[O-1-039] 0.025 mmol/kg and 0.050 mmol/kg gadoxetic acid for liver MRI: An Intra-individual comparison
Purpose: To quantitatively make intraindividual comparison of the performance of 0.025 mmol/kg and 0.05mmol/kg for gadoxetic acid-enhanced MR imaging.
Materials and Methods: Eleven healthy volunteers underwent liver MRI twice with 0.025 and 0.05 mmol/kg gadoxetic acid. MR spectroscopy and 3D gradient-echo T1-weighted images were obtained precontrast, and 3, 10 and 20 min post-injection to measure T1/T2 values, signal-to-noise ratio (SNR) of the liver and contrast-to-noise ratio (CNR) of the liver versus portal vein and muscle. During the dynamic phase, time-resolved 3D gradient-echo T1-weighted imaging with 2 s temporal resolution was used to monitor relative CNR (CNRrel) of the hepatic artery and portal vein versus liver. Paired t-tests were used to compare the measured values obtained using the two different doses.
Results: During the hepatobiliary phase, significantly shorter T1 values and higher SNRs of the liver (p ＜0.001), and higher liver-to-portal vein/-muscle CNR (p ＜0.002) were observed with 0.050 mmol/kg than 0.025 mmol/kg By doubling the dose, higher T1 shortening effect was obtained even at 10 min delay compared with the scan with a 0.025 mmol/kg at 20 min delay (p ＜0.001). The T2 values of the liver were not significantly different with a 0.025 mmol/kg (24ms) and 0.050 mmol/kg (23ms) at 20 min after injection. During the dynamic phase, peak CNRrel for hepatic artery and portal vein were significantly higher using 0.050 mmol/kg compared with 0.025 mmol/kg.
Conclusion: A dose of 0.050 mmol/kg gadoxetic acid leads to high SNR and CNR performance compared to 0.025mmol/kg. A 10 minute delay is quantitatively feasible for hepatobiliary phase when using 0.050 mmol/kg of gadoxetic acid.
Materials and Methods: Eleven healthy volunteers underwent liver MRI twice with 0.025 and 0.05 mmol/kg gadoxetic acid. MR spectroscopy and 3D gradient-echo T1-weighted images were obtained precontrast, and 3, 10 and 20 min post-injection to measure T1/T2 values, signal-to-noise ratio (SNR) of the liver and contrast-to-noise ratio (CNR) of the liver versus portal vein and muscle. During the dynamic phase, time-resolved 3D gradient-echo T1-weighted imaging with 2 s temporal resolution was used to monitor relative CNR (CNRrel) of the hepatic artery and portal vein versus liver. Paired t-tests were used to compare the measured values obtained using the two different doses.
Results: During the hepatobiliary phase, significantly shorter T1 values and higher SNRs of the liver (p ＜0.001), and higher liver-to-portal vein/-muscle CNR (p ＜0.002) were observed with 0.050 mmol/kg than 0.025 mmol/kg By doubling the dose, higher T1 shortening effect was obtained even at 10 min delay compared with the scan with a 0.025 mmol/kg at 20 min delay (p ＜0.001). The T2 values of the liver were not significantly different with a 0.025 mmol/kg (24ms) and 0.050 mmol/kg (23ms) at 20 min after injection. During the dynamic phase, peak CNRrel for hepatic artery and portal vein were significantly higher using 0.050 mmol/kg compared with 0.025 mmol/kg.
Conclusion: A dose of 0.050 mmol/kg gadoxetic acid leads to high SNR and CNR performance compared to 0.025mmol/kg. A 10 minute delay is quantitatively feasible for hepatobiliary phase when using 0.050 mmol/kg of gadoxetic acid.