O reilly curves used in renal dynamic scan

1. O’REILLY’S CURVES

2. • Functional upper tract assessment.
• Attaching a gamma-emitting nuclide to a molecule that is excreted
and concentrated in urine.
• 99mTc-EC (Ethylene dicystine)
RENOGRAPHY

3. • Differentiating patients with equivocal obstruction of upper urinary
tract.
• If a system is genuinely obstructed  flow is impaired at high and low
urinary flow rates.
• Slow elimination is due to urinary stasis  responds to increase in
the urinary flow rate.
• Increased flow is achieved by a loop diuretic.
DIURESIS RENOGRAPHY

5. O’Reilly PH, Testa HJ, Lawson RS et al. Diuresis renography in equivocal urinary tract obstruction. Br J Urol 1978;50:76-80.

6. • Patient should be well hydrated.
• Bladder should be empty.
• Radiopharmaceutical in injected IV.
• Dynamic images are obtained at 15sec/frame.
• Static images at 30min and 4 hrs.
• Furosemide injected as per protocol (F+20, F-15, F0-children)
• Patient should void post procedure.
PROTOCOL

7. • Region of Interest (ROI) are drawn over both the kidneys and bladder.
• The number of counts occurring in each ROI is computed for each
time frame and the counts plotted against time.
• Background count is subtracted.
• Resultant “Time-activity curve”

8. NORMAL RENOGRAM CURVE

9. FACTORS INFLUENCING RENOGRAM CURVE
Poor renal function
Poor hydration
pre-procedure
hydration
Massively dilated
collecting
system Diuretic Bladder effect 
voiding pre-
procedure OR
indwelling catheter

10. • Original description- inject diuretic 20mins after radiopharmaceutical- F+20.
• Enables upper tract to be studied without manipulation.
• If rapid washout is observed, diuretic injection may be considered
unnecessary, reducing small inconvenience to patient.
• Classic response curves are described on the F+20 protocol.
TIMING OF DIURETIC

11. • If maximum diuresis is required from the outset- diuretic should be
injected 15 mins prior to radiopharmaceutical- F-15
• Reduces the equivocal rate from 15-17% (F+20) to 3%(F-15)*
• Simultaneous injection of tracer and diuretic-F0
• Alternative to F-15 which is more convenient.
* O’Reilly PH. Diuresis renography. Recent advances an recommended protocols. Br J Urol 1992; 69:113-20.

12. TYPES OF CURVES

13. TYPE 1-NORMAL
Normal washout is
obtained at resting
flow rates before the
diuretic is given.

14. TYPE 2-OBSTRUCTED
• Curve continues to rise
despite diuretic
administration.
• Possible reasons of false
positive report should be
ruled out.

15. TYPE 3A-HYPOTONIC
• Non-obstructive response
• Initially obstructive rising curve
falls on injection of diuretic.
• Indicates that the dilatation is
because of stasis rather than
obstruction.

16. TYPE 3B-EQUIVOCAL
• The initial obstructive rising
curve on injection of diuretic
neither washes out briskly nor
continues to rise.
• Primary indication for F-15
protocol.
• If there has been adequate
hydration and the SKGFR is >16
ml/min, then the equivocal
response probably indicates
subtotal obstruction.

17. TYPE 4-DELAYED
DECOMPENSATION
• Delayed double peak pattern.
• Initial washout response to the
diuretic is good, but then the curve
flattens or even starts to rise.
• During the resting and early diuretic
phases, the flow can be transported
by the pelviureteric junction.
• Eventually, the flow rate reaches a
level at which the system under
stress can no longer transmit the
urine load.
• It decompensates and further
dilatation occurs.
• Can be seen in VUR.
• Indication of F-15 protocol

18. 3%
SKGFR
<16 perfusion
pressure flow
studies
> 16 observe
15-17%

22. THANK YOU