Diffusion-weighted magnetic resonance imaging for the detection of thyroid cancer

Nodular thyroid disease possesses the potential to harbor malignancy. Our aim was to evaluate the significance of cervical diffusion-weighted magnetic resonance imaging (DW-MRI) for the detection of malignant thyroid nodules.

Sixty-five thyroid nodules from 58 patients who had undergone surgery were evaluated. Preoperative parameters, demographic data, ultrasound findings, fine-needle aspiration biopsy results and apparent diffusion coefficient (ADC) values of the nodules at DW-MRI were compared with the results from postoperative pathology examinations.

The "benign group" included 50 (76.9%) nodules, while 15 (23.1%) nodules constituted the "malignancy group". Minimum, maximum and mean ADC values of the nodules were significantly lower in the malignancy group (p < 0.05). The best cutoff value for the mean ADC value was 1.33 × 10-3 mm2/s, with a sensitivity of 66.67%, a specifity of 89.13%, a positive predictive value of 53.63% and a negative predictive value of 89.13%. A mean ADC value equal to or lower than 1.33 × 10-3 mm2/s was associated with 9 times higher risk of malignancy (odds ratio: 9.111, 95% confidence interval: 2.49-33.21).

The ADC value detected by cervical DW-MRI can be considered a predictive parameter for the detection of thyroid cancer.