[The importance of quantitative grey-scale analysis of the sonogram in "diffuse" thyroid diseases].

A sonographic grey scale (gs) analysis of the thyroid gland was retrospectively (1985-1986) performed in 248 patients with normal sized thyroid glands or "diffuse" thyroid diseases. During the examination the physical parameters for gain, far and near gain were constant. The normal value (means +/- 2 s) in 95 patients with normal sized and euthyroid thyroid glands was lower in females (gs: 14 +/- 4) than in males (gs: 16 +/- 6), children had obviously lower patterns (gs: 7.1), adolescents had low normal patterns (gs: 11). The echogenicity increased with increasing thyroid volumes. In patients with autoimmune thyroid diseases an obvious low echogenicity could be demonstrated (Hashimoto's thyroiditis, gs-SEM: 8.3 +/- 1.5; Grave's disease, gs-SEM: 6.7 +/- 1.2) (SEM = standard error of the mean). Euthyroid patients with microsomal antibody titers showed low normal grey scale patterns (gs: 10.9 +/- 3). In patients after subtotal thyroidectomy the grey scale pattern decreased with decreasing volume of the residual thyroid gland. The grey scale pattern increased years after surgery. The subjective grading of the grey scale pattern was different from the quantitatively measured pattern in 18% of the patients with glands of normal size.