Initial experience of 3 tesla apparent diffusion coefficient values in differentiating benign and malignant thyroid nodules

Abstract

To evaluate the role of diffusion-weighted magnetic resonance imaging (DWMRI) in differentiating benign and malignant thyroid nodules using a 3 Tesla (T) MRI scanner. Twenty-eight nodules in 25 patients and 14 healthy control cases were included in the study. DWMRI was acquired with 6 b values with a 3T MRI scanner. The apparent diffusion coefficient (ADC) values of the nodules were calculated from reconstructed ADC map images and were compared with the final histopathological diagnoses. The mean ADC value of the benign nodules was 1548 ± 353.4 (×10(-6) mm(2) /s), and the mean ADC of the malignant nodules was 814 ± 177.12 (×10(-6) mm(2) /s). The normal thyroid tissue had a mean ADC value of 1323.43 ± 210.35 × 10(-6) mm(2) /s (958-1689 × 10(-6) mm(2) /s) in the healthy control group. The ADC values were significantly different among the three groups (P = 0.001). An ADC value of 905 × 10(-6) mm(2) /s was determined to be the cutoff value for differentiating benign and malignant nodules, with 90% (55.5-98.3) sensitivity and 100% (81.3-100.0) specificity. This study suggests that the ADC values of nodules measured with a 3T MRI scanner could help in differentiating benign thyroid nodules from malignant nodules.