- Risk factors: urinary stasis (voiding dysfunction i.e., urethral stricture, benign prostatic hyperplasia, bladder neck contracture, neurogenic bladder), infection, bladder diverticula, foreign body (Foley catheter balloon, suture material, etc)
- Common compositions: uric acid, ammonium urate, calcium oxalate
- Uric acid stones predominate in a setting of bladder outlet obstruction
- Magnesium ammonium phosphate and apatite stones predominate in a setting of urinary tract infection (UTI)
- Patient presentation: hematuria, suprapubic pain, interruption of urine stream
- If sufficiently calcified, bladder stones may be visible on radiography
- Tends to locate in the midline when the patient is supine
- If calcification is located laterally, think of a stone in the diverticulum or ureterocele
- Key to confirm that the abnormality is a stone = mobility (either on radiography or ultrasound)
1. Zagoria RJ. Genitourinary Radiology: the Requisites, 2004.
2. Tanagho EA, McAninch JW. Smith's General Urology, 2004.