Presentation
Acutely progressive CKD stage IV, question of renal artery stenosis.
Patient Data
Baseline (pre captopril) study
Normal bilateral renal perfusion and cortical uptake. Radiotracer appears in the calyx by 90 seconds bilaterally. Clearance of radiotracer from the upper urinary tract with persistent cortical retention at the end of 20 minutes study. Time to peak is approximate 5 minutes in both kidneys.
Post captopril study
Normal bilateral renal perfusion and cortical uptake. Radiotracer appears in the calyx by 90 seconds bilaterally. Clearance of radiotracer from the upper urinary tract with persistent cortical retention at the end of 45 minutes study. Time to peak is approximate 3 minutes on the left and 4 minutes on the right.
Both the baseline study and post captopril study demonstrate a normal Type 0 renogram with 20-minute/max ratio not significantly different between the two studies.
The differential renal function at 2-3 minutes is 49% on the left and 51% on the right and baseline and 50% bilaterally at the post captopril study.
Overall impression:
No scintigraphic evidence of renal artery stenosis.
Case Discussion
The technique was as follows:
- Tc99m-MAG3 was administered via IV cannula for baseline study.
- 25mg of catopril given.
- IV Tc99m-MAG was then administered 1 hour post catopril.
- Dynamic and planar imaging were performed.
Case of a normal MAG3 captopril study, no evidence of stenosis.