Normal thyroid size versus goiter--postmortem thyroid weight and ultrasonographic volumetry versus physical examination.

Abstract

The data on postmortem thyroid weight and on thyroid volume estimation with the aid of ultrasound are briefly reviewed and correlated with indicated or presumed intake of iodine in the appropriate area. The well known negative correlation between iodine intake and thyroid size may be supported even by this approach which shows that as a normal thyroid volume may be taken that obtained in areas with sufficient iodine intake such as Iceland, Sweden, Netherlands and USA. In these countries the average thyroid volume was found by various authors to be in a range of about 8 to 12 ml (or g) for females and about 11 to 15 ml (or g) in males which is approximately 10 ml (or g) less than the values considered as normal until recently. The comparisons of the data on postmortem weight or sonographically determined volume of the thyroid with palpatory findings showed that the same stage of thyroid size according to various recommended scales as found by palpation or inspection may correspond to a great variety of actual volumes and thus that the palpation may be considered as highly inaccurate method for precise estimation of thyroid size. From this view it may be recommended predominantly for large scale and low cost field epidemiological studies, while a most favourable ultrasonographic volumetry should be used for a majority of basal clinical studies and field surveys.