Since the use of opaque solutions, as introduced by Voelcker and von Lichtenberg 1 in 1906, pyelography has made tremendous strides. The toxicity of the agents used has been lessened, and the roentgenogram has been materially improved.
The efforts of Braasch, 2 and his writings from 1909 and onward stimulated its use and proved its value. At the time of its introduction, collargol was most generally used. Reports as to its toxicity did not find their way into the literature prior to 1913, when Braasch 3 stated that he had observed the retention of the fluid for as long as several weeks. In 1913, Thomas4 of the Mayo Clinic stated that the overdistention of the pelvis and the resulting colic might be caused from the use of the syringe and suggested the gravity method. He devised an apparatus that bears his name.
A summary of the writings in 1914