Slide 1: The pt had a 4D CT to evaluate for parathyroid hyperplasia or adenoma. This study highlights the importance of the reformats and is a nice example of a sign described in the U/S literature and in AJNR (linked below) for the same sign on CT.
Slide 2: The thyroid U/S described the partially calcified nodule on the right (circle) and did not clearly see a parathyroid adenoma. Inferior to the right thyroid lobe there was mention of a partially calcified lesion (arrows) of unknown etiology.
Slide 3: Here are the 3 phases we scan using a low dose protocol developed by Diversified with the neck hyperextended. This simulates the position during surgery. It also elevates the glands for better visualization and reduces the radiation dose.
Slide 4: There are 2 rim calcified nodules on the right with the upper lesion having an outer rim of enhancing tissue laterally that washes out on the delayed image. On the left (*), is another soft tissue nodule that has early phase enhancement that washes out.
Slide 5: In addition, there are numerous arterial branches (arrow) superior to the right-sided calcified nodules and the left inferior thyroid artery (*) is enlarged and has a branch extending to the superior margin of the left sided nodule = “polar vessel sign”. The patient will soon have an FNA of the calcified nodules so although this is not classic for an adenoma we will see, but the left-sided nodule is classic for a parathyroid adenoma (surgery will confirm).
Read the AJNR article here.
References:
Bahl M, Muzaffar M, Vij G, Sosa J A, Roy Choudhury K, Hoang JK. AJNR: vol. 35, pp 578-581.