The Quantitative MRI Study On Microangiopathy And Fat Fraction Of Bone Marrow In Type 2 Diabetic Mellitus

Part ? Effect of gadolinium on vertebral fat fraction content using IDEAL-IQ techniqueObjective:This study evaluates the robustness of a magnetic resonance(MR)fat quantifcation method to changes in R2*caused by an intravenous infusion of gadolinium.Methods:The R2*and fat fraction content(FF)were measured in vertebral marrow in eight New Zealand white rabbits using an investigational sequence(IDEAL IQ)provided by the MR scanner vendor.Measurements were made once before and twice after Gd-BOPTA infusion(5min,30min).Then HE stain was performed for calculating vertebral fat content(FCHIS),Prussian blue stain was performed for showing iron in vertebral.Result:vertebral marrow FF measurements revealed no significant systematic bias between the three measurements(P>0.05 for all).Good agreement(95%confdence interval)of FF measurements were demonstrated between FF0min and FF5min(0.90,1.10)and FF0min and FF30min(0.94,1.07).A signifcant positive correlation is found between FF0min and FCHIS(r=0.813,P<0.05).R2*increased after administration of gadolinium.Conclusions:Although under the impact of an increased R2*in vertebral marrow post-contrast,the investigational sequence can still obtain accurate and stable fat fraction content.the IDEAL IQ method of fat quantifcation is robust to changes in R2*.Part ? The quantitative MRI study on microangiopathy and fat fraction of bone marrow in newly-diagnosed patients with type 2 diabetic mellitusObjective:To explore the effect of type 2 diabetes on bone marrow fat contnent(BMF)and marrow blood flow,as well as the association of the bone marrow fat contnent and marrow perfusion in newly-diagnosed patients with type 2 diabetes mellitus(T2DM).Materials:Twenty four T2DM patients newly diagnosed by clinical assessments(11 male,13 female,age:50?70 years)and 26 healthy non-diabetic subjects(16 male,10 female,age:50?70 years)were enrolled in this study,consent forms were obtained.All the participants underwent MRI scans on a 3.0T whole body scanner.The scans included iterative decomposition of water and fat with echo asymmetry and least-squares estimation(IDEAL-IQ)and Dynamic Contrast Enhance Magnetic Resonance Imaging(DCE-MRI).Final BMF values were obtained by averaging values from the three raw consecutive maps in the center;DCE-MRI parameters(Ktrans,Kep,Ve)were derived using the Tofts pharmacokinetic model[2]in the Omni Kinetics software.The difference of BMF,Ktrans,Kep,Ve between T2DM patients and the healthy individuals were analyzed using two independent sample t test.Bivariate correlation coefficients were used to evaluate the relationship between BMF and Ktrans,Kep,Ve of T2DM patients.Result:The BMF and the parameters of perfusion constant(Ktrans),efflux rate constant(Kep),extravascular extracellular space(Ve)of lumbar vertebra all showed significant difference between T2DM patients and the healthy individuals.Correlation analysis showed that there was a negative correlation between the BMF and Ktrans(r=-0.441,P =0.02),but no correlation was observed with Kep and Ve(P>0.05).Conclusions:Type 2 diabetes has an effect on increasing bone marrow fat content and alters marrow blood flow and perfusion characteristics,which can aggravate each other during the progression of T2DM.