Subcutaneous injection of 99mTc-pertechnetate for neonatal thyroid scintigraphy

A 9-day-old female infant with congenital hypothyroidism presented for thyroid scintigraphy. Multiple attempts including the "intravenous team" failed to establish peripheral access for administration of 99mTc-pertechnetate. We administered 99mTc-pertechnetate subcutaneously into the upper arm. Rapid absorption (85% of the dose in 20 minutes) was documented on dynamic images with physiological uptake, allowing diagnostic thyroid scintigraphy at 35 minutes that revealed ectopic sublingual thyroid. Subcutaneous injection allowed us to avoid traumatic and risky central vascular access procedure. When peripheral intravenous access cannot be obtained, 99mTc-pertechnetate can be administered subcutaneously for diagnostic thyroid scintigraphy, which is particularly useful in neonates.