Roentgenography of hip-joint using tubus in infants

Roentgenography of hip-joint using tubus was discussed. This technique has been made at St. Marianna University, School of Medicine, in order to reduce the exposure dose in x-ray examination of congenital dislocation of hip-joint. The tubus is designed to butterfly-shaped. Only the site which is necessary for roentgenography of hip-joint is exposed, and the sexual gland is outside exposure. The exposure dose of the sexual gland using tubus is 1/10 in female infants and 1/30 in male infants of those without tubus (6.7 mR in male infants, 2.0 mR in female infants). There are some advantages in the tubus: it is clinically used for both sexes as well as reducing exposure doses, and it can be used widely from neonates to infants. (Serizawa, K.)