Liver Disease

Hemochromatosis

• Presentation - golden diabetics, hypogonadotrophic hypogonadism, arthritis

• Diagnosis = MR

  • Visceral iron causes susceptibility artifact which is what causes the characteristic findings on T2

  • Findings will be opposite of hepatic steatosis

  • In phase T2 = low signal

  • Out of phase T2 = high signal

  • Compare tissue density to skeletal muscle for good reference of signal intensity

• Primary

  • Mutation in HFE gene via C282Y or H63D mutation

    • Fe on periodic table is iron, so HFE = (H)igh (Fe) = High iron

  • Affects liver and pancreas

  • More in white people

  • Affects women later on in life (menstruation decreases iron levels)

  • Bronze diabetes

  • Does NOT affect spleen or bone marrow

• Secondary

  • Affects liver and spleen

  • Causes

    • Recurrent transfusions

    • Frequent cell turnover (hemolytic anemias, myelodysplastic syndromes)

• Hemochromatosis also causes MSK related disease affecting the

  • 2nd & 3rd MCP joints - hooked osteophytes

    • CPPD also gets hooked osteophytes

  • TFCC

• Note that on MR the liver should not be darker than the paraspinal musculature - if it is then it is abnormal

Cirrhosis and Portal Hypertension

• Gastric varicies without esophageal varicies —> classic finding in splenic vein thrombosis

Hyperdense liver

• Wilson’s

• Hemochromatosis

• Thyrotrast use (radioactive contrast agent)

• Glycogen storage disease

• Amiodarone

  • Look at lungs too

    • Chronic interstitial pneumonia predominantly affecting lung bases

      • lungs are close to liver to remember

Ferriscan

• Way to quantify amount of iron in the liver

• Iron causes increased acceleration of the transverse magnetization time of protons in water

  • Causes a concentration dependent decay (darkening) of the liver

• Can be done at 1.5T or 3T but 3T is more sensitive

• Relaxometry approach

  • T2 = signal decay constant for spin echo

  • T2* = signal decay constant for gradient echo

  • R2 = rate of signal decay for spin echo = 1/T2

  • R2* = rate of signal decay for gradient echo = 1/T2*

  • Both R2 & R2* will increase with increasing liver iron concentrations

  • The signal intensity will be measured at different echo times and then generate a decay time

• Signal intensity ration (SIR) approach

  • Measure signal intensity at fixed times and compare it to a standard value of normal tissue (paravertebral muscle)

  • Put ROI on liver and muscle and get a liver to muscle ration for each TE

    • This ratio is the compared via calculator to biopsy proven concentrations of iron in the liver

  • Not really used if relaxometry is available

• Items that can fuck this up - basically anything that causes abnormal liver parenchyma

  • Steatosis

  • Fibrosis - decreased R/R*

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