In vivo investigation of hepatic iron overload in rats using T2 maps: Quantification at high intensity field (4.7-T)

In vivo quantitation of hepatic Iron content is useful in diagnosis and sta ging of several iron related diseases. We used an experimental model of hep atic iron overload to determine the correlation between iron content and T2 relaxation time in rat liver. Experiments were carried out at 4.7T for hig h signal-to-noise ratio (SNR) using a spin-echo multiecho sequence with six echoes and minimum echo-time of 5.5 msec. The liver iron content was deter mined ex vivo by atomic absorption spectrophotometry (AAS). T2 maps were ca lculated in order to evaluate the space distribution of the iron content. W e found good linear correlation between the in vivo liver transversal relax ation rate and the iron content within the range explored (106-4538 mug Fe/ g liver wet wt.). T2 maps revealed that the decrease in T2 is not homogeneo us through the liver parenchyma. This finding represents a physiological li mitation to obtaining better correlation between T2 and iron content. (C) 2 001 Wiley-Liss, Inc.