Manuela Franca MD, Presenter: Nothing to Disclose

Angel Alberich Bayarri, Abstract Co-Author: Nothing to Disclose

Luis Marti-Bonmati MD, PhD, Abstract Co-Author: Nothing to Disclose

Joao Andre Oliveira, Abstract Co-Author: Nothing to Disclose

Francisca Emanuel Costa MD, Abstract Co-Author: Nothing to Disclose

Eduardo Ribeiro, Abstract Co-Author: Nothing to Disclose

Jose Ramon Vizcaino Vazquez, Abstract Co-Author: Nothing to Disclose

Graca Porto, Abstract Co-Author: Nothing to Disclose

Helena Pessegueiro Miranda, Abstract Co-Author: Nothing to Disclose

Liver biopsy is the standard technique to evaluate diffuse liver disorders. However, it is invasive, may have complications and has sampling bias. The purpose of this study is to validate an MR protocol that allows simultaneous measurement of fat and iron within the liver in a single breath-hold.

In this prospective study, consecutive patients with diverse diffuse liver disorders and clinically indicated liver biopsy were recruited. To estimate proton-density fat fraction (PDFF) and iron R2*, a 3.0T MR examination using a single breath-hold ME-CSh-GRE sequence (TR/TE=10/0.99, 1.69, 2.39, 3.09, 3.79, 4.49, 5.19, 5.89, 6.59, 7.29, 7.99, 8.69ms) was used. Quantification was performed with dedicated software (with magnitude and phase reconstruction, T1 bias and T2* correction, and multipeak fat spectral modeling) selecting a ROI within the biopsied liver segment. Liver biopsy was used as gold standard for steatosis (0-3) and iron deposits (0-4) grading. Relationship between MR measurements and pathological grading was statistically assessed by non-parametric Kendall’s tau-b. Differences of the calculated parameters between histopathological grades were assessed by ANOVA tests.

A total of 104 patients were enrolled. Regarding histological steatosis grading, patients distribution was (grade/n) 0/78; 1/14; 2/ 6; 3/6. Analogously, histological iron grading distribution was 0/54; 1/28; 2/12; 3/5; 4/5. There were 14 patients with both iron and fat deposits. PDFF mean, median, 25 and 75-percentile showed significant differences between steatosis grade (p<0.001), with a high significant correlation with histological results (τ=0.388, τ=0.475; τ=0.550; τ=0.262; all p<0.001). R2* measurements were also significantly different between iron histological grade (p<0.001), with high significant positive correlations for mean (τ=0.389), median (τ=0.383), 25p (τ=0.394) and 75p (τ=0.386) R2* vs. histology grade (p<0.001).

Our results demonstrate an excellent relationship between ME-CSh-GRE MR derived PDFF and iron R2* quantifications against liver biopsy. This sequence allows to accurately measuring fat and iron in different diffuse liver disorders, even if they coexist.

This ME-CSh-GRE MR sequence can be used to estimate fat and iron as a fast, non-invasive and quantitative liver imaging biomarkers.

Franca, M, Alberich Bayarri, A, Marti-Bonmati, L, Oliveira, J, Costa, F, Ribeiro, E, Vizcaino Vazquez, J, Porto, G, Pessegueiro Miranda, H, Quantification of Liver Steatosis and Iron Overload in Diffuse Liver Disorders: Histological Validation of a 3.0 T MRI Multi-Echo Chemical Shift Gradient Echo (ME-CSh-GRE) Single Breath-hold Sequence.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14009657.html