THE ROLE OF DIFFUSION WEIGHTED MRI STUDY AND ITS QUANTITATIVE PARAMETER, APPARENT DIFFUSION COEFFICIENT VALUE, TO DIFFERENTIATE MALIGNANT FROM BENIGN THYROID NODULES

Abstract

Thyroid nodule evaluation is usually done using ultrasound examination and a
fine needle aspiration cytology/biopsy. The aim of this study was to evaluate the role
of diffusion weighted imaging to differentiate benign from malignant thyroid
nodules. Fifty five patients, 3 males (5.5%) and 52 females (49.5%) (17–66 years,
mean age 44.4 years) with thyroid nodules were included in the study. Routine MRI of
neck and diffusion-weighted MR imaging was performed using b-values 1000.
Apparent diffusion coefficient (ADC) values were done for every case.
Histopathological results of the thyroidectomy samples were obtained. Comparison
of apparent diffusion coefficient values of thyroid nodules with the histopathology
was done.The pathology results showed that there were 44 (80%) and 11 (20%)
benign and malignant thyroid nodules respectively. The mean maximum diameter of
benign and malignant thyroid nodules were 3.5 ±1.3 cm and 2.7± 0.9cm respectively,
The mean ADC for being and malignant nodules were 2.10 ±0.49 x10-3 and 1.10
±0.15x 10-3 respectively. ADC values for benign and malignant thyroid nodules which
were significant (p< 0.001).