MRI and ultrasound detection of asymptomatic thyroid nodules in hyperparathyroidism.

A retrospective MRI and ultrasound (US) study of 50 patients with hyperparathyroidism and no history of thyroid disease was done. The purpose was to compare the sensitivity of both methods in the detection of asymptomatic thyroid nodules, as well as to determine the prevalence of thyroid abnormalities in patients with hyperparathyroidism. All the patients underwent MR and 33 were also studied by high-resolution US. Magnetic resonance imaging was performed on a 1.5 T unit, using T1-(500-700/20) and T2-(2,000/20 and 70) weighted images. Axial sections (5 mm with a 1 mm interval between them) were obtained along the neck. Ultrasonography was performed using a 10 MHz linear array transducer. The prevalence of thyroid nodules was 46% in the 50 patients studied by MR imaging. In the subgroup of patients studied by both methods, US depicted nodules in 48% of patients, and MR depicted nodules in 45%. Magnetic resonance imaging and US detected a high frequency of thyroid nodules in patients with hyperparathyroidism. This high frequency makes the detection of an intrathyroidal parathyroid adenoma problematic.