title: [Diagnosis of malignant thyroid tumor using high-frequency ultrasonography with piezoelectric transducer, soft X-rays and aspiration biopsy cytology].
abstract: Diagnosis of thyroid cancer has been based mainly on palpation and also soft X-rays because of its calcification. As the gland itself is very small and Aspiration Biopsy Cytology (ABC) has had a high level of diagnostic accuracy the clinical significance of ultrasonography did not become apparent for a long time. However, recently it has become possible to carry out detailed study and to detect suspect histological structures, following the remarkable progress which has been made in ultrasonography, using a high-frequency piezoelectric transducer. A single mechanical arch scanner, with a piezoelectric 7.5-MHz transducer (SAL-25A Toshiba Corp.) was employed for examination using the water bath method. The rates of correct diagnosis for each of the above methods among 847 nodular goiters including 184 malignant tumors which were microscopically examined were shown to be: ultrasonography 89.7%, soft X-rays 66.9% and ABC 86.4%. Ultrasonography was capable to revealing a few cases which could not be shown by ABC or soft X-rays. Using these three methods jointly, there was 1 false positive and no false negative cases. This study revealed that combined diagnosis with ultrasonography using a high-frequency piezoelectric transducer improved the accuracy of examination of malignant thyroid tumors.
mesh_terms: D001707:Biopsy, Needle; D006801:Humans; D011859:Radiography; D012016:Reference Values; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging; D014159:Transducers; D014463:Ultrasonography / Q000379:methods*