[The color-coded duplex sonography and contrast-enhanced magnetic resonance tomography of scintigraphically cold thyroid nodules]

The role of the resistive index in Hashimoto's thyroiditis: a sonographic pilot study in children

OBJECTIVE

The role of Doppler ultrasonography in the diagnosis of diffuse thyroid diseases is not well established. In particular, Doppler ultrasonography findings in children with Hashimoto's thyroiditis are very limited. We examined gray-scale and Doppler ultrasound findings in Hashimoto's thyroiditis in children in an attempt to understand the feasibility of future prospective controlled studies.

MATERIALS AND METHODS

Twenty-one children with newly diagnosed Hashimoto's thyroiditis were recruited in the study. The patients were euthyroid or had subclinical hypothyroidism at the time of the ultrasonography examination. According to the color Doppler scale developed by Schulz et al., thyroid glands were classified into four patterns based on visual scoring and the mean resistive index (RI), which was calculated via measurements from both lobes, and these results were compared with gray-scale findings.

RESULTS

The mean RI value, calculated as the mean of the RI values of both lobes obtained from each patient, was found to be 0.57 ± 0.05 (range 0.48-0.67) cm/sn. The distribution of thyroid classifications was as follows: Pattern 0, n = 7; Pattern I, n = 6; Pattern II, n = 4; and Pattern III ("thyroid inferno"), n = 4. The mean RI values in patients with normal or near-normal gray-scale findings (n = 10) and patients with more substantial gray-scale changes (n = 11) were not significantly different and were lower than the values in normal children previously presented in the literature.

CONCLUSION

The results indicated that the RI may be more sensitive than other ultrasound parameters for the diagnosis of Hashimoto's thyroiditis.

Color Doppler sonography in hypothyroidism

BACKGROUND

The value of color Doppler sonography in thyroid disease continues to be a matter of debate. Over the past few years, several studies have proved unable to yield unequivocal results. Only a few studies concerning color Doppler sonography in patients with hypothyroidism have been published.

METHODS

89 patients with hypothyroidism have been evaluated. They were examined clinically; laboratory tests on thyroid function and color Doppler sonography have been performed. The color flow distribution and intensity were estimated and the fastest flow velocity (PSV) detectable with a pw-doppler was registered. The color pattern was graded from 0 to III as has been described by others and the color Doppler findings were then correlated to both the clinical picture and the laboratory results.

RESULTS

56 of the 89 hypothyroid patients showed pattern 0 with a PSV of 22 cm/s. In 33 patients different degrees of increased parenchymal color could be found with a concordant PSV: 16 patients showed pattern I with a PSV of 39 cm/s; 11 showed pattern II with PSV 58 cm/s, and 6 showed pattern III with PSV 63 cm/s. Regarding the corresponding clinical and laboratory variables, there was a very close correlation between color intensity and anti-Tg/anti-TPO antibody levels: pattern 0: anti-Tg 474 IU/ml, anti-TPO-Ab 810 IU/ml; pattern I: 1053/1733; pattern II: 1774/2432; pattern III: 1951/2633. Some correlation could also be found for the TSH values and the calculated volume of the thyroid gland, whereas the duration of hypothyroidism showed an inverse correlation to color intensity. (Pattern 0: TSH 3.1 mE/ml, volume 9.2 ml, duration 43 months; pattern I: 4.2 mE/l, 15.7 ml, 24 mos.; pattern II: 11.5 mE/l, 22.3 ml, 16 mos.; pattern III: 38.2 mE/l, 34.3 ml, 10 mos, respectively).

CONCLUSIONS

The color Doppler pattern of intense hypervascularization of the thyroid gland formerly attributed only to the hyperthyroid state of active Graves' Disease can also be seen in hypothyroidism. Our data support the concept that the color flow appearance is not the result of stimulated thyroid hormone production, but a measure of the activity of an autoimmune process.