Improvement of ^99mTc-pyrophosphate scintigraphy in detection of acute myocardial infarction: Combined with ^99mTc-tetrofosmin

[Background] ²⁰¹Tl and ^99mTc-pyrophosphate (PYP) dual scintigraphy is daily used in the detection of acute myocardial infarction (AMI). However, ²⁰¹Tl is not available on emergent situation. We proposed a new method for detection of AMI combined ^99mTc-PYP with ^99mTc-tetrofosmin (TF). [Methods] ^99mTc-PYP (740 MBq) was administered to 25 patients with AMI, and 3.5 hours later, planar imaging (PYP planar) and SPECT were performed (PYP-SPECT). Immediately after cessation of PYP-SPECT, ^99mTc-TF (370-740 MBq) was injected and 5 minutes later SPECT was performed in the same position (TF-SPECT). PYP-SPECT and TF-SPECT were reconstructed in the same geometric status to permit superimpose of PYP-SPECT and TF-SPECT images. Two experts and 2 beginners of nuclear medicine physician interpreted the images in three ways; PYP planar image only, PYP-SPECT, and PYP-SPECT with TF-SPECT. [Results] PYP-SPECT combined with TF-SPECT shows 100% detectability of the AMI lesions, which is significantly higher than other two methods in both experts and beginners. [Conclusion] PYP-SPECT combined with TF-SPECT is a powerful method for detection of AMI.