T1-refBlochi: High resolution 3D post-contrast T1 myocardial mapping based on a single 3D late gadolinium enhancement volume,Bloch equations,and a reference T1

Background: high resolution 3d t1 mapping is important for assessment of diffuse myocardial fibrosis in left atrium or other thin-walled structures. in this work,we investigated a fast single-ti 3d high resolution t1 mapping method that directly transforms a 3d late gadolinium enhancement (lge) volume to a 3d t1 map. methods: the proposed method,t1-refblochi,is based on bloch equation modeling of the lge signal,a single-point calibration,and assumptions that proton density and t2∗are relatively uniform in the heart. several sources of error of this method were analyzed mathematically and with simulations. imaging was performed in phantoms,eight swine and five patients,comparing t1-refblochi to a standard spin-echo t1 mapping,3d multi-ti t1 mapping,and 2d shmolli,respectively. results: the method has a good accuracy and adequate precision,even considering various sources of error. in phantoms,over a range of protocols,heart-rates and t1 s,the bias ±1sd was -3 ms ± 9 ms. the porcine studies showed excellent agreement between t1-refblochi and the multi-ti method (bias ±1sd = -6 ± 22 ms). the proton density and t2∗weightings yielded ratios for scar/blood of 0.94 ± 0.01 and for myocardium/blood of 1.03 ± 0.02 in the eight swine,confirming that sufficient uniformity of proton density and t2∗weightings exists among heterogeneous tissues of the heart. in the patients,the mean t1 bias ±1sd in myocardium and blood between t1-refblochi and shmolli was -9 ms ± 21 ms. conclusion: t1-refblochi provides a fast single-ti high resolution 3d t1 map of the heart with good accuracy and adequate precision. © 2017 the author(s).