The value of ultrasound elastography-guided fine-needle aspiration biopsy of thyroid nodules in reducing nondiagnostic results.

Abstract

Fine-needle aspiration biopsy (FNAB) is an important tool for diagnosing thyroid nodules; however, nondiagnostic results are a problem with FNAB. We evaluated the optimal targeting area of thyroid nodules for FNAB by using ultrasound elastography (USE) to reduce nondiagnostic results. Between December 2008 and November 2010, 96 consecutive prospective subjects scheduled to undergo FNAB were included in the study. Initially, the dominant nodule was evaluated with ultrasound, after which USE was performed. FNABs were performed from both the red (hard foci) and the green (soft foci) color-coded areas using the same technique according to the USE maps. The cellularity of all the specimens was evaluated cytopathologically. Nondiagnostic results from the red and green color-coded areas were compared by Chi-square test. In the red color-coded regions on USE images, the diagnostic rate was 76.0% and the nondiagnostic rate was 24.0%. In the green color-coded regions on USE images, the diagnostic rate was 53.1% and the nondiagnostic rate was 46.9%. Seven nodules were malignant and 89 were benign. Nondiagnostic results were significantly fewer in red color-coded regions (P=0.0001). USE can help to enhance the cellularity of biopsy of thyroid nodules to reduce the nondiagnostic results if the red color-coded (less elastic or hard) areas are preferred.