Development and application of magnetic resonance elastography of the normal and pathological thyroid gland in vivo

Purpose: To noninvasively assess the shear stiffness of the thyroid gland in vivo in order to determine whether magnetic resonance elastography (MRE) might hold clinical utility in the diagnosis of thyroid disease. Materials and Methods: Quantitative parametric images of thyroid stiffness in normal volunteers and patients were produced and quantitative stiffness values measured. Average gland stiffness was determined by region of interest analysis of the parametric images. This technique was used to assess stiffness of the thyroid in normal individuals (n = 12), patients with Hashimoto's thyroiditis (HT; n = 5), and patients with a solitary benign (n = 8) or malignant (n = 2) thyroid nodule. Results: Mean shear modulus of normal thyroid glands was 1.9 ± 0.6 kPa at 100 Hz and 1.3 ± 0.5 kPa at 80 Hz, while that of HT glands was 2.8 ± 0.6 kPa and 1.8 ± 0.6 kPa at 80 Hz, respectively (P = 0.004 at 100 Hz). Elastographic parameters could not differentiate benign from malignant thyroid nodules in these small sample sizes. Conclusion: We developed a method for the application of MRE to the study of thyroid gland pathology. The results show that the HT gland can be differentiated from normal thyroid. The clinical utility of this imaging modality in the diagnosis and management of thyroid disease awaits further study.