Can a Carbonated Lemon Drink Reduce Extracardiac Activity in Myocardial Perfusion Imaging?

Myocardial perfusion imaging (MPI) provides physiologic and functional information about the heart muscle and its blood flow. Extracardiac radioactivity can interfere with visualization of the inferior wall of the myocardium, leading to poor-quality images, difficulties in interpretation, and delays in routine practice. This study aimed to identify the efficiency of having the patient consume a carbonated lemon drink to minimize the extracardiac radioactivity of Tc-sestamibi in comparison to Tc-tetrofosmin during MPI. This was a retrospective study that recruited 158 patients with known or suspected coronary artery disease referred to undergo Tc-sestamibi or Tc-tetrofosmin rest/stress single-day MPI. The patients were divided into 2 groups of mixed sexes and different ages. The first group comprised 78 patients injected with Tc-sestamibi, and the second group comprised 80 patients injected with Tc-tetrofosmin. For both groups, the patients drank 30 mL of fresh lemon juice diluted with 150 mL of soda water, and then we gave the patients about 100 mL of straight soda water, before imaging for both the rest and the stress phases. Generally, in both groups, the Tc-tetrofosmin produced a good-quality image in comparison with the Tc-sestamibi. The mean rank of the total score for Tc-tetrofosmin (62.75) was less than that for Tc-sestamibi (96.68), and this difference was highly statistically significant ( = 0.000). There were statistically significant differences in the ratios and mean ranks for both groups in favor of Tc-tetrofosmin in patients having coronary artery disease. The use of a carbonated lemon drink minimizes extracardiac activity from both Tc-labeled MPI radiopharmaceuticals. This finding was more statistically significant for Tc-tetrofosmin MPI, providing better image quality and earlier imaging in both the rest and the stress phases because of faster hepatobiliary clearance.