A Comparative Study Of Real-time Elastography With Conventional Ultrasound In Differential Diagnosing Of Thyroid Nodules

Objective1. To investigate the clinical value of ultrasonic elastography(UE) in the diagnosis of thyroid nodules.2. To compare the application value and evaluate the advantages and shortages of UE and conventional ultrasonography in the diagnosis of thyroid nodules.MethodsSixty-eighty patients with totally 85 thyroid nodules who had undergone resection for thyroid nodules in the First Affiliated Hospital of Medical College, Shantou University were included in this study. 31 nodules were malignant and 54 were benign, all of which were confirmed by operation and pathology. No patients had received chemotherapy or radiotherapy before surgery and there was no evidence of any other malignancy. Real-time UE and conventional ultrasonography were used in the examination and all the patients were tested by SIEMENS Antares ultrasound system with a 5-13MHz transducer, which included the real-time elastographic technique.Size, shape, border, internal echo, calcification, halo and flow distribution of the nodules were analyzed by CUS and all the images were recorded exactly. Elasticity images were properly captured and stored, then classification of the nodules was done according to the standards. The comparisons of the diagnostic sensitivity, specificity, positive predictive value, and negative predictive value between UE and conventional ultrasound were analyzed ultimately.Results1. The characteristics of thyroid nodules on UEIn 85 nodules, 20 were classified as LevelⅠ, 15 were asⅡ, 20 wereⅢand the benign nodules were accounted for 90%, 86.7%, 75%, respectively. 21 nodules were classified as LevelⅣand 9 were as LevelⅤ, in which the malignant ones were accounted for 61.9% and 100%, respectively. Significant statistic difference was observed in the classification (P <0.05). 2. The diagnostic value of UE in the thyroid nodulesTaking≥LevelⅣas the criteria for malignancy, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of UE in the diagnosis for thyroid nodules was 71.0%, 85.2%, 73.3% and 83.6%, respectively.3. Comparison of real time UE and CUS in the diagnosis of thyroid nodulesThe sensitivity, specificity, PPV and NPV were 67.7%, 74.1%, 60.0% and 80.0% respectively if using the two-dimensional gray-scale ultrasound(2D) independently, and less sensitivity, specificity, PPV and NPV would be obtained when using color Doppler ultrasound(CDFI) solely, which were 61.3%, 74.1%, 57.6% and 76.9%, respectively. However, more sensitivity, specificity, PPV and NPV were observed when only using UE, which were 71.0%, 85.2%, 73.3% and 83.6%, respectively. More satisfied sensitivity, specificity, PPV and NPV could be achieved when combined 2D with CDFI, which were 74.2%, 87.0%, 76.7% and 85.5% and the most valuable parameters would be obtained when the combined use of these three diagnostic techniques was performed, which were 87.1%, 90.7%, 84.3% and 92.4%, respectively.Conclusion1. UE is effective in differentiating benign and malignant thyroid nodules and has a significant clinical value.2. The most satisfied sensitivity and specificity could be obtained when the combined use of UE, 2D and CDFI was performed and UE could provide more convincing evidences for clinical diagnosis. It is an additional process and development for conventional ultrasound.