Which pair of stone types are typically radiopaque on KUB radiographs?

Which pair of stone types are typically radiopaque on KUB radiographs?

• A. Calcium oxalate and struvite
• B. Calcium oxalate and uric acid
• C. Uric acid and cystine
• D. Struvite and uric acid

Answer: (A)

The key idea is radiopacity on a plain KUB X-ray, which depends on stone composition. Calcium-containing stones are dense and show up well on X-ray, making them radiopaque. Struvite stones, made of magnesium ammonium phosphate, share this radiopacity as well. In contrast, uric acid stones are typically radiolucent on plain films and may be missed without CT or ultrasound. Cystine stones are generally radiopaque too, but calcium oxalate and struvite are the classic, consistently radiopaque pair. So, calcium oxalate and struvite are typically visible on a KUB.

The key idea is radiopacity on a plain KUB X-ray, which depends on stone composition. Calcium-containing stones are dense and show up well on X-ray, making them radiopaque. Struvite stones, made of magnesium ammonium phosphate, share this radiopacity as well. In contrast, uric acid stones are typically radiolucent on plain films and may be missed without CT or ultrasound. Cystine stones are generally radiopaque too, but calcium oxalate and struvite are the classic, consistently radiopaque pair. So, calcium oxalate and struvite are typically visible on a KUB.