Considerations on the origin of the inferior thyroid artery emerging from the subclavian artery determined by CT examination.

PURPOSE AND BACKGROUND: The specialized literature has a low degree of information regarding the origin of the inferior thyroid artery (ITA). Our study was performed on computed tomography angiographies (CTAs), and the following aspects were observed: the origin of the ITA from the subclavian artery (SCA) or thyrocervical trunk (TCT), taking note of the distance of the origin of the ITA in relation to the origin of the SCA or the corresponding TCT, as well as the origin of the ITA, comparing right to left and according to gender.

METHODS: Our study was realized on a total of 108 ITA (64 on the right side and 44 on the left, with 48 in male subjects and 60 in females), analyzed on CTA.

RESULTS: From the 108 arteries, we found the origin of ITA directly from the SCA in 31.48% of cases, and in 68.52% from the TCT. The distance between the origin of the right SCA and the origin of the corresponding ITA, was between 29.1 and 53.1 mm, while on the left side, the same distance was between 43.7 and 68.1 mm. The distance between the right TCT and the origin of the right SCA, was between 22.5 and 75.0 mm, and for the left side, it's between 48.7 and 56.8 mm.

CONCLUSIONS: The inferior thyroid artery is one of the arteries most susceptible to variations in terms of origin and size. With differences between the two sides (right and left), as well as differences related to gender.