하시모토 갑상선염의 경부 전산화단층촬영에서 갑상선의 3차원 용적과히스토그램에 대한 정량적 분석

Abstract

Purpose: To analyze three-dimensional (3D) volume and histogram of thyroid gland on neck computed tomography (CT) for patients with Hashimoto’s thyroiditis. Materials and Methods: A total of 121 subjects who underwent neck CT between March 2013 and February 2014 were included in this study. These subjects were divided into the following two groups: 1) control group (n = 76); 2) Hashimoto’s thyroiditis group (n = 45). Non-enhanced and contrast-enhanced CT images were obtained. On contrast-enhanced images, the 3D volume of thyroid gland was semi-automatically calculated. On CT histogram, attenuation number, mean, median, standard deviation (SD), and coefficient of variation (CV) of thyroid gland were calculated. These values were compared between the two groups. Results: Total 3D volume of thyroid gland was 14.9 ± 4.8 cm3 in the control group, which was significantly (p = 0.002) lower than that (19.2 ± 8 cm3) in the Hashimoto’s thyroiditis group. On CT histogram, the mean, median, SD, and CV of thyroid gland on non-enhanced images were 95.8, 99.3, 21.7, and 0.226, respectively, in the control group and 72.2, 72.6, 19.6, and 0.28 in the Hashimoto’s thyroiditis group (p < 0.05). Histogram parameters on contrast-enhanced images were not significantly (p > 0.05) different. Median at cut-off value of 83 revealed the largest Az value (Az: 0.905; 95% confidence interval: 0.837–0.951; sensitivity: 84.4%; specificity: 85.5%). Conclusion: The Hashimoto’s thyroiditis group had larger volume but lower CT attenuation number with more prominent parenchymal heterogeneity of thyroid gland than the control group.