The introduction by Sir John Thomson Walker to this small book of scarcely a hundred pages strikes the keynote in regard to this modern method of urologic diagnosis. Three points stressed by him will bear verbatim quotation.
I may be permitted to lay stress on three points. The method is not one for the occasional dabbler in cystoscopy. There are dangers connected with pyelography that make it desirable that only those practiced in the use of the cystoscope and accustomed to the delicate manipulations necessary for ureteral catheterization should undertake the work.
The second point is that a pyelogram, when obtained, must be read by the experienced eye if grave mistakes in interpretation and consequently in operation are to be avoided.
The third point is that only those cases should be submitted to pyelography in which the information desired could not be obtained equally well by other less severe methods