Figure 4-15. Demonstration of fluid level in the chest cavity with the patient in the erect
position and the central ray projected in the horizontal direction.
Figure 4-16. Demonstration of fluid level accomplished with the patient in the lateral
decubitus position and the central ray projected in the horizontal direction.
c. Oftentimes, in order to accomplish fluid-level studies of a special kind, it is
necessary to introduce a contrast medium (for example, Lipiodol or a similar substance)
into the body cavities under investigation.
When executing injected sinus procedures, care should be taken to see
that the injected substance is not expelled. In case the patient reports to
the x-ray department with the contrast medium already injected,
exposure should be made immediately upon his arrival, if possible.