Abstract
The primary enlarged x-ray image is produced by a reduction of the focal-film-distance to 80 cm at a given focal size of 0·15 mm. The advantages of this technique as compared to conventional x-ray methods are exemplified with x-ray images from the shoulder joint of a European hamster, a pseudoarthrosis in the foreleg of a beagle, and a renovasography of a rat. The principles of the technique and its significance for investigations using small laboratory animals are discussed.