Differentiation of Shock Thyroid on Enhanced Chest CT from Hashimoto’s Thyroiditis and Multinodular Goiter—A Pilot Study in Ten Patients with Shock Thyroid

Background/Objectives: The CT features of shock thyroid are enlarged thyroid glands with inhomogeneous enhancement and peri-thyroid fluid. However, if peri-thyroid fluid is absent or equivocal, shock thyroid may be confused with multinodular goiter or Hashimoto’s thyroiditis on enhanced chest CT. Thus, we investigated CT characteristics that differentiate shock thyroid from multinodular goiter or Hashimoto’s thyroiditis. Methods: We retrospectively identified 10 patients with shock thyroid who underwent enhanced chest CT and thyroid function tests (TFT) from March 1, 2025, to May 31, 2026. A control group consisted of 21 randomly selected patients with multinodular goiter (n = 10) or Hashimoto’s thyroiditis (n = 11). CT features, including capsular sparing with low attenuation, a prominent vessel sign, and a nodule with a sharp margin, were compared between groups. Results: There was a significant difference in the prevalence of capsular sparing with low attenuation between the shock thyroid and control groups [90.0% (9/10) versus 0.0% (0/21), p < 0.001]. There was also a significant difference in the frequency of a prominent vessel sign between the shock thyroid and Hashimoto’s thyroiditis groups [0.0% (0/10) versus 63.6% (7/11), p < 0.001], and a nodule with a sharp margin between the shock thyroid and multinodular goiter groups [0.0% (0/10) versus 80.0% (8/10), p < 0.001]. Conclusions: CT findings such as capsular sparing with low attenuation accompanied by peri-thyroid fluid collection may represent potential imaging markers of shock thyroid and require validation in a larger multicenter cohort.