Abstract:

Abstract Objective: Pre-surgery evaluation of large thyroid glands is done by neck computed tomography (CT) and by thorax CT to show retrosternal extension. Our aim was to compare the diagnostic accuracy of neck CT and thorax CT imaging to detect retrosternal extension of the thyroid gland. Material and Methods: The tomography scans of 20 patients with enlarged thyroid glands, who had gone under neck and thorax CT in the same session were retrospectively reviewed. Neck tomograms were taken in supine position with arms down, thorax tomograms in supine position with arms above the head level. The size, heterogenity and level of retrosternal extension were reviewed by two experienced radiologists independently. Results: The retrosternal extension of the thyroid gland was viewed as located lower in thorax tomograms compared to neck tomograms. The difference was less than 10 mm in 8 cases, between 10 mm-15 mm in 8 cases, more than 15 mm in 4 cases. There was no difference between two modalities in detecting the size and heterogenity of the thyroid gland. Conclusion: Our results show that there is discrepancy between the two techniques, with the apparent retrosternal extent of the goiter lower when the arms were overhead. Retrosternal goiters should be imaged with the patient’s arms by the sides, because this is the position the patient will be in during surgery.

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