Keywords:
Abdomen, MR, Experimental investigations, Metabolic disorders, Liver
Authors:
M. Juchems, H. Cario, A. Wunderlich; Ulm/DE
DOI:
10.1594/ecr2012/C-2248
Methods and Materials
198 patients (age: 2-88 years,
mean age 28,9 y) suspected for liver iron overload were examined by MRI to evaluate the amount of LIC.
All examinations were performed at 1.5 T.
Gradient echo sequences were acquired according to the protocol published by Alustizia et al [1] (GRE1),
a similar method proposed by Gandon et al [2] (GRE2) and a protocol designed to address higher LIC by Rose et al.
[3] (GRE3).
Furthermore,
examinations with spin echo (SE) were performed with a protocol proposed by St.
Pierre et al.
[4].
For evaluation of GRE data,
signal values were measured by manually drawing circular regions of interest (ROIs) in vessel-free parts of the liver and in the paraspinal muscles (Fig.
1).
Calculating the ratio of muscle reference value and liver signal,
LIC was estimated according to [1-3].
If GRE1 yielded an LIC value of more than 180 µmol/g,
GRE2 was used up to values of 300 µmol/g.
If GRE2 exceeded this limit,
GRE3 was used.
Spin echo data was analyzed using a more sophisticated method [ref.
3 and references cited there] based on calculation of T2 relaxation time.
For each patient,
LIC values were compared.
The SE methods has an upper limit of 769 mmol/kg liver dry tissue,
so patients with values of more than 750 µmol/g determined from SE data were excluded from analysis.
Correlation between all GRE methods vs.
SE was determined,
as well as
GRE1 in its coverage vs.
SE