BACKGROUND AND OBJECTIVE: Interfering sub-diaphragmatic activity in the liver, bile ducts and intestines is one of the complications of myocardial perfusion imaging in the diagnosis of coronary artery disease. The aim of this study was to compare the effectiveness of water, milk and natural lemon juice on liver secretion and reduction of ^99mTc-sestamibi radiopharmaceutical radiation in this type of imaging. 
METHODS:This clinical study was performed on 100 female patients referred to the Shahid Beheshti Hospital in Babol for myocardial perfusion imaging using SPECT method. These patients were randomly divided into 4 groups: patients receiving no drink (group 1), patients receiving 250 ml water (group 2), patients receiving 250 ml high-fat milk (group 3), and patients receiving 250 ml diluted lemon juice was (group 4). After measuring heart and liver absorption, their ratio was calculated (heart/liver). The rate of reduction of interfering sub-diaphragmatic activity after the use of these drinks in different groups was evaluated based on visual and semi-quantitative assessments.
Finding:The four studied groups did not differ significantly in terms of age, weight, and body mass index. The H/L ratio in group 1 was 0.13±0.038, in the group 2 was 0.15±0.039, in the group 3 was 0.17±0.055 and in the group 4 was 0.15 ± 0.039. Statistical analysis showed that interfering sub-diaphragmatic activity was only significant in group 3 in comparison with group 1 (p=0.027). In addition, based on visual and semi-quantitative assessments of raw data, only in group 3, 18 out of 25 patients had less interfering sub-diaphragmatic activity, which was significant compared to group 1 (p=0.001).
CONCLUSION: The results of the study showed that drinking at least 250 ml high-fat milk can reduce the interfering sub-diaphragmatic activity.