a. General. Nephrotomography is a special procedure for the sectional
representation of the parenchymal structures of the kidneys by the use of tomography
during radiopacification following the intravenous administration of a contrast medium.
This technique helps to obtain a clearer image of the renal parenchyma by blurring out
the image details of underlying and overlying structures.
b. Patient Preparation and Scheduling. Unless otherwise indicated, patient
preparation and scheduling for nephrotomography is essentially the same as for
(1) Two AP radiographs of the abdominal region are obtained, one by use of
conventional radiographic technique, the other by tomography. The two films are
processed immediately and presented to the examiner for reading. They serve as
control films and as a means for checking the correctness of the technique factors.
(2) Any necessary adjustments in regard to positioning of the patient are
made, the tomographic fulcrum is set at the correct elevation, and the contrast medium
is introduced. Usually, the introduction of the contrast medium is done as for
nephrography. The numbers of exposures to be made during radiopacification of the
renal parenchyma, as well as the exact exposure time-intervals to be used, are
predetermined by the examiner according to circulation time.
(3) All films should be developed immediately after exposure and presented
to the examiner for reading prior to releasing the patient.
a. General. Urethrograms are accomplished by radiography of the urethra after
filling with a suitable contrast medium.
b. Patient Preparation. No special preparation of the patient is required, but
the patient is requested to void just prior to examination.
(1) Either a conventional x-ray unit equipped with a Potter-Bucky diaphragm
or a radiographic-urological table unit.
(2) Sandbags or cellulose positioning blocks for supporting and immobilizing
the patient in the required position.
Routine layout for administration of contrast media.