Double J Ureteric Catheter (DJ Stent)

1. Definition & Purpose:

A Double J stent is a thin, flexible tube placed in the ureter to ensure urine drainage from the kidney to the bladder.

The term “Double J” refers to the curled (J-shaped) ends — one in the renal pelvis and the other in the bladder, preventing migration.

2. Indications:

● Post-ureteric surgery (e.g., pyeloplasty, ureteric reimplantation)

● Obstructive uropathy (stone, tumor, stricture, edema)

● Post-lithotripsy or ureteroscopy

● Urinary leak prevention (after trauma or

 surgery)

3. Imaging Appearance:

Modality Appearance / Key Points

● X-ray KUB : Radiopaque linear tubular structure with curled ends—one in renal pelvis, one in bladder. Verify both ends visible and in correct position.

● CT (non-contrast) : Clearly visualized as a hyperdense linear structure along ureter’s course. Confirms position and checks for obstruction, migration, or encrustation.

● Ultrasound : Echogenic line with posterior shadow; sometimes only proximal/distal curls seen. Used to detect hydronephrosis or stent-related complications.

● Fluoroscopy Used during insertion/removal—real-time visualization of correct coil placement.

4. Correct Position:

● Proximal end: in renal pelvis or upper calyx.

● Distal end: within bladder lumen.

● Shaft follows ureteric path without kinking.

5. Complications & Radiologic Findings:

Complication, Imaging Findings / Notes

● Migration / Malposition Coil seen outside expected area (e.g., proximal coil in ureter or distal coil in urethra).

● Encrustation / Calcification Irregular hyperdense deposits along stent; better seen on CT or X-ray.

● Fragmentation / Fracture Discontinuity of stent; may cause obstruction.

● Infection / Pyelonephritis. In CT displayed as: perinephric stranding and hydronephrosis.

● Forgotten stent : Encrustation, stone formation and  hydronephrosis.