[Digital subtraction dacryocystography and sialography].

Fourteen examinations of the tear ducts and 21 sialograms were performed using digital subtraction and conventional techniques. In nine of the former and 15 of the latter, digital subtraction produced better results, in the remainder conventional technique was equally good. The advantages of digital subtraction are due to the removal of superimposed structures of the skull. Dose measurements at the level of the lens of the eye showed a greatly reduced radiation dose when using digital subtraction, as compared with conventional dacryocystography. Digital subtraction techniques with pulsed radiation and the ability to perform pixel shift is an optimal method for performing radiological examinations of the tear ducts and salivary glands.