Investigation of Acoustic Structure Quantification in the Diagnosis of Thyroiditis

Abstract

OBJECTIVE. The objective of this study was to evaluate the ability of acoustic structure quantification (ASQ) to diagnose thyroiditis. MATERIALS AND METHODS. The echogenicity of 439 thyroid lobes, as determined using ASQ, was quantified and analyzed retrospectively. Thyroiditis was categorized into five subgroups. The results were presented in a modified chi-square histogram as the mode, average, ratio, blue mode, and blue average. We determined the cutoff values of ASQ from ROC analysis to detect and differentiate thyroiditis from a normal thyroid gland. We obtained data on the sensitivity and specificity of the cutoff values to distinguish between euthyroid patients with thyroiditis and patients with a normal thyroid gland. RESULTS. The mean ASQ values for patients with thyroiditis were statistically significantly greater than those for patients with a normal thyroid gland (p < 0.001). The AUCs were as follows: 0.93 for the ratio, 0.91 for the average, 0.90 for the blue average, 0.87 for the mode, and 0.87 for the blue mode. For the diagnosis of thyroiditis, the cutoff values were greater than 0.27 for the ratio, greater than 116.7 for the mean, and greater than 130.7 for the blue average. The sensitivities and specificities were as follows: 84.0% and 96.6% for the ratio, 85.3% and 83.0%, for the average, and 79.1% and 93.2% for the blue average, respectively. The ASQ parameters were successful in distinguishing patients with thyroiditis from patients with a normal thyroid gland, with likelihood ratios of 24.7 for the ratio, 5.0 for the average, and 11.6 for the blue average. With the use of the aforementioned cutoff values, the sensitivities and specificities for distinguishing between patients with thyroiditis and euthyroid patients without thyroiditis were 77.05% and 94.92% for the ratio, 85.25% and 82.20% for the average, and 77.05% and 92.37% for the blue average, respectively. CONCLUSION. ASQ can provide objective and quantitative analysis of thyroid echogenicity. ASQ parameters were successful in distinguishing between patients with thyroiditis and individuals without thyroiditis, with likelihood ratios of 24.7 for the ratio, 5.0 for the average, and 11.6 for the blue average.