Dtpa in pujo

pujo nuclear scan dtpa

1. Renal Nuclear Scan in PUJO Dr G Praveen Chandra

2. DTPA or renal nuclear scan is done to know the precise function

3. Choice of Ix for fn study ………… Diuretic renography MAG-3 B’coz MAG-3 has total tubular secretion so not affected by GFR. In most centers, mercaptoacetyltriglycine (MAG3) has replaced diethylenetriamine pentaacetic acid (DTPA) as the radionuclide of choice

4. MAG3 is both filtered and secreted by the renal tubules, it is more useful in immature or chronically insufficient kidneys than is DTPA .  DTPA is filtered only by the glomerulus and is not actively secreted by tubules

5. There are three parts of a given renal nuclear scan 1. The picturistic / images of the kidneys 2. The graphical representation/curve 3. The numerical values .

6. P icturistic / images of the kidneys …… .. The images given are actually 2 sets of images 1st one represents the perfusion phase and images are taken @ 1 image per sec after injecting contrast. Contrast usually reaches both kidneys simultaneously and within 5 seconds . T hus both kidneys should be seen together after 5 second image.

7. The second set of images are taken @ 1 image per min and represent intra renal transient time and excretion of contrast into PC system and reaching bladder . Usually intra renal transient time (IRT) is less than 4 min so contrast should be seen in PC system by 5 images. Delay in IRT represents obstruction.

8. Rest of the images represent the flow of tracer from PC system to bladder

9. Graphical representation/ curve The curve represents the graphical presentation of the tracer movement across the renal system . The graphs are called O’REILLEY CURVES or time activity curves . Each graph has three lines 1st for aortic trace, 2nd and 3rd for the left and right kidneys.

10. N umerical values ………… The third part of the report is numerical values GFR , IRT and split function .

11. Advances in nuclear medicine methodologies provide the opportunity to assess renal function (GFR , ERPF and MAG3 clearance ) using either plasma sample clearances or camera -based methods . 

12. Plasma sample clearances involve blood sampling.  Camera-based techniques do not require blood or urine samples to measure GFR, ERPF or a MAG3 clearance, but these measurements are not considered to be as accurate as plasma sample techniques and require specialized software

13. According to the timing of Lasix administration …… 3 protocols.  F + 20 - Furosemide is injected 20 minutes after the injection of tracer. F (– 15) - Furosemide is injected 15 minutes prior to the tracer F – 0 - Furosemide is injected at the beginning of the study

14. Renal scan in altered creatinine : Use tubular agents DTPA can be done upto 3.0 mg/dl DMSA and MAG-3 can be done upto 7 mg/dl

15. Less than 15% differential function and less than 10 ml/min of GFR … . “non salvageable” kidney

16. Thank You