Home Hemochromatosis Iconotech DICOM softwares
 
 
Summary
  • Introduction
  • Technique
  • Indications
  • Results

  •     - .5T
        - 1T
        - 1.5T
  • Spleen...
  • References
  •  
     
     
    Iron and liver. Place of MRI.
    Yves Gandon - Medical Imaging, Rennes, France.

     
     
       Genetic hemochromatosis

    The diagnosis of genetic hemochromatosis is now easy to confirm by using the specific genetic test. Before this test, the diagnosis was based on a liver iron concentration to age ratio greater than 2. Then an accurate quantification of LIC was important. Now an accuracy of liver iron content calculation could be replace, in this patient population, by the level of ferritinemia which is pretty well correlated to LIC. Phlebotomies are then indicated and the blood quantity substracted in order to normalize blood tests will confirm the estimation given by the initial hyperferritinemia. MRI can help, in some particular patients with an associated disease (virus C, inflammation...), to estimate liver iron content but there is no need to such a study in the typical presentation.

       Other non-transfusional iron overload

    In non-genetic iron overload, the place of MRI is more important. Biopsy is still indicated when it is needed to detect an underlying liver disease (cirrhosis or hepatitis C). However, if no clinical context can evoked such a disease, MR detection and quantification of liver iron overload must be prefered.

    One of the most frequent cause in western countries is the so-called dysmetabolic hepatosiderosis. This recently described disease associates a dysmetabolic syndrom (overweight, steatosis, dyslipidemia, glucose metabolism dysregulation) and a liver iron overload. This last one is usually moderate. A slight increase of splenic iron is then frequently associated. The mechanism is still unclear.


       Practical approach

    Dealing with abnormal iron serum tests, the first step is to check the transferrin saturation coefficient. If it's greater than 45% a genetic test is indicated. A positive result leads to the diagnosis of genetic hemochromatosis. A liver biopsy is only indicated if there is some arguments in favor of associated fibrosis. This can only be seen when one of following items is true:
    • hyperferritinemia greater than 1000 UI,
    • hepatomegaly,
    • hepatic cytolyse.
    The presence of a fibrosis increases potential risks.

    In other circunstances (transferrin saturation coefficient below 45% or negative genetic test), dealing with a hyperferritinemia, the first step is to eliminate an increase of ferritinemia which is not related to an iron overload (acute inflammation, cytolyse, cirrhosis...). Then there is (roughly) 3 possibilities : anemia with ineffective erythropoiesis, hepatitis (and a liver biopsy is more suitable than a MR study) or dysmetabolic hepatosiderosis (and a MR study is then preferable).
     

      Details on MR protocol...  
     

    Update: June 10th, 2001 Write to the webmaster