5. Radio-nuclides in Nephro-urology
either:
Dynamic: for functional evaluation
Static: for anatomical assessment as pyelonephritis or ischemia
Renal Radiopharmaceuticals:
Tracers for Dynamic Studies:
Tc-99m DTPA (diethylene-triamine-pentaacetate) Cleared by
glomerular filtration
Tc-99m MAG3 (mercaptoacetyltriglycine) Cleared by tubular
secretion
Tracers for Static Studies:
Cleared by tubular secretion, retained in the renal cortex and minimally
excreted in urine
Tc-99m DMSA (dimercaptosuccinic acid).
17. Acute & chronic renal failure
differentiation
Acute renal failure
More or less preserved perfusion
Mild reduction in tracer uptake
Some delay in excretion due to parenchymal retension of the
tracer
Chronic renal failure
Small kidney
Marked reduction in perfusion & tracer uptake
Excretion usually not affected.
21. Obstruction
Obstruction to urine outflow leads to obstructive
uropathy (hydronephrosis, hydroureter) and may
lead to obstructive nephropathy (loss of renal
function)
22. Diuretic Renal Scan
Principle
Tracer pooling in dilated renal pelvis
Lasix induces increased urine flow
If obstructed >>> will not wash out
If dilated, non-obstructed >>> will wash out
Can quantitate rate of washout (T1/2)
23. Diuretic Renal Scan
Indications
Evaluate functional significance of hydronephrosis
Determine need for surgery
Obstructive hydronephrosis - surgical Rx
Non-obstructive hydronephrosis - medical Rx
Monitor effect of therapy
24.
25.
26. Diuretic Renal Scan
Washout (diuretic response)
T1/2
Time required for 50% tracer to leave the dilated unit i.e.
time required for activity to fall to 50% of peak.
27. T1/2
Normal < 10 min
Obstructed > 20 min
Indeterminate 10 - 20 min
Best to obtain own normals for each institution,
depending on protocol used
29. “F minus 15”
Diuretic Renogram
Furosemide (Lasix) injected 15 min before
radiopharmaceutical
Rationale: kidney in maximal diuresis, under maximal
stress
Some equivocals will become clearly positive, some
clearly negative
English, Br JUrol 1987:10-14
Upsdell, Br JUrol 1992:126-132
30. Renovascular Hypertension
Caused by renal hypoperfusion
Atherosclerosis
Fibromuscular dysplasia
Mediated by renin - AT - aldosterone system
Potentially curable by renal revascularization
Captopril Renal Scan (ACEI Renography)
Evaluation of Renovascular Hypertension
31. Off ACEI & ATII receptor blockers x 3-7 days
Off diuretics for 5-7d
No solid food for 4 hrs
Patient well hydrated
ACEI
Captopril 25-50 mg po (crushed), 1 hr pre-scan
ACEI RenographyACEI Renography
Patient PreparationPatient Preparation
41. Renal Transplant
Assessment of the donor.
Assessment of the recipient.
Acute rejection vs ATN.
Vascular : arterial/venous occlusion.
Urological: obstruction, leakage.
DD of urinoma from other collection.
Chronic complications:
Chronic rejection,
Ureteric stricture,
etc……………
55. Tc-99m DMSA
Dimercapto-succinic Acid (3-5 mCi)
Indications
•Tracer of choice for renal parenchymal evaluation
•Not suitable for perfusion or obstruction
•Limited function assessment, but can provide
differential renal function
56. Renal Cortical Scintigraphy
Interpretation
Acute PN
single or multiple “cold” defects
renal contour not distorted
diffuse decreased uptake
diffusely enlarged kidney or focal bulging
Chronic PN
volume loss, cortical thinning
defects with sharp edges
Differentiation of Ac PN vs. Ch PN unreliable
57. DMSA grading for chronic pyelonephritis
Grade 0 : Normal
Grade I : One lesion (or) reduced uptake (< 45%)
Grade II : One lesions + reduced uptake
Grade III : More than one lesion
66. Tc-99m DMSA performed initially in this case with fever and Lt. loin pain.
Follow up scan conducted after one month.
Initial scan Follow up scan @ 1 m
Resolved focal nephritis.
Tc-99m DMSA