Haoran Sun, Presenter: Nothing to Disclose

Bing Liu, Abstract Co-Author: Nothing to Disclose

To evaluate the role of diffusion-weighted imaging (DWI) apparent diffusion coefficient (ADC) values in differentiation between malignant and benign thyroid nodules on 3.0T

From Jul 2010 to Feb 2011, seventeen patients with twenty-seven benign thyroid nodules (sized 0.6~4.1cm, mean diameter 2.4cm) and eleven patients with thirteen thyroid malignancies (sized 0.4~4.3cm, mean diameter 2.0cm) and twenty healthy volunteers were included in the study, informed consent was obtained. All the patients underwent MR examination one day to seven days prior to operation. Propeller DWI of b value 0 and 1000 s/mm2 was obtained with 3.0T MR scanner in addition to conventional sequences. The ADC maps were reconstructed; the averaged ADC values from round region of interest drawn on the solitary regions of nodules according to T2 weighted images were calculated. The overall predictive power of ADC was determined by receiver operating characteristic (ROC) analysis.

The ADC values of the three groups of benign and malignant nodules in patients and normal thyroid tissues were significantly different (oneway ANOVA, P =0.000).The mean ADC values of benign group (mean 2.43±0.54×10-3mm2/s, ranged1.41~3.62×10-3 mm2  /s) were significant higher ( t-test, P =0.000) than that of malignant group (mean 1.49±0.35×10-3 mm2 /s, ranged 0.60~1.95×10-3mm2/s). Normal thyroid tissues had mean ADC values of 1.84±1.99×10-3 mm 2/s (ranged 1.37~2.28×10 -3mm 2/s). The area under curve for ADC values to predict malignant thyroid nodules was 0.92 (95% confidence interval, 0.84–1.01; p < 0.001), the cutoff value of 2.04×10 -3 mm2 /s to differentiate thyroid malignancies reached a sensitivity of 85.2% and specificity of 100%.

The ADC mapping provides promising results in distinguishing benign from malignant thyroid nodules.

DWI is useful in distinguishing malignant from benign thyroid nodules.

Sun, H, Liu, B, Differentiation of Malignant and Benign Thyroid Nodules by Apparent Diffusion Coefficient Values on 3.0 T.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11034629.html