Which type of kidney stone is always radiolucent?

Uric acid stones are always radiolucent, meaning they do not appear on standard X-rays. This characteristic is crucial because it helps in the diagnosis and management of kidney stones. Uric acid stones form in acidic urine and are more likely to develop in individuals with conditions such as gout or those undergoing chemotherapy.

The radiolucent nature of uric acid stones can sometimes complicate diagnosis since routine imaging techniques like X-rays may not reveal them. Instead, other imaging modalities such as ultrasound or CT scans may be required to identify these stones effectively.

In contrast, other types of stones such as struvite (formed in alkaline urine and associated with infections), calcium (such as calcium oxalate or calcium phosphate), and cystine stones can be radiopaque, meaning they can be seen on X-rays. This differentiation in imaging properties helps clinicians determine the type of stone and its underlying causes, thereby guiding appropriate treatment strategies.