The value of using iodine maps in distinguishing the benign and malignant thyroid nodule with dual-source CT by dual energy

Objective To investigate the clinical application of iodine-enhanced image of dual-source computed tomography(DSCT)in distinguishing benign and malignant thyroid nodules. Methods Thirty patients with thyroid nodules underwent DSCT imaging with dual-source computed tomography. All thyroid nodules were confirmed by operation or biopsy. Iodine concentration in the thyroid nodule and normal thyroid tissue were calculated and not enhanced. A receiver operator characteristic curve in SPSS software was utilized to select critical value of optimum sensitivity and specificity. The data were retrospectively analyzed. Results There were 30 patients with 40 thyroid nodules(17 malignant nodules, 23 benign nodules). The range of iodine concentration in malignant nodules was -2.4-0.9 mg/ml(median -0.5 mg/ml), and that in normal thyroid tissue was -0.9-2.2 mg/ml(median 0.7 mg/ml). The range of iodine concentration in benign nodules was 1.5-4.4 mg/ml(median 2.4 mg/ml), and that in normal thyroid tissue was 1.5-4.3 mg/ml(median 2.6 mg/ml). Among them, the iodine concentration in the solid part of benign nodules was significantly higher than that in malignant nodules, the difference was statistically significant(Z=-3.23, P=0.21). When critical value was 0.15 mg/ml, sensitivity was 82.40%, specificity was 81.00%. Conclusion Iodine-enhanced images with DSCT in non-enhanced weighted images may be an implement tool for differential diagnosis of benign and malignant nodules of the thyroid gland. (Chin J Endocrinol Metab, 2015, 31: 333-336) Key words: Thyroid nodule; Tomography, X-ray computed; Iodine image