Comparison between signal-to-noise ratio, liver-to-muscle ratio, and 1/T2 for the noninvasive assessment of liver iron content by MRI.
OBJECTIVE
To compare different MRI-derived parameters, i.e., liver signal-to-noise ratio (LSNR), liver-to-muscle ratio (LMR) and liver transversal relaxation rate (R2), in terms of their correlation with the ex vivo determined iron content in an experimental model of liver iron overload.


METHODS
Multi-echo spin echo (SE) images of the liver were acquired at 4.7 T from a group of 33 male wistar rats subjected to a high iron content diet for feeding periods ranging from 2 to 50 days. Liver transversal relaxation time, liver signal-to-noise ratio, and liver-to-muscle ratio were measured over the same region of interest in order to get a direct comparison between these parameters. After MRI experiments, the rats were sacrificed and the liver iron content was measured ex vivo by atomic absorption spectroscopy.


RESULTS
The iron content is better correlated to the LSNR than to the other parameters (LMR, R2).


CONCLUSIONS
The finding that liver signal-to-noise ratio is better correlated to the iron content than the liver T2 relaxation rate is relevant for clinical applications of MRI because a T2 determination is more time-consuming, both for acquisition and postprocessing of images, than a simple SNR determination.
Institute of Medical Physics, Department of Biomedical and Morphological Sciences, University of Verona, Verona, Italy. alberto.fenzi@univr.it
Alberto
A
Fenzi
Mirko
M
Bortolazzi
Pasquina
P
Marzola
D000818:Animals; D004195:Disease Models, Animal; D007501:Iron / Q000378:metabolism*; D008099:Liver / Q000378:metabolism; D008107:Liver Diseases / Q000175:diagnosis* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
D007501:Iron