What does the term "retrograde pyelography" describe?

The term "retrograde pyelography" refers specifically to a radiographic procedure that involves the use of contrast dye to visualize the urinary tract, particularly the renal pelvis and ureters. In this procedure, contrast material is introduced in a retrograde manner, meaning it is injected into the urinary system through the urethra and bladder, allowing for detailed images of the kidneys and urinary tract structures to be obtained. This imaging technique is especially useful for diagnosing conditions such as obstructions, stones, tumors, or any anatomical abnormalities within the urinary system.

The other choices do not pertain to the urinary tract. Visualization of bronchial tubes is achieved through bronchography, not retrograde pyelography. Non-invasive methods for assessing cardiac health are more aligned with echocardiography or nuclear stress tests, neither of which involves the urinary tract. Lastly, techniques that examine the gastrointestinal tract would involve modalities like fluoroscopy or endoscopy, which are unrelated to retrograde pyelography. Thus, the correct choice accurately encapsulates the specific function of retrograde pyelography within the field of medical imaging.