Presentation
Left renal colic.
Patient Data
Age: 45 years
Gender: Male
From the case:
Obstructive uropathy with delayed nephrogram
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Leftt kidney is moderately enlarged and shows:
- mild to moderate hydronephrosis with ureteral dilatation up to the pelvic region where there is an ureteral stone obstructing the ureteral lumen
- delayed cortical nephrogram well-demonstrated on excretory phase
Right kidney shows normal appearance with no renal or ureteral stone. Absent cortical nephrogram on excretory phase.
Diffuse hepatic steatosis is noted.
From the case:
Obstructive uropathy with delayed nephrogram
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Annotated images showing the ureteral stone (red arrow) measuring 12 x 6 mm, mean density = 850 HU).
Case Discussion
CT Urogram features of left obstructive uropathy due to ureteral stone with delayed nephrogram.
The delayed nephrogram is characterized by nephrographic enhancement in the delayed or urographic phase which persists for a prolonged period of time.
Obstructive uropathy is the most common cause. Other causes include renal vein thrombosis, renal artery thrombosis and extrinsic compression (Page kidney).