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This procedure in normally indicated to know whether there is significant obstruction or not which requires intervention in hydronephrotic kidneys (sometimes with associated hydroureters).
Information sought:
1. Functional status of the kidneys.
2. Tubular Transit Status
3. Adequacy of PUJ
Patient scheduling:
Normally there are no constraints for scheduling a renogram procedure.
Study can be scheduled any day and at any time of the day since Tc99m DTPA is easily available. If Tc99m EC is to be used then some labs might prefer to group such patients for a particular day by prior appointment.
Since 1 to 2 hours delayed image will be required often, patient is taken up accordingly so as to complete the delayed image before closing the lab.
Patient Preparation:
Adequate hydration is essential before diuretic renogram. Patients who are kept fasting for other reasons should receive IV fluids accordingly in consultation with the referring physician. For others ensuring that the patient drinks water or other beverages while waiting for the procedure (about 30 minutes before injection) will be more reliable.
Patient Information:
Other relevant investigation reports:
Ultrasound scan report, IVU, MCUG reports if any.
Details on previous surgery if any and Previous renogram images if any.
Reports on Serum Creatinine and Urea levels also if available.
Height, weight, age and sex to be recorded.
Dose preparation:
Tc99m DTPA or Tc99m EC
20 MBq to 370 MBq (0.5 mCi to 10 mCi) depending on the patient.
Activity of the dose for injection should be measured accurately with isotope calibrator and recorded for Clearance Quantitation. In some systems, static acquisition of pre-inj syringe activity may be required .
Patient should be asked to empty the bladder before taken up for scan.
In patients with associated bladder outflow abnormalities and hydroureterosis, continuous bladder drainage via a catheter may be ideal and should be arranged in consultation with the referring physician.
Patient positioning:
Supine in relaxed comfortable position with camera kept beneath.
Patient should be explained on the need for lying still during the scan. Infants and children may need to be restrained gently to avoid unacceptable motion during the scan. Sedation is normally not required for this study. In case if it is needed then oral tichlofos available as “syp.Pedicloryl” can be given orally (25mg/kg for less than 1yr & 400 – 500 mg for 1-5 yrs). Recommended waiting time is 45 min. to get the sedative effect.
Field of view should be verified with a marker to ensure that both kidneys are included.
Occasionally for special reasons patient may be seated erect on a firm stool with the camera behind vertically as a back rest.
Image Acquisition parameters:
Dynamic multi-phase in 64 X 64 matrix size will suffice.
A rapid first pass for the Vascular phase for 1-2 sec per frame X 30 or 60 seconds
Subsequent frames are usually in 15 sec /20 sec/30 sec for a period of 20 min to 45 min.
Radiotracer administration:
IV Bolus without any extravasation is required. A butter fly needle may be retained for purpose of lasix injection later. Some times in the case of infants, it is more convenient to inject the tracer in the dorsal pedal vein on the patient table outside the camera and position immediately after injection and start the acquisition.
Post inj residual activity in the syringe should be measured and recorded.
Lasix injection:
It is important to monitor the tracer uptake by the kidneys and look for the arrival in the collecting system and the bladder area. There are several possibilities, which decide the use of lasix. The dose is 1.0 mg/kg (max 40 mg). In patients with renal failure higher doses (max 80 mg) may be recommended.
(i) No lasix needed:
Normally activity appears in the bladder area at least from one kidney by 6 minutes. There may not be a need for Lasix inj if both kidneys are draining very well and the acquisition can be completed by 20 minutes. If the
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