Variation of Position of the Kidneys and Diaphragm in Patients Undergoing Repeated Suspension of Respiration

Abstract

The position of the upper poles of the kidneys in relation to the 12th thoracic vertebra was evaluated on each of the 3 nephrograms of 32 cooperative patients undergoing excretory urography during evaluation for hypertension. Mean change in kidney position relative to vertebral position between nephrograms varied from a mean 4.9 mm on films taken during inspiration to 7.7 mm on films obtained in expiration. Diaphragmatic positional changes could be evaluated in 12 patients; mean change in diaphragmatic position between nephrogram exposures was 8.0 mm. Considerable variation in diaphragm position does occur during successive breath-holding attempts for cross-sectional imaging.