Fig. 2

Atypical perfusion characteristics in bilateral parathyroid adenomas. (a) 25 s 70 keV VMI, (b) 55 s 70 keV VMI, (c) 25 s 50 keV VMI, and (d) 25 s iodine overlay map are shown demonstrating surgically and pathologically proven bilateral parathyroid adenomas (arrows). In this case, a typical robust arterial phase enhancement with rapid washout is not shown (adenoma attenuation on the 25 s images was less than 100 HU). However, the presence of a fat plane separating the adenomas from the thyroid gland, location, and different appearance from normal lymph nodes enabled a confident pre-operative diagnosis in this case. The 50 keV VMI (c) is shown as an example of how DECT low energy reconstructions can accentuate the density of enhancing/iodine containing structures (compare c to a). DECT also enables creation of iodine overlay maps (d), highlighting the iodine content of tissues and enabling a quantitative estimation of tissue iodine content