[A comparative study of imaging of myocardial perfusion with 201Tl-SPECT and 13NH3-PET: visual and quantitative evaluation].

UNLABELLED

We compared the results of visual and quantitative evaluation of imaging of myocardial perfusion with 201Tl-SPECT and 13NH3-PET in the 7 non-myocardial infarction (non-MI) and 42 myocardial infarction (MI) patients. On the 201Tl-SPECT and 13NH3-PET imaging, the degree of accumulation of each radioisotope (RI) was visually classified into four grades of defect score. The percentage of uptake was also quantitatively evaluated.

RESULTS

In the 7 non-MI patients, NH3% uptake in the lateral wall was significantly lower than in the septum, and in the lateral wall NH3% uptake was significantly lower than Tl% uptake. For the 42 MI patients, segmental defect scores (DS) on 201Tl-SPECT were compared with those on 13NH3-PET, and a high degree of concordance in DS was found for all territories of the left ventricle, antero-septum MI and inferior MI territories. Average Tl% uptake/NH3% uptake was near 1, a highly positive correlation was found between Tl% uptake and NH3% uptake in all territories of the left ventricle and antero-septum MI territories, and Tl% uptake/NH3% uptake was larger than 1, but, a significant positive correlation existed between Tl% uptake and NH3% uptake in the territory with inferior MI.

CONCLUSION

These findings indicate that results of 201Tl-SPECT imaging were similar to those of 13NH3-PET in evaluation of myocardial perfusion in the antero-septum and inferior. However, a difference in distribution was observed between 201TlCl and 13NH3 in the lateral wall, indicating that particular attention should be paid to the results of imaging of myocardial perfusion in the lateral wall.