A comparison of the clinical relevance of thallium201 and technetium-99m-methoxyisobutyl-isonitrile for the evaluation of myocardial blood flow

  • C.P. Herbst
  • H. Du T. Theron
  • A. Van Aswegen
  • P. H. T. Kleynhans
  • A. C. Otto
  • P. C. Minnaar


Thallium-201 is at present the radiotracer of choice for the clinical evaluation of myocardial blood flow. Although different technetium-99m-isonitrile agents have been synthesised recently, only 99mTc-melhoxyisobutyl-isonitrile (99mTc_MIBI) has proved to hold promise for clinical implementation. The myocardial distribution of 201TI and 99mTc_MIBI was compared in a group of 20 patients, who underwent both 201TI single photon emission computed tomography and 99mTc_MIBI study as well as coronary angiography. The sensitivity for predicting a lesion ranged from 25% to 88% in different areas of the heart and was comparable for the two radiophannaceuticals. The specificity was > 80% tor all regions except the inferior region where a specificily ot 58% obtained by 99mTc-MIBI was better than the low specificity of 17% obtained with 201TI (P< 0,008).


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eISSN: 0256-95749
print ISSN: 2078-5135