(2) Hypaque 50 percent, Conray 50 percent, and Renografin 60 percent are
water-soluble injectables of relatively low concentrations. Frequently used for
urographic studies, they are generally termed urographic media. These media can also
be employed in contrast examinations of joints and portions of the cardiovascular
system.
(3) The more concentrated water-soluble injectables are usually reserved
for examinations of the heart and great vessels. Hypaque M (75 percent or 90 percent
concentration), Angio-Conray 80 percent, and Renografin 76 percent are examples of
this group, generally titled angiocardiographic media.
c. Water-Soluble Noninjectables. The other kind of water-soluble radiopaques
is called noninjectable. Retrografin is a typical example. They are primarily used in
retrograde studies of the urinary tract. These media are modified injectables. For
instance, Retrografin is essentially Renografin with neomycin, an antibiotic, added. In
this case, contrast media and antibiotics are mixed to reduce the danger of infection
following retrograde examinations.
1-24. VISCOUS AND/OR OILY RADIOPAQUES
a. Introduction. Ethiodol, Salpix, Pantopaque, and Dionosil are examples of a
group of contrast media called viscous and/or oily radiopaques. These viscous or oily
radiopaques are rarely used today since the exams that used them have been replace
by exams done in other modalities.
b. Viscosity and Oiliness. The reason for the "and/or" above is understood if
an analogy is made with a jar of honey, a can of light lubricating oil, and a can of motor
oil. The honey is viscous, meaning thick or resistant to flow, but not oily. The light oil is
oily, but not viscous. The motor oil is both viscous and oily. The contrast media in this
c. Uses of Viscous and/or Oily Media. The bronchial tree can be studied by
introducing Dionosil or a similar medium. Dionosil, a viscous and oily medium, is used
to prevent flow of the contrast agent into the alveolar sacs, and because it is absorbed
by the lungs leaving no residue. Salpix is usually used to delineate the uterus and
fallopian tubes in hysterosalpingography. Salpix is a water-soluble, viscous medium.
Ethiodol, an oily viscous medium, is usually employed in the radiological examination of
the salivary glands. Pantopaque that is both viscous and oily is used in myelography
(the examination of the spinal cord).
1-25. RADIOLUCENT MEDIA
a. Introduction. Alimentary tract radiopaques, water-soluble radiopaques, and
viscous and/or oily radiopaques are all classified as radiopaque media because they
increase photon absorption. Contrast media that decrease photon absorption are
termed radiolucent media.
MD0959
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