Computer Technologies in Differential Diagnosis of Iodine-Deficient and Iodine-Induced Thyroid Dysfunction

Objective: Endemic goiter is the most common thyroid disease. In many regions of the world, endemic goiter may develop due to low iodine levels in the environment, and existing thyroid pathology is aggravated by iodine deficiency. Many modern medications for the treatment of cardiovascular, infectious and other diseases contain iodine and affect the function of the thyroid gland, which is especially significant in regions with iodine deficiency. All this requires additional efforts to establish the primary nature of the disease. This study aimed to develop and validate a method for differential diagnosis between iodine-deficient and iodine-induced thyroid dysfunction and to assess the risk of impaired hormone synthesis directly in the thyroid gland for people living in goiter-endemic areas, using computer technologies for both technical implementation and data analysis. Materials and methods: A retrospective study of 238 patients and a prospective examination of 92 patients with various thyroid diseases living in a moderate iodine deficiency zone were conducted, who underwent a study of thyroid density in Hounsfield units (HU) on a single-photon emission computed tomography scanner combined with an X-ray computed tomography scanner (SPECT/X-ray computed tomography). Results: In individuals without thyroid pathology and who had no contact with iodides, the average HU value determined by CT was 108.3 ± 6.4 HU, which is lower (p < 0.05) than in individuals who had contact with iodides (171.1 ± 4.2 HU). In individuals with iodine-induced thyroid pathology (hyperthyroidism, hypothyroidism), the average HU value was 179.9 ± 11.5 and 183 ± 13.6 HU (p < 0.01), respectively. The thyroid density in primary hypothyroidism and diffuse toxic goiter was 54.7 ± 7.3 HU and 85.0 ± 9.1 HU, respectively. In iodine-induced pathological conditions of the thyroid gland (iodine-induced hypothyroidism or hyperthyroidism), the thyroid density increases; in conditions of iodine deficiency with similar somatic manifestations, it was less than normal. Discussion: A well-functioning organ has a sufficient density in the range from 85 to 140 Hounsfield units. At a Hounsfield density (HU) below 85 units, the presence or risk of developing a thyroid dysfunction caused by iodine deficiency is determined, and at a thyroid density above 140 Hounsfield units (HU), the presence or risk of developing a thyroid dysfunction caused by excess iodine intake with iodine-containing drugs used in treatment is determined. X-ray computed tomography technology allows for preclinical diagnostics of hypothyroidism or hyperthyroidism by assessing the integrity of hormone-synthetic processes in the thyroid gland and to assume the manifestation of a disease caused by a clinically significant deficiency or excess of hormones (confirmed by a change in the level of hormones in the blood serum) within the next few months. Conclusion: CT technologies can be used in differential diagnosis of thyroid conditions to assess the risk of dysfunction. In complex differential diagnostics of thyroid dysfunction caused by iodine deficiency or excess (iodine deficiency or iodine-induced dysfunction of the thyroid hormone-producing function), the limit values for various etiological variants of thyroid dysfunction have been determined based on the density index. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2026.