What condition is characterized by an infection leading to inflammation of the renal pelvis?

The condition characterized by an infection leading to inflammation of the renal pelvis is pyelonephritis. Pyelonephritis typically occurs when bacteria ascend from the lower urinary tract (such as the bladder) or through the bloodstream and infect the kidneys. This inflammation can cause symptoms such as fever, chills, flank pain, and painful urination, as the renal pelvis is the part of the kidney that collects urine and leads it to the ureter.

Other options do not relate to the anatomy or pathology concerning the kidneys. Pneumonolithiasis pertains to the presence of calculi (stones) in the lungs, which is unrelated to the urinary system. Dysphagia refers to difficulty swallowing, often related to disorders of the esophagus and not associated with kidney inflammation. Dyspnea involves shortness of breath and is typically related to respiratory conditions. Thus, pyelonephritis is distinctly focused on kidney infection and inflammation, making it the correct answer in this context.