Imaging Case of the Week 67

The following coronal CT scan image is from a 30 year old woman whose presenting problem has been severe right sided loin to groin pain. What can you see?

coronal CT

click to enlarge

[peekaboo_link name=”Answer”]Answer[/peekaboo_link] [peekaboo_content name=”Answer”]

The CT slice shows a calculus in the urethra, about 6 mm in size when measured. Other slices showed mild right sided hydronephrosis with perinephric stranding, indicating the passage of a right ureteric stone that is now in the urethra.

The patient uneventfully passed the stone after a few hours.

Urethral calculi are rare and can be of 2 types:

  1. Primary calculi that form secondary to the urethral stricture or diverticulum. They are predominantly made up of phosphate that is formed in infected urine.
  2. Secondary calculi originate elsewhere in the urinary tract and migrate to the urethra. They mostly contain calcium oxalate.