Anatomical variation of thyroid veins on contrast-enhanced multi-detector row computed tomography

Abstract

ObjectiveThe objective of this study was to clarify the anatomical variation of thyroid veins into the systemic vein using contrast-enhanced multi-detector row computed tomography (MDCT). Design and methods: The subjects were 80 patients (34 males and 46 females; mean age, 50.1 years; age range, 15–92 years) with neck diseases who underwent MDCT. The number and location of inflow points of the thyroid veins into the systemic vein, and the length from the junction of bilateral brachiocephalic veins to the orifice of inferior thyroid vein were investigated by reviewing the axial and coronal images. ResultsAll superior thyroid veins were detected. Right and left middle thyroid veins were identified in 39 and 29 patients, respectively. Right inferior thyroid veins, left inferior thyroid veins, and common trunks were detected in 43, 46, and 39 patients, respectively; in five patients, two left thyroid veins were identified. All left inferior thyroid veins and 34 common trunks flowed into the innominate vein, while right ones had some variations in inflow sites. Mean lengths were 3.01±1.30cm (range, 0.5–6.19) and 2.04±0.91cm (0.5–4.4) in the left inferior thyroid vein and common trunk, and 1.96±1.05cm (0.81–4.8) and 1.65±0.69cm (0.63–2.94) in the right one flowing into the right internal jugular vein and the innominate vein, respectively. ConclusionsThe numbers and orifices of thyroid veins were identified at high rates on contrast-enhanced MDCT. This strategy can provide anatomical information before selective venous sampling for measurements of parathyroid hormone.