A randomized study of the effect of carbonated water prior to myocardial SPECT

Abstract

Objective In myocardial perfusion single-photon emission computed tomography (SPECT), abdominal activity often interferes with the evaluation of perfusion in the inferior wall, especially after pharmacological stress. In this randomized study, we examined the effect of carbonated water intake versus still water intake on the quality of images obtained during myocardial perfusion images (MPI) studies. Methods A total of 467 MIBI studies were randomized into a carbonated water group and a water group. The presence of intestinal activity adjacent to the inferior wall was evaluated by two observers. Furthermore, a semiquantitative analysis was performed in the adenosine subgroup, using a count ratio of the inferior myocardial wall and adjacent abdominal activity. Results The need for repeated SPECT in the adenosine studies was 5.3 % in the carbonated water group versus 19.4 % in the still water group (p = 0.019). The inferior wall-to-abdomen count ratio was significantly higher in the carbonated water group compared to the still water group (2.11 ± 1.00 vs. 1.72 ± 0.73, p \ 0.001). The effect of carbonated water during rest and after exercise was not significant. Conclusions This randomized study showed that carbonated water significantly reduced the interference of extra-cardiac activity in adenosine SPECT MPI.

A randomized-controlled study of a modified technique to reduce extracardiac activity in myocardial perfusion imaging

“…Thus, the decrease in the MYO:EXC ratio in the delayed stress studies when the combined intervention was given may have been impacted by this natural biologic process. Overall, the MYO:EXC ratio was higher than the recommended target to non-target ratio of 2:1 and was also higher than results from previous studies [3,5,6,12,15,16,20,25]. It is suspected that the differences in imaging times between the studies played a role in the discrepancies of the ratio between studies.…”

“…However, there was a small decrease of 0.03 and 0.02 in the MYO:EXC ratio in the early and delayed stress studies respectively. In a study of the effect of carbonated water prior to myocardial SPECT, Vermeltfoort et al found persistence of interfering infra-cardiac activity in some patients who consumed carbonated water [5].…”

“…Similarly to the current study, patients were asked to drink carbonated water immediately before imaging. It has been suggested that the effect of the carbon dioxide within the carbonated water is transient and decreases after eructation [5,24]. Thus, the decrease in the MYO:EXC ratio in the delayed stress studies when the combined intervention was given may have been impacted by this natural biologic process.…”

“…The normal bio-distribution and mode of clearance of some radiopharmaceuticals used in MPI often leads to interfering extra-cardiac activity which could affect image quality and image interpretation, especially in the region of the inferior wall of the heart [2][3][4]. In addition, the intensity of interfering extra-cardiac activity may lead to repeat imaging [5]. Interfering extra-cardiac activity artifacts are mostly related to activity in the abdomen, arising from the hepatobiliary and gastro-intestinal systems [5,6].…”

“…In addition, the intensity of interfering extra-cardiac activity may lead to repeat imaging [5]. Interfering extra-cardiac activity artifacts are mostly related to activity in the abdomen, arising from the hepatobiliary and gastro-intestinal systems [5,6]. The frequency and intensity of the interfering extra-cardiac activity is affected by the patient's physiological characteristics as well as the type of test performed [2][3][4].…”