Contrast-enhanced ultrasonography of nasopharyngeal carcinoma: enhancement patterns and quantitative parameters.

OBJECTIVE

The aim of this study was to investigate the characteristics of nasopharyngeal carcinoma (NPC) using contrast-enhanced ultrasonography (CEUS), including the enhancement patterns and the quantitative parameters.

METHODS

Having been scanned using conventional ultrasonography (US) and CEUS, every case was confirmed to be NPC under endoscopic biopsy, and no case received any anti-tumor treatment before CEUS examinations. Tumor/node/metastasis stages were determined in accordance with 2002 AJCC 6th edition. Contrast enhancement patterns and quantitative parameters were observed.

RESULTS

CEUS imaging of NPC showed that the tumor signal intensity enhanced early, rapidly, and remarkably, and decreased slowly later. The patterns of enhancement included spot/linear enhancement, peripheral enhancement, and mass enhancement, and two types of time intensity curves of NPC included type I and type II. There was a significant difference between peak intensity (PI) and T stage (P<0.05), whereas time-to-peak (TP) and slope did not show significant differences with T stage (P>0.05).

CONCLUSION

CEUS is feasible to be applied to the nasopharynx region. The use of CEUS makes it possible to observe vascular permeability of NPC. Our results suggest that the quantitative parameter PI of nasopharyngeal carcinoma is significantly different from T stages. Thus, PI may serve as a potential noninvasive radiological prognostic indicator for NPC.