摘要
The diagnosis of a retrosternal thyroid growth (RTG) causes extended surgical exploration and a different surgical treatment planning (partial sternotomy, thoracotomy) and is usually made by the help of thyroid scintigraphy and ultrasonography. But both examinations have problems in determining the retrosternal thyroid extend in the complex anatomy of sternal bone and often pathologically altered manubrioclavicular joints (MCJ). This study evaluates the variation of anatomical structures in the upper sternal region, the position of the sternal markers during scintigraphy, and the frequency of enhanced bone metabolism of the MCJs. For this aim, the positions of the upper edges of the MCJs were measured by X-ray fluoroscopy in 50 consecutive patients. To prove the exactness of an external marker as used in thyroid scintigraphy, the variation of the marker position was also determined. The activity in the MCJs was measured semiquantitatively with bone scintigraphy in further 100 patients (mean age: 62.3 yrs, SD: 14.2 yrs). As results, the upper edges of the medial clavicular edges exceed the upper margin of the sternal edge up to 2.7 cm. The distance between the medial clavicular edges ranged from 2.3 - 5.6 cm. The position of the sternal marker was correct in the horizontal deviation (mean: 0.1 cm, SD: 0.48 cm) but too high in the vertical position (mean: 2.2 cm, SD: 0.67 cm). During bone scintigraphy, the MCJs showed no enhanced activitity in 75/200 joints, medium activity in 96/200 joints, and strong enhanced activity in 29/200 joints. In consequence, a high variability in the position of the anatomical structures has to be considered together with a high amount of degenerative alterations. The position of the sternal marker was inappropriate in the vertical direction and overestimated a possible retrosternal growth.
The diagnosis of a retrosternal thyroid growth (RTG) causes extended surgical exploration and a different surgical treatment planning (partial sternotomy, thoracotomy) and is usually made by the help of thyroid scintigraphy and ultrasonography. But both examinations have problems in determining the retrosternal thyroid extend in the complex anatomy of sternal bone and often pathologically altered manubrioclavicular joints (MCJ). This study evaluates the variation of anatomical structures in the upper sternal region, the position of the sternal markers during scintigraphy, and the frequency of enhanced bone metabolism of the MCJs. For this aim, the positions of the upper edges of the MCJs were measured by X-ray fluoroscopy in 50 consecutive patients. To prove the exactness of an external marker as used in thyroid scintigraphy, the variation of the marker position was also determined. The activity in the MCJs was measured semiquantitatively with bone scintigraphy in further 100 patients (mean age: 62.3 yrs, SD: 14.2 yrs). As results, the upper edges of the medial clavicular edges exceed the upper margin of the sternal edge up to 2.7 cm. The distance between the medial clavicular edges ranged from 2.3 - 5.6 cm. The position of the sternal marker was correct in the horizontal deviation (mean: 0.1 cm, SD: 0.48 cm) but too high in the vertical position (mean: 2.2 cm, SD: 0.67 cm). During bone scintigraphy, the MCJs showed no enhanced activitity in 75/200 joints, medium activity in 96/200 joints, and strong enhanced activity in 29/200 joints. In consequence, a high variability in the position of the anatomical structures has to be considered together with a high amount of degenerative alterations. The position of the sternal marker was inappropriate in the vertical direction and overestimated a possible retrosternal growth.
