complete anatomic coverage. Supplemental material available at http://radiographics.rsna.org/content/29/6/1591/suppl/DC1.

Significance of copper determination in late onset of Wilson's disease

BACKGROUND

Wilson's disease is an autosomal recessive disorder of copper metabolism resulting from the dysfunction of a copper transporting P-type ATPase encoded on chromosome 13. When capacity for hepatic storage is exceeded, the excess copper manifests itself in toxic action. In this article, the case of a sudden unexpected death of a 22-year-old woman, as a result of a subclinical course of Wilson's disease, is reported.

METHODS/RESULTS

A woman with no past medical history of underlying liver disease was hospitalized for nine days before death because of strong hemolytic anemia of unknown origin. Intoxication by lead, mercury, cadmium, thallium, zinc, chromium, manganese, and arsenic compounds was excluded. High levels of copper in blood and urine (AAS method) were found (blood: 3.90 microg/ml, urine: 8.10 microg/ml, 12,140 microg/24 h; normal - blood: 0.88 microg/ml, urine: 0.051 microg/ml, < 51 microg/24 h). Symptomatic treatment, aimed at multi-organ failure, was applied immediately. In spite of intensive care, the patient died. Post-mortem findings indicated the presence of anasacra and ascites, hydropericardium, brain edema, orange-like coloration of internal organs, and cirrhotic liver. Histopathological examination of liver slices revealed complete micro- and medionodular cirrhotic changes, focal central necrosis of the hepatocytes and cholestasis. The copper content in liver was 89.8 mug/g (normal: 3.58 +/- 1.71 microg/g).

CONCLUSIONS

Assessment of tissue copper content is essential for the diagnosis of Wilson's disease in the living or after death (in living it can be helpful in proper diagnosis, and after death it enables one to ascertain the cause of a sudden death). The copper level in the liver in Wilson's disease is about 25 times higher than in the healthy liver.

Liver imaging findings of Wilson's disease

Wilson's disease is a rare, autosomal-recessive inherited disorder of copper metabolism resulting in accumulation of copper in liver. The form of liver disease varies, depending on the severity of the disease at the time of diagnosis and pathological findings include fatty changes, acute hepatitis, chronic active hepatitis, cirrhosis and occasionally fulminant hepatic necrosis. Liver imaging findings reflect a wide range of physiopathological processes of the disease and also demonstrate the associated findings of cirrhosis in cases with advanced disease.

Diffuse liver disease

During the last decade, the role of the radiologist in evaluating patients with diffuse liver disease has increasingly expanded. In many cases, the management choices for the hepatologist in the imaging work-up of a patient with suspicion of a diffuse liver disease have significantly widened. In some instances, imaging may point directly to the diagnosis; in many instances, imaging helps narrow the differential diagnosis or is crucial in the follow-up of patients. Although some rare entities still have nonspecific radiologic features, the imaging pattern, in combination with appropriate clinical information, may provide the most likely diagnosis.

MR imaging in chronic hepatitis and cirrhosis

The role of magnetic resonance imaging (MRI) in the evaluation of diffuse parenchymal abnormalities of the liver has been expanded by recent technical advances of MR systems as well as the evolution of intravenous contrast media. Currently, MR is undoubtedly the most useful imaging modality for detecting the presence of chronic liver disease. Tailored sequences allow acurate depiction of specific disorders, including steatohepatitis and iron-overload states. Morphologic changes and signal intensity effects not only facilitate the diagnosis of chronic liver disease with MRI but they also help to distinguish between different etiologies, and they assist in staging the histologic severity of certain chronic conditions. Moreover, the faster MRI scanning techniques presently available permit the dynamic assessment of contrast enhancement, which permits improved characterization of focal hepatic lesions, including regenerative nodules, dysplastic nodules, and hepatocellular carcinoma (HCC). Although overlap in MRI findings still may exist among different types of chronic liver disease and among focal liver lesions, familiarity with certain specific imaging features may be diagnostic in the proper clinical setting. Finally, comprehensive MRI examination, including MR angiography and MR cholangiography, is the most sensitive and cost-effective technique for detecting extrahepatic disease, diagnosing vascular disorders, and evaluating the patient before or after liver transplantation. This article focuses on the current role of MR imaging in patients with chronic liver disease. The subjects covered include the detection and characterization of chronic hepatitis and cirrhosis, specific findings seen in steatohepatitis and certain metabolic diseases, the evaluation of extrahepatic vascular complications of cirrhosis, and patient assessment before and after liver transplantation. The characterization of hepatic masses is also included briefly. This subject is covered in greater depth elsewhere in this issue.