Fig. 1From: Opinion: leading position of ultrasound in decision algorithm for small papillary thyroid carcinomaThyroid nodule labelling and numbering at study outset (and follow- up). A Axial US scan of upper right lobe of thyroid gland. B Sagittal scan of right lobe. C Axial scan of right lobe and isthmus. D Diagram. Nodules are numbered from upper to lower lobe from right to left. In case of multifocal malignant nodule, various tumour foci are identified on US scan (A–C) as N1*, N3*, N4* and N5*, and reported on the diagram (D). Sum of each focus is calculated: 7 mm (upper right lobe) + 3 mm (lower right lobe) + 3 mm (isthmus) + 2 mm (isthmus) = 15 mm (pT1b) (D). Note that considering the only main tumour focus (N1) leads to pT1a diagnosis according to the TNM classification. Echogenic foci should be differentiated from comet tail artefacts and are considered as psammoma body microcalcifications and be reportedBack to article page