The frequency and clinical significance of the halo sign in focal nodular hyperplasia of the liver.

Objective: The purpose of this study was to investigate the frequency of the halo sign in focal nodular hyperplasia (FNH) of the liver and its clinical significance.

Methods: Archives of 19 patients (6 men, mean age 35 years +/- 11, range 22-53 years and 13 women, mean age 39 years +/- 15, range 17-66 years) diagnosed from April 2005 through March 2012 with FNH were reviewed. All images were analyzed by three readers in a panel in order to depict the characteristics of the liver lesions and established in consensus a diagnosis. The halo appearance of lesions was focused upon.

Result: The halo sign was found in 6 FNHs (31.6%, 6/19). The mean size of the FNHs was 34.2 mm +/- 7.2 (range 23-47 mm). Characteristics of FNH appear were various in gray-scale ultrasound and color Doppler flow imaging, CT and MRI, and combined use of different modalities may enable diagnosis definitely. All patients with FNH reviewed were consistent with previous diagnoses.

Conclusions: The halo sign was found in a high number of patients in this study, which implies that the halo sign may be not rare in FNH on sonography, and absence and presence of the halo sign may not help identifying FNH.