Kinetic Urography

Abstract

Fluoroscopy of the peristalsis of the upper urinary tract was introduced in 1927 by Legueu et al. The urine was found to be propelled by a peristaltic contraction ring similar to the annular contraction described by Engelmann (1869). The ring could be observed to travel alternately from one of the main branches of the pyelocalyceal system and to spread over the renal pelvis (the confluence of the main branches) and over the entire ureter. Its motion was continuous and its speed close to 3 cm/s. The shortest contraction interval was about 5 s. The morphodynamics in the pyelocalyceal system were complex and rapid, and since kinetic recording was not yet clinically applicable certain morphodynamic processes could not be adequately analyzed, particularly those preceding the appearance of the contraction ring in a main branch. In supplementing fluoroscopy with single exposures as brief as 0.05 s Legueu et al. were able to demonstrate that on its transit over the main branches the contraction ring produced a retrograde injection of the liquid into the calyces, distending each calyx in a rapid sequence terminating within a few seconds. This injection was similar to the injection into the ureter, indicating that the ring might subsequently pass on into the calyces just as it did into the ureter and suggesting the possibility of an antegrade peristaltic contraction preceding the appearance of the ring in a main branch. The morphodynamics of the ureter proved to be far less complex and more conspicuous than those of the pyelocalyceal system, hence more accessible to analysis. The liquid injected by the contraction ring when running in one of the main branches immediately elongated according to the dimensions of the ureter, its forward end running quickly through the lumbar segment and stopping short at the junction between the lumbar and pelvic segments. As the steadily advancing contraction ring approached the junction the bolus grew shorter and thicker, i.e. it distended, and at a certain moment it was injected into the pelvic segment in the same way it had been injected from the renal pelvis.