Which of the following describes the classic radiologic findings in gout?

The classic radiologic findings in gout are characterized by small punched-out lesions that typically appear around the joints, particularly in areas like the metatarsophalangeal joint of the big toe. These lesions are the result of bone erosion due to the inflammatory processes associated with gout, which is caused by the deposition of monosodium urate crystals in the tissues and synovial fluid.

Interosseous tophi, which are aggregations of urate crystals, can also be visualized on imaging. These tophi appear as soft tissue masses in patients with chronic gout and further support the diagnosis, particularly in longstanding cases. The presence of these two features—punched-out bone lesions and tophi—helps establish a definitive diagnosis of gout, especially when correlated with clinical symptoms such as recurring joint pain and swelling.

The other options describe different conditions or findings associated with various arthropathies. For instance, large osteophytes and joint space narrowing are more characteristic of osteoarthritis. Subchondral cysts and joint effusion are common in conditions like rheumatoid arthritis, and joint erosion and narrowing of bones can also occur in other types of arthritis, not specifically indicative of gout. Thus, option B accurately represents the hallmark radiologic findings of gout.