ABSTRACT
Background: US is widely used in the assessment of the thyroid gland. Thyroid nodules may be benign or malignant. This study aimed to assess the great role of US, DW-MRI and ADC values in assessment of thyroid nodules and to reduce cost-effectiveness by decreasing number of unnecessary FNAC. Methods: Sixty-two patients with seventy-three thyroid nodules were included in a prospective study (seven males and fifty-five females). Sixty patients were new cases of thyroid nodules and two cases were recurrent cases post total thyroidectomy. Thyroid ultrasound was done to all patients. The nodules were classified into TIRADS categories. According to TIRADS, they were classified into groups A & B. The patients in group B performed DW-MRI examination. Results: Six nodules out of seventy-three were malignant. Malignant nodules were two in TIRADS 3, one in TIRADS 4b, two in TIRADS 5 and one in recurrent thyroid nodules. The major US features seen associated with malignancy were microcalcifications, hypoechoic echo pattern & irregular borders. Twelve patients with sixteen nodules performed DW-MRI and ADC value measurement. Eleven nodules showed free diffusion with higher ADC values and five nodules showed restricted diffusion with lower ADC values. On comparison with histopathology, four nodules with restricted diffusion & lower ADC values were proven to be malignant. So DW-MRI has high sensitivity (91.7%) and specificity (100%) in differentiating benign and malignant thyroid nodules. Conclusion: Combining US features, DW-MRI and ADC values could improve the diagnostic performance of US and MRI for malignant thyroid nodules.