Dynamic Gd-enhanced MR imaging of hepatic hemangioma: is high temporal resolution requisite for characterization?

ABSTRACT

We assessed the value of high temporal resolution in the dynamic characterization of hepatic hemangioma with use of magnetization-prepared gradient-echo (MP-GRE) imaging. Single-level inversion recovery incremental flip angle MP-GRE images were obtained in 26 patients with 34 hemangiomas before and at a repetition rate of 30 images/min after injection of Gd-DTPA without breath-holding. Enhancement patterns and temporal changes thereof were analyzed. Hemangiomas were categorized as small ( < 2.0 cm), medium (2.0-5.0 cm), and large ( > 5 cm) lesions. Classic early peripheral nodular enhancement (PNE) with progressive hyperintense fill-in was observed in 31 lesions (91%). Two of 10 small and 1 of 20 medium lesions showed complete fill-in within 10 s, and three small and one medium lesions within 45 s after the onset of PNE. In no cases of hemangioma was immediate homogenous hyperintensity observed without preceding PNE. In conclusion, temporal resolution of less than 10 s is a prerequisite for confident dynamic characterization of some hemangiomas, predominantly small hemangiomas.