Bone and Cardiac Imaging
The recommended adult doses of Technetium Tc 99m Pyrophosphate Injection are:
Indication
Doses as
Technetium Tc 99
Fraction of
Vial Contents Required
Skeletal Imaging
185 to 555 megabecquerels
(5 to 15 mCi)
0.07 to 0.91
Cardiac Imaging
370 to 555 megabecquerels
(10 to 15 mCi)
0.26 to 0.45
Technetium Tc 99m Pyrophosphate Injection is injected intravenously over a 10- to 20-second period. For optimal results, bone imaging should be done one to six hours following administration. Cardiac imaging should be done 60 to 90 minutes following administration. The acute myocardial infarct can be visualized from 24 hours to nine days following onset of symptoms, with maximum localization at 48 to 72 hours. Cardiac imaging should be done with a gamma scintillation camera. It is recommended that images be made of the anterior, left anterior oblique and left lateral projections.
The patient dose should be measured by a suitable radioactivity calibration system immediately prior to administration. It is also recommended that the radiochemical purity be checked prior to administration.
Blood Pool Imaging
The recommended adult dose of Technescan PYP is one-third (0.33) to the entire vial contents, followed by 555 to 740 megabecquerels (15 to 20 millicuries) of sodium pertechnetate Tc 99m. Cardiac imaging should be done 10 minutes following the administration of sodium pertechnetate Tc 99m (in vivo method) or Tc 99m labeled red blood cells (modified in vivo/in vitro method) utilizing a scintillation camera interfaced to an electrocardiographic gating device.
In Vivo Method: Technescan PYP is reconstituted with sterile, non-pyrogenic normal saline containing no preservatives. The patient dose is administered intravenously 15 to 30 minutes prior to the intravenous administration of 555 to 740 megabecquerels (15 to 20 millicuries) of sodium pertechnetate Tc 99m. Technescan PYP should be injected by direct venipuncture. Heparinized catheter systems should be avoided.
Modified In Vivo/In Vitro Method Using Acid-Citrate-Dextrose (ACD): Technescan PYP is reconstituted with sterile, non-pyrogenic normal saline containing no preservatives, and the patient dose is administered intravenously. An intravenous line containing a 3-way stopcock is inserted in a large peripheral vein and kept patent with a continuous drip of sterile, non-pyrogenic normal saline containing no preservatives. Thirty minutes after Technescan PYP injection, the infusion line and stopcock are cleared by withdrawing and discarding approximately 5 milliliters of whole blood. Immediately following, approximately 5 milliliters of whole blood are withdrawn into a syringe containing 1 milliliter preservative-free acid-citrate-dextrose (ACD) and 555 to 740 megabecquerels (15 to 20 millicuries) of sodium pertechnetate Tc 99m. The stopcock is then turned, residual blood is flushed from the intravenous line, and the normal saline flow is readjusted. The syringe is gently rotated to mix and allowed to incubate at room temperature for 10 minutes prior to injection via the 3-way stopcock.
Modified In Vivo/In Vitro Method Using Heparin: Technescan PYP is reconstituted with sterile, non-pyrogenic normal saline containing no preservatives, and the patient dose is administered intravenously. An infusion set fitted with a 3-way stopcock is placed in a large peripheral vein, and the intravenous line is heparinized with a saline solution containing 5 to 10 units preservative-free heparin per milliliter. Thirty minutes after Technescan PYP injection, 3 milliliters of blood are withdrawn into a syringe containing 555 to 740 megabecquerels (15 to 20 millicuries) of sodium pertechnetate Tc 99m. Anticoagulation of the blood is provided by residual heparin in the intravenous line. The syringe is gently rotated to mix and allowed to incubate at room temperature for 10 minutes prior to injection via the 3-way stopcock.
Parenteral drug products should be visually inspected for particulate matter and discoloration prior to administration whenever solution and container permit. Do not use if contents are turbid.
