TH-CD-207-05: Combined Effects of Gadolinium Contrast and Inversion Recovery Pulse On Quantitative ADC Measurements in the Liver.

PURPOSE: Performing diffusion weighted imaging (DWI) immediately after Gadolinium (Gd) contrast administration is considered to have insignificant impact on apparent diffusion coefficient (ADC) measurements in the liver. However, our observation contradicts those findings. The goal of this study was to evaluate the impact of Gd and inversion recovery (IR) pulse on ADC measurements in the liver.

METHODS: DWI data was acquired on a 1.5T MRI scanner using 8-channel body coil from four patients pre-, 10-min post-, and 20-min post contrast with a TI of 0 (no fat suppression) and 120 ms, respectively. Respiratory triggered spin-echo single-shot echo-planar sequence was used: TR/TE, 10000/75 ms; FOV, 400×400 mm; matrix, 128×128; slice thickness, 6 mm; NEX, 4; and b = 0, 50, 500, 1000 mm ((2)) /s with acquisition time ∼2 min. 0.1 mmol/kg gadoxetate disodium (EOVIST, Bayer HealthCare) was used as the contrast agent. ADC measurements were performed from three (two right lobe and one left lobe) non-overlapping regions of interest (∼700 mm ((2)) area).

RESULTS: For TI = 0, the mean ADC of 1.7, 1.6, 1.7 x10-(3) mm ((2)) /s was observed for pre-Gd, 10 min post-Gd and 20 min post-Gd, respectively. For TI = 120, the mean ADC of 1.7, 2.7, 2.6 x10 -(3) mm ((2)) /s was observed for pre-Gd, 10 min post-Gd and 20 min post-Gd, respectively. A 35% increase in the ADC measurements were recorded for the values obtained post-Gd with the TI of 120 ms (p-value = 0.00026).

CONCLUSION: Adding an IR pulse to post-Gd DWI acquisition changes the quantitative ADC measurements in the liver. The ADC values measured were significantly higher across all subjects when an IR pulse was added to the post-contrast DWI. When no IR pulse was used, the quantitative ADC measurements were found to be consistent in both the pre-and post-contrast DWI, showing less variability.