Multiparameter estimation using multi-echo spoiled gradient echo with variable flip angles and multicontrast compressed sensing.

Abstract

To develop multiparameter mapping including T1 , R2*, and proton density fat fraction with a single breath-hold to evaluate liver disease and liver function. A 6-echo spoiled gradient-echo sequence with dual flip angles was used to acquire a 12-set MRI volume data set. To shorten the scan time, undersampling and multicontrast compressed-sensing reconstruction were used. The scan time was 18 seconds. R2* and proton density fat fraction mapping were achieved by using the iterative least-squares method. T1 mapping was estimated using driven equilibrium single-pulse observation of T1 . Quantitative values were validated by performing phantom and volunteer studies. Statistical analysis showed that the quantitative values measured using the proposed methods agreed with those measured using conventional methods. T1 values of water proton measured by the proposed method in phantom and volunteer studies were in good agreement with those by MRS. The results showed that accurate quantitative mapping of T1 , R2*, and proton density fat fraction with a single breath-hold was achieved using our approach.