What is the term for the administration of contrast directly into the bladder via catheter?

The term for the administration of contrast directly into the bladder via a catheter is known as a cystogram. This procedure involves instilling contrast media into the bladder, typically using a catheter, to visualize the bladder's structure and function through imaging techniques. Cystograms are particularly useful for assessing bladder conditions, such as trauma, tumors, or anatomical abnormalities.

In this context, it is important to distinguish a cystogram from the other terms presented. Retrograde urography refers to the imaging of the urinary system after contrast is injected retrograde into the ureters, not the bladder directly. An esophagogram focuses on visualizing the esophagus, often to assess swallowing or structural issues, which is unrelated to bladder procedures. A myelogram involves the injection of contrast into the spinal canal to visualize the spinal cord and nerve roots, again unrelated to bladder imaging or catheterization.

Thus, the correct identification of this procedure as a cystogram is based on its specific focus on the bladder and the method of contrast administration.