Objective: We assessed the value of dynamic sequential three-dimensional Fourier transformation (3DFT) MRI in differentiating various types of small liver tumors.
Materials and methods: Forty-seven patients with 65 liver masses < 3 cm in size (42 hepatocellular carcinomas, 11 hemangiomas, 12 metastatic tumors) were studied by 3DFT fast imaging with steady-state precession (FISP) MRI [TR(ms)/TE(ms)/flip angle (degree): 20/8/30]. The slab thickness was 21-35 mm, and there were seven partitions. The 3DFT-FISP MR images were obtained immediately after 0.1 mmol/kg of gadopentetate dimeglumine was administered intravenously over 2-3 s (early phase), 60 s after (late phase I), and 120 s after (late phase II).
Results: Eighty-six percent of small hepatocellular carcinomas showed hyperintense enhancement relative to the surrounding liver parenchyma and iso- or hypointense enhancement with or without capsular enhancement in the late phase. Eighty-two percent of small hemangiomas showed peripheral globular enhancement in the early phase and total hyperintense or peripheral enhancement in the late phases. Ninety-two percent of the small metastatic liver tumors showed doughnut-like ring enhancement in the early phase.
Conclusion: By dynamic 3DFT-FISP MRI, we were able to accurately evaluate the hemodynamics and morphological findings of each type of small liver tumor.