PURPOSE: To investigate optimal delay time of hepatic arterial phase in Gadoxetate-enhanced MR for detecting hypervascular hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Forty-five patients with 85 hypervascular HCCs and 9 patients with 16 hypervascular HCCs underwent Gadoxetate- and Gd-DTPA-enhanced MR at 1.5 Tesla (T) system, respectively. All HCCs were analyzed 10-38 s after injection using a time-resolved dynamic MR sequence with keyhole data sampling. Seven sequential phase images (1 phase = 4 s) were obtained during a single breath hold of 28 s. Time-intensity curves of the abdominal aorta, liver parenchyma, and HCC were obtained, then aortic contrast arrival time, time of peak HCC enhancement, duration time of HCC and aortic enhancement, and time delay from aortic contrast arrival to peak enhancement of HCC were measured. RESULTS: Aortic contrast arrival time was 15.1 ± 2.9 s, time of peak HCC enhancement 29.9 ± 4.6 s, duration time of HCC enhancement 17.4 ± 6.4 s postinjection of Gadoxetate. Duration of aortic enhancement (23.6 ± 3.5 s) of Gadoxetate-enhanced MR was significantly less than that of Gd-DTPA-enhanced MR (26.3 ± 2.8 s) (P < 0.0059). CONCLUSION: Peak enhancement time of HCC on Gadoxetate-enhanced MR imaging occurred at 14.6 ± 4.6 s after aortic contrast arrival.
PURPOSE: To investigate optimal delay time of hepatic arterial phase in Gadoxetate-enhanced MR for detecting hypervascular hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Forty-five patients with 85 hypervascular HCCs and 9 patients with 16 hypervascular HCCs underwent Gadoxetate- and Gd-DTPA-enhanced MR at 1.5 Tesla (T) system, respectively. All HCCs were analyzed 10-38 s after injection using a time-resolved dynamic MR sequence with keyhole data sampling. Seven sequential phase images (1 phase = 4 s) were obtained during a single breath hold of 28 s. Time-intensity curves of the abdominal aorta, liver parenchyma, and HCC were obtained, then aortic contrast arrival time, time of peak HCC enhancement, duration time of HCC and aortic enhancement, and time delay from aortic contrast arrival to peak enhancement of HCC were measured. RESULTS: Aortic contrast arrival time was 15.1 ± 2.9 s, time of peak HCC enhancement 29.9 ± 4.6 s, duration time of HCC enhancement 17.4 ± 6.4 s postinjection of Gadoxetate. Duration of aortic enhancement (23.6 ± 3.5 s) of Gadoxetate-enhanced MR was significantly less than that of Gd-DTPA-enhanced MR (26.3 ± 2.8 s) (P < 0.0059). CONCLUSION: Peak enhancement time of HCC on Gadoxetate-enhanced MR imaging occurred at 14.6 ± 4.6 s after aortic contrast arrival.