Simultaneous acquisition of high-contrast and quantitative liver T1 images using 3D phase-sensitive inversion recovery: a feasibility study.

Background Tumor-to-liver contrast is low in images of chronically diseased livers because gadolinium-based hepatocyte-specific contrast agents (Gd-EOB-DTPA) accumulate less to hepatocytes. Purpose To determine whether phase-sensitive inversion recovery (PSIR) could improve the T1 contrasts of Gd-based contrast agents and liver parenchyma and simultaneously provide accurate T1 values for abdominal organs. Material and Methods The image contrasts of phantoms with different Gd concentrations that were obtained using PSIR were compared to conventional turbo field echo (TFE) results. T1 value was estimated using PSIR by performing iterations to investigate the two IR magnetization evolutions. The estimated T1 values were validated using IR-spin echo (IR-SE) and Look-Locker (L-L) sequences. In an in vivo study, the liver-to-spleen and liver-to-muscle contrasts of the PSIR and TFE images of seven volunteers were compared, as were the T1 values of liver parenchyma, spleen, and muscle obtained using PSIR and L-L sequences. Results The PSIR images showed T1 contrasts higher than those in the TFE results. The PSIR and IR-SE T1 values were linearly correlated. Additionally, the R1 estimated using PSIR were correlated with those measured using IR-SE and L-L. In the in vivo study, the liver-to-spleen and liver-to-muscle contrasts of PSIR were significantly higher than those obtained using TFE. T1 values of abdominal organs obtained using PSIR and L-L were clearly correlated. Conclusion PSIR may be capable of improving liver image T1 contrasts when Gd-based contrast agents are employed and simultaneously yielding accurate T1 values of abdominal organs.