Radiology, Vol 197, 213-219, Copyright © 1995 by Radiological Society of North America
Hashimoto thyroiditis: correlation of MR imaging signal intensity with histopathologic findings and thyroid function test results
S Takashima, H Fukuda, N Tomiyama, N Fujita, Y Iwatani and H Nakamura
Department of Radiology, Osaka Teishin Hospital, Japan.
PURPOSE: To assess the clinical usefulness of magnetic resonance (MR)
imaging of the thyroid gland in Hashimoto thyroiditis. MATERIALS AND
METHODS: Signal intensity ratios on spin-echo T1-, proton-density-, and
T2-weighted images were measured prospectively in 37 patients with
Hashimoto thyroiditis (33 women, four men; mean age, 51 years) and in 10
patients with thyroid lymphoma (six women, four men; mean age, 68 years).
Signal intensity ratios were correlated with histopathologic findings and
thyroid function test results with stepwise regression analysis. Diagnosis
of lymphoma with signal intensity ratios was compared with morphologic
diagnosis by using receiver operating characteristic curves. RESULTS: A
proton-density-weighted signal intensity ratio of 1.54 or higher indicated
hypothyroidism (R = .445, P = .008; 29% sensitivity [two of seven
patients]). A T2-weighted signal intensity ratio of 5.08 or higher
suggested advanced glandular destruction (R = .677, P < .001). Diagnosis
by each observer was better than diagnosis with signal intensity ratios.
CONCLUSION: MR imaging results can reflect thyroid function and
histopathologic findings in the thyroid gland and help discriminate
malignant lymphoma from Hashimoto thyroiditis.
