[Evaluation of a New Protocol for Two-isotope (123)I-BMIPP/(99m)Tc-TF Single Photon Emission Computed Tomography (SPECT) to Detect Myocardial Damage within One Hour].

Objective The present study aimed at establishing a new protocol using both (99m)Tc-Tetrofosmin (TF) and (123)I-BMIPP SPECT to detect myocardial damage within one hour. Methods Initial (123)I-BMIPP SPECT was immediately followed by (99m)Tc-TF SPECT. The influence of (123)I scattered rays on (99m)Tc energy windows set at 15% and 10% were measured using an RH-2 phantom. Participants in the study were patients with heart diseases who had provided written informed consent to undergo the new protocol. The patients maintained the MONZEN position throughout the procedure and an injection syringe was attached to the left arm for (99m)Tc-TF injection during (123)I-BMIPP SPECT. Results & Discussion The phantom study showed only slight (123)I contamination of (99m)Tc at the 10% window setting. The new method separated the (123)I and (99m)Tc energy windows well and neither crosstalk nor scatter correction were needed. Images obtained from dual (simultaneous) acquisition were contaminated, whereas contamination and influence of scattered rays were absent in images obtained by use of the new protocol. These images were thus useful for clinical diagnosis. Conclusion The new protocol is more convenient for patients and might improve the efficiency of detecting myocardial damage.