Final answer:
Uric acid stones are often radiolucent on plain film radiography, making them less visible compared to other types of kidney stones like calcium oxalate stones, which are more radiopaque.
Step-by-step explanation:
Among the major types of kidney stones, uric acid stones are commonly known to be radiolucent, which means they are often poorly visible or completely invisible on plain film radiography. Unlike calcium oxalate stones, which are the most common type and readily visible on x-rays due to their high calcium content, uric acid stones lack this calcium component making them less detectable with standard imaging techniques. Cystine stones also have some degree of radio-lucency but not to the same extent as uric acid stones, while struvite and calcium phosphate stones are typically more radiopaque and easier to identify on x-rays. The diagnosis of uric acid stones may therefore require advanced imaging modalities such as computed tomography (CT) scans, which are considered the gold-standard diagnostic test for all types of kidney stones.