Misako NAKAHARA, Mitsuo MORITA, Shiro NOGUCHI, Ayako TAHARA, Masaaki TAMARU, Mitsuo ADACHI

Noguchi Thyroid Clinic and Hospital Foundation

キーワード : Thyroid volumetry, Coupling medium, Ultrasonography, Radioiodine therapy

The thyroid volumes of 161 Graves' disease patients were determined by high resolution (7.5 MHz) ultrasonography. Using a coupling medium in which a 22-gauge (G) wire was inserted as a marker, the length (a), breadth (b) and depth (c) of each lobe and isthmus were measured. The thyroid volume was calculated following the spherical ellipsoid formula: V=(π/6)a×b×c. One hundred patients underwent surgery for Graves' disease within a week of undergoing an ultrasonic examination. A good correlation could be observed between thyroid volumes estimated by ultrasonography and thyroid weights obtained from surgery (r= 0.929). Comparative measurements revealed a tendency towards overestimation of thyroid weight when calculated via an iodine-131 scintigram. We conclude that this simple method of high-resolution ultrasonography could be helpful in the follow-up treatment of goitrous patients and in determining the iodine-131 dosage at radioisotope therapy for Graves' disease.