THYROID PALPATION VERSUS HIGH-RESOLUTION THYROID ULTRASONOGRAPHY IN THE DETECTION OF NODULES

Detection of thyroid nodules by physical examination and high-resoluti on ultrasonography was compared using small groups of blinded, experie nced physician examiners working with a sample of 2441 persons from Es tonia, most of whom were Chernobyl nuclear reactor clean-up workers. A random subsample of 113 (5%) persons was subjected to triple control examinations With both physical examination and high-resolution ultras onography. Positive high resolution ultrasonographic findings were con sider ably more reproducible among different observers than were posit ive physical examination findings. Agreement between methods was poor. Nodules were found in 169 (6.9%) subjects by physical examination and in 249 (10.2%) subjects by high-resolution ultrasonography. Physical examination found only 53 (21%) of the 249 nodules found by high-resol ution ultrasonography. High-resolution ultrasonography did not confirm the existence of 115 (68%) of the 169 nodules found by physical exami nation. Only 6.6.4% of nodules less than 0.5 cm in diameter, as based on high-resolution ultrasonographic results, were detected by physical examination. Physical examination detection improved with increasing nodule size but was still only 48.2% for nodules larger than 2 cm. Phy sical examination was relatively effective in detecting nodules in the isthmus of the thyroid gland but much less so for nodules in the uppe r pole of the gland. Clinical evaluation and epidemiologic studies of nodular thyroid disease stand to benefit from the greater sensitivity and specificity of ultrasonographic examinations.