Selenium 75 selenomethyl cholesterol: a new agent for quantitative functional scintigraphy of the adrenals: physical aspects.

Fifty-two patients with suspected or known adrenal disorders have been studied with 75Se selenomethyl cholesterol using a rectilinear scanner or gamma camera computer system. Radiation dosimetry was estimated from the blood clearance and whole body retention of 75Se selenomethyl cholesterol. A method of quantitation of adrenal uptake is described, use of which is essential for the separation of normal from hyperactive adrenal glands. The adrenal depth was found to vary between 4.4 and 12 cm. The lack of need for thyroid suppression and the availability and ease of handling and storage of 75Se selenomethyl cholesterol make it preferable to 131I iodo-cholesterol derivatives and the current agent of choice for adrenal imaging.