Hepatocellular carcinoma with nodule-in-nodule appearance: demonstration by contrast-enhanced coded phase inversion harmonic imaging.

OBJECTIVE: A nodule-in-nodule hemodynamic pattern, namely a vascular spot in a hypovascular nodule, is specific for the diagnosis of early-stage hepatocellular carcinoma (HCC). The purpose of this study was to assess whether this unique hemodynamic pattern can be detected by contrast-enhanced coded phase inversion harmonic imaging (PIHI).

METHODS: 159 consecutive patients with HCC who underwent contrast-enhanced coded PIHI were retrospectively reviewed. Cases with nodule-in-nodule patterns were selected, and findings were compared with those on computed tomography (CT) angiography (CTA) and intraarterial contrast-enhanced ultrasonography (US angiography).

RESULTS: Contrast-enhanced coded PIHI successfully displayed the nodule-in-nodule hemodynamic pattern in two cases of histologically proven HCC and the hemodynamic transition in one of the two cases, which corresponded well with findings on CTA and US angiography.

CONCLUSIONS: Contrast-enhanced coded PIHI can demonstrate the special nodule-in-nodule hemodynamic pattern. It is useful in the diagnosis and follow-up of early-stage HCC or suspected nodules because of its noninvasiveness and easy performance.