Figure 1: Comparison of 6-[¹⁸F]F-l-DOPA vs [¹⁸F]FDG MTC labelling in MEN2A transgenic mice. a For each mouse, the left panel shows 6-[¹⁸F]F-l-DOPA labelling and the right panel shows [¹⁸F]FDG labelling. Top to bottom sagittal, coronal and transaxial section of the mouse, with red arrows indicating the labelled MTC and white arrows indicating the [¹⁸F]FDG unspecific labelling in the neck. The transaxial section is centred on the thyroid, which appears at the bottom of the images for the two other sections. The images represent the sum of the frame acquired during 1.5h after i.v. injection of the radiotracer. b–e Whole section of thyroid gland in RET-MEN2A transgenic mice after haematoxylin and eosin staining. b–d correspond to the thyroid of each of the three mice presented in a. b corresponds to mouse 1 and is oriented as the coronal PET section, c to mouse 2 and is oriented as the coronal PET section and d to mouse 3 and is oriented as the transaxial PET section. F follicles, P parathyroid gland, T trachea, C carcinoma. Carcinomas are clearly present on these three thyroids. e corresponds to a thyroid of a 17-month-old mouse that was labelled neither by 6-[¹⁸F]F-l-DOPA nor by [¹⁸F]FDG (data not shown): in that case the thyroid had a normal aspect even by histopathological study. The scale bar represents 1mm. (Reprinted from Pestourie C, Thézé B, Kuhnast B, et al. PET imaging of medullary thyroid carcinoma in MEN2A transgenic mice using 6-[¹⁸F]F-l-DOPA. Eur J Nucl Med Mol Imaging. 2010;37:58-66, with kind permission from Springer Science and Business Media.)