Tc-99m pertechnetate

Last revised by Joshua Yap on 01 Jan 2023

Tc-99m pertechnetate (Na+ 99mTc O4-) is one of the technetium radiopharmaceuticals used in imaging of thyroid, colon, bladder and stomach.

Technetium (99mTc) has eight oxidation states 6, from -1 to +7; specifically, the oxidation state of technetium in the pertechnetate anion (99mTcO4-) is +7. The pertechnetate anion is, among the chemical species of technetium, the most stable in aqueous solution 6,7

  • photon energy: 140 keV

  • protons: 43 (i.e. atomic number)

  • physical half-life: 6 hours

  • biological half-life: ~1 day

  • 4.0 < pH < 8.0 6,7

  • radiochemical purity: >95%

  • molecular geometry (pertechnetate anion): tetrahedral 6,7

  • normal distribution: stomach, thyroid, salivary glands, testes

  • excretion: renal, GI

  • target organs: thyroid, colon, bladder, stomach, testicular (rarely performed)

  • compounding of technetium radiopharmaceuticals using technetium pertechnetate may be done under room temperature or heating 9

Pediatric doses have been derived from various sources; a true international consensus remains a work in progress.

  • Meckel diverticulum

    • adult dose: 370 MBq (10 mCi) IV

    • pediatric dose: 1.85 MBq/kg (0.05 mCi/kg) 5

      • minimum 9.25 MBq (0.25 mCi) 5

    • time of imaging: immediate (1 frame/s x 60 s then q 5-10 min x 1 hr)

  • parathyroid subtraction

    • adult dose: 37-74 MBq (1-2 mCi) IV

    • time of imaging: image for 15 minutes after Tl-201 injection and imaging

  • testicular

    • adult dose: 370 MBq (10 mCi) IV

    • pediatric dose: pending mCi/kg

      • minimum 185 MBq (5 mCi) 3

    • time of imaging: 60 second flow study with delayed static images

  • thyroid

    • adult dose: 37-370 MBq (1-10 mCi) IV

      • usually 111-185 MBq (3-5 mCi)

    • time of imaging: 20 minutes

Technetium was discovered in 1937 by C Perrier and Emilio Segre at Palermo University. They managed to isolate technetium-97 from a sample of molybdenum irradiated with deuterons in the cyclotron of the University of Berkeley 8.

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Cases and figures

  • Case 1: thyroid nodule
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  • Case 2: Meckel scan
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  • Case 3: Graves disease
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  • Case 4: Graves disease
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  • Case 5: Graves disease
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