Differentiation of thyroid nodules using Acoustic Radiation Force Impulse Imaging

M. Friedrich-Rust; N. Dauth; C. Berner; G. Meyer; K. Holzer; F. Gruenwald; L. Voelkl; E. Herrmann; H. Schroeter; S. Zeuzem; J. Bojunga

Objective: Acoustic Radiation Force Impulse (ARFI)-Imaging is a novel ultrasound-based elastography method enabling quantitative measurement of tissue stiffness. The aim of the present study was to evaluate ARFI for the differentiation of thyroid nodules and to compare it with the well known qualitative Realtime-Elastography (RTE)

Materials and Methods: ARFI-imaging involves the mechanical excitation of tissue using short-duration acoustic pulses to generate localized displacements in tissue. The displacements result in shear-wave propagation which is tracked using ultrasonic, correlation-based methods and recorded in m/s. Inclusion criteria were: nodules ≧5 mm, non-functioning or hypo-functioning on radionuclide scanning, and cytological/histological assessment. All patients received conventional ultrasound, real-time elastography and ARFI-imaging.

Results: ###129 nodules in 113 patients were available for analysis. One-hundred-fourteen nodules were benign on cytology/histology, and 15 nodules were malignant (8xpapillary carcinoma, 4xfollicular carcinoma, 3xmedullary carcinoma). The median velocity of ARFI-imaging in the healthy nodule-free thyroid gland, as well as in benign and malignant thyroid nodules was 1.74m/s (range:0.89–3.33m/s), 1.91m/s (range:0.72–3.73m/s), and 3.63m/s (range:0.80–6.83m/s), respectively. The velocity in malignant nodules was significant higher than in benign nodules (P=0.001). The negative predictive value of ARFI for the diagnosis of malignant thyroid nodules was 94% using a cut-off of 3.0m/s. This was comparable to RTE with a NPV of 95%.

Conclusions: ARFI can be performed in the thyroid tissue with reliable results. This novel quantitative elastography-method can be performed with negative predictive value in the diagnostic work-up of thyroid nodules.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector

Endocrine Abstracts

P1814