201TlCl scintigraphy in 19 cases of thyroid follicular nodules after 99mTcscintigraphy visualised a thyroid cold nodules. The results showed that 201TlCl uptakein cold nodules of 6 cases still remained deficient. 201TlCl uptake of 10 nodules wasthe same as normal throid tissue
whereas that of 3 nodules higher than normalthyroid tissue. The overall positivity was 13/19.