(6) In the absence of rapid-sequence, serializing-recording apparatus, it
may be necessary to perform circulation-time tests to ascertain the relationship of the
time interval between the commencement of the injection of the contrast medium and
the occurrence of opacification of specific blood channels. A substance such as ether,
sodium dehydrocholate (Decholin), sodium cyanide, fluorescein, or calcium gluconate is
injected into the vein and specific reactions (such as bitter taste, odor of breath,
yellowish coloration of the lips) manifested by the patient are noted and timed by a
stopwatch. This provides a reliable means for predicting when maximum opacification
of specific blood channels will occur and when the exposures should be made.
If fluorescein is to be used, the specialist must take the necessary steps to
darken the x-ray room and see that a Wood's lamp is on hand so that the
fluorescent coloration of the patient's lips can be detected the moment it
(7) When indicated, the examiner, the patient, and the specialist (including
any assistants) will rehearse the critical aspects of the injection procedure.
c. Positioning the Patient. The patient is usually placed in the horizontal
position, either prone or supine (see figure 3-10). If he is obliqued and supporting
material is used, the material must be free of any opaque substance. At the discretion
of the examiner, the patient may be placed in the upright position.
Figure 3-10. Position of patient and examiner preparatory to injecting the
contrast medium for angiocardiography.