Schematic representation of study measurements after total thyroidectomy in the Maastricht University Medical Centre.

<p>Blue arrows indicate moment of study measurements. FT4 indicates free thyroxine, TSH indicates thyroid-stimulating hormone, levothyroxine treatment indicates pharmacological levothyroxine suppletion that suppresses endogenous TSH. I¹³¹ indicates radioactive iodine, used for radioactive ablation therapy of thyroid gland remnants after thyroid gland resection for well-differentiated thyroid carcinoma. I¹²⁴ indicates a proton-rich isotope of iodine used as a radiochemical for determination of thyroid gland remnants after thyroid gland resection for well-differentiated thyroid carcinoma.</p

Consort 2010 flow chart.

<p>Consort 2010 flow chart.</p

BAT activity, BMR and NST before and after levothyroxine therapy.

<p>Brown adipose tissue (BAT) activity before and after levothyroxine substitution therapy. (A) Basal metabolic rate (BMR) in joules per minute. (B) Non-shivering thermogenesis (NST) before and after levothyroxine replacement therapy. (C) BAT activity in Mean Standard Uptake Values (SUV mean) before and after levothyroxine therapy. Subject indicated with ^X is also depicted in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0145049#pone.0145049.g002" target="_blank">Fig 2D and 2E</a>. (D) Transversal CT (top) and PET/CT fusion (bottom) slice of the supraclavicular region demonstrating ¹⁸F-FDG-uptake in BAT locations (white arrows) after cold exposure in hypothyroid state. (E) Transversal CT (top) and PET/CT fusion (bottom) slice of the supraclavicular region demonstrating ¹⁸F-FDG-uptake in BAT locations (white arrows) after cold exposure in subclinical hyperthyroid state.</p