The advent of the roentgen ray marks the beginning of the period which is rightly characterized as the period of accurate and intelligent treatment of ureteral calculi. The roentgen ray, while contributing so largely to the diagnosis and treatment of this condition, is also accompanied by certain sources of error, chief of which are: (1) failure to demonstrate a calculus when present; (2) a wrong interpretation of shadows found in the plate, and (3) failure to find at operation a calculus which was definitely demonstrated by the roentgen ray to be in a "given portion" of the ureter.
1. With improved technic, failure to demonstrate the presence of a stone when present now makes up a very small percentage of cases. This small percentage can be still further reduced by subsequent examinations with the roentgen ray, by a careful rereading of the plates, by intra-ureteral injections of colloidal silver salts,
KRETSCHMER HL. THE RETROGRADE MOVEMENT OF URETERAL CALCULI. JAMA. 1918;71(17):1355–1359. doi:10.1001/jama.1918.02600430001001