(h) The needle is then connected to the plastic tubing and syringe filled
with sterile saline solution. The ease of flow throughout the injection route is checked
by means of barbotage.
(i) The stopcock is then closed. The syringe is disconnected and filled
with approximately 20 cc of the contrast solution. The syringe is reconnected and the
stopcock complex adjusted. To make sure that the needle is well within the lumen of
the aorta, the examiner may request an exploratory exposure the instant after injection
of a relatively small amount of the contrast solution. This film must be processed
immediately and presented to the examiner for reading.
(3)
(a) The examiner withdraws a few cubic centimeters of blood into the
barrel of the syringe.
(b) When everything is in complete readiness, all participants alerted,
x-ray unit energized, cassette in the Bucky tray, and technique factors set, the examiner
gives the "Ready," signal to the specialist and starts the injection. At that instant, the
examiner gives the signal "Now," or "Shoot," and the specialist makes the first
exposure.
(c) The injection needle is removed by the examiner and the x-ray
specialist (or an assistant) changes cassettes.
(d) Subsequent exposures are made at predetermined intervals.
Exposures made from 2 to 4 seconds after completion of the injection will usually
demonstrate the venous return.
(e) To obtain optimum radiographic quality in the aortogram, grid
technique must be used. The exposure time should not exceed 1/10 second. Increase
the kVp 10 percent above that which would be used for a similar projection without
contrast medium, adjusting the mA to keep density constant. A pilot film should be
made to check technique.
b. Aortography--Retrograde Method.
(1) Patient preparation and preliminary procedure. In general, the
preparation of the patient and the preliminary procedure are the same as for the
translumbar percutaneous method described above, with the following exceptions:
(a)
The patient is adjusted in the supine position on the x-ray table.
(b) After aseptic preparation and local anesthesia, the femoral artery is
the region of Scarpe's triangle located.
MD0959
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