Calcul de la concentration hépatique et cardiaque en fer

Liver and myocardial iron overload


Quantification of high liver iron concentration
(> 300 µmol/g dw/w)
by Magnetic Resonance Imaging :
Add-in sequence to
Gandon's protocol

Purpose : Measurement of high liver iron concentration (LIC) with a routine MR scan at 1.5 T

Iron overload decreases signal intensity of the liver while muscle signal intensity remains unchanged. By measuring signal intensity ratio between liver and paraspinal muscle, it is possible to obtain an estimation of  LIC. After RF excitation of the liver, the signal  is recorded during the echo time (TE). For slight liver iron overload the decrease in signal intensity is depicted only for long echo time while the signal intensity of the liver remains unchanged for short TE. For high iron overload, the signal intensity of the liver decreases with short TE while the signal intensity is zero on long TE. Therefore several acquisitions with different TE are necessary to calculate the liver iron concentration.

Iron overload and signal intensity

Gandon et All (1) described 5 sequences to calculate LIC up to 375µmol/g dw with a TE of 4 ms or longer. For higher concentration, in particular in hematologic diseases,  it is necessary to use a shorter TE.  We describe here a sequence with TE = 1.8 ms that allow quantification up to 800 µmol/g dw.

This 6
th  sequence must be performed in all patients when LIC calculated with Gandon's protocol is above 300 µmol/g dw. 

MR sequence for high iron concentration (1.5 T)

Gradient echo sequence - TE = 1.8 ms - TR =  48 ms - Flip = 60°
Thickness = 15 mm -  FOV = 450 mm - breathold

Measurement of signal intensities
Calculate the signal intensity of the liver (siL) and the signal intensity of the paraspinal muscle on the same slice (siM) and siL/siM ratio.

Regions Of Interest ROI

Liver Iron Concentration
To obtain the liver iron concentration (> 300 µmol/g dw) use the following formula :

Liver Iron Concentration µmol/g dw = 937 - (537 x siL/siM)

Liver Iron Concentration mg/g dw = 52.6 - (30.2 x siL/siM)

This formula is based on 24 biopsies with an excellent correlation ( R = -0.85 ).


You an use the following software to compute iron concentration (freeware, windowsr)

Software, open or download it.

1 Gandon Y, Olivie D, Guyader D, Aube C, Oberti F, Sebille V, Deugnier Y.    
Non-invasive assessment of hepatic iron stores by MRI.
Lancet. 2004 Jan 31;363(9406):357-62.

2 Rose C, Vandevenne P, Bougreois E, Cambier N, Ernst O
Liver iron content Assessment by routine and simple Magnetic Resonance Imaging (MRI) procedure in higly transfused patients.
European Journal of Haematology (Submitted)

Olivier ERNST      Université Lille II (France)
Christian ROSE     Université Catholique de Lille (France)

01 - 2006

Key words : liver iron hemochromatosis thalassemia MRI magnetic resonance imaging quantification