Thyroid imaging: comparison of high-resolution real-time ultrasound and computed tomography.

High-resolution real-time ultrasound (US) and computed tomography (CT) were compared in 48 patients with a clinical diagnosis of thyroid abnormality and also correlated with biopsy or surgery. The modalities were considered comparable in 38 cases (79%), while CT was superior in 5 and US in 5. CT illustrated substernal extension of a goiter, demonstrated a 5-mm nodule not seen in US, showed 2 cases of thyroiditis better than US, and diagnosed a suspected thyroid mass as a lipoma anterior to the thyroid. US detected 4 nodules not seen on CT and resolved contiguous nodules that appeared to be a single nodule on CT. Both techniques lacked histopathological specificity. CT appears to be advantageous in detecting substernal thyroid extension and confirming thyroiditis, while the ability of US to detect small nodules makes it the procedure of choice in evaluating suspected intrinsic thyroid abnormalities.