Purpose: We evaluated the diagnostic performance of fat-suppressed 3D T1-weighted gradient-echo magnetic resonance imaging (MRI) sequences for the hepatobiliary phase of gadoxetic-acid-enhanced liver MRI between low and high flip angle (FA) at 3T.
Materials and methods: Forty-six patients with 62 HCCs were enrolled in this retrospective study from among 267 consecutive patients who underwent 3T MRI with low and high FA (10° and 25°) sequences at the hepatobiliary phase. A radiologist measured signal intensities and standard deviations (SD) of lesion, liver, and spleen and calculated signal-to-noise ratio, liver-spleen contrast, and liver-lesion contrast. Two reviewers assessed both image sequences using a five-point rating scale focusing on detecting hypointense lesions.
Results: The high FA sequence showed significantly higher liver-spleen and liver-lesion contrast compared with those of low FA (p < 0.05, p < 0.05, respectively). Per-lesion sensitivities of high FA were higher than those of low FA (p < 0.05, p < 0.05, respectively), and per-person sensitivities were elevated on high FA (p < 0.05 in a reviewer). There were statistically significant differences for detecting HCCs larger than 1 cm (p < 0.05, p < 0.05, respectively).
Conclusion: Increasing FA in T1-weighted hepatobiliary-phase liver MRI may help in detecting HCC at 3T.