Simultaneous acquisition of high-contrast and quantitative liver T 1 images using 3D phase-sensitive inversion recovery: a feasibility study

Abstract

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.