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Updated: May 31, 2026
High-Resolution Cardiac Positron Emission Tomography/Computed Tomography for Small Animals
Published on: December 16, 2022
Utility of high fat and low carbohydrate diet in suppressing myocardial FDG uptake
Chidambaram Natrajan Balasubramanian Harisankar1, Bhagwant Rai Mittal, Kanhaiya Lal Agrawal
1Department of Nuclear Medicine & PET, Postgraduate Institute of Medical Education and Research, Chandigarh, 160 012, India.
Insights
A low carbohydrate high fat protein permitted (LCHFPP) diet effectively suppresses myocardial FDG uptake for better coronary artery imaging. This diet is more effective than prolonged fasting for visualizing inflammation in atherosclerotic plaques.
Area of Science:
- Cardiovascular Imaging
- Nuclear Medicine
- Dietary Interventions
Background:
- Fluorodeoxyglucose (FDG) Positron Emission Tomography (PET) can visualize inflammation in atherosclerotic plaques.
- Adequate suppression of myocardial FDG uptake is crucial for accurate coronary artery imaging.
- Prolonged fasting is an inconsistent method for myocardial FDG uptake suppression.
Purpose of the Study:
- To evaluate the feasibility of consistently suppressing myocardial FDG uptake using a low carbohydrate high fat protein permitted (LCHFPP) diet.
- To compare the efficacy of the LCHFPP diet with prolonged fasting for myocardial FDG uptake suppression.
Main Methods:
- Prospective study involving 110 patients divided into a fasting group (>12 hours) and an LCHFPP diet group.
- LCHFPP diet group consumed the diet the night before and 4 hours prior to the PET scan.
- Myocardial FDG uptake was visually assessed, and studies were classified as interpretable or not interpretable.
Main Results:
- The LCHFPP diet group showed significantly better FDG uptake suppression compared to the fasting group.
- In the LCHFPP diet group, 94% of studies were interpretable for coronary artery inflammation assessment when compliant patients were considered.
- The fasting group had only 54% interpretable studies for coronary artery inflammation.
Conclusions:
- The LCHFPP diet consistently and significantly suppresses myocardial FDG uptake, enabling adequate evaluation of left coronary artery inflammation.
- The LCHFPP diet is a more efficacious method for myocardial FDG uptake suppression than prolonged fasting.
- Adherence to the LCHFPP diet protocol is key to achieving optimal results for coronary artery imaging.
Introduction:
Fluoro-deoxy-glucose (FDG) can be used to visualize inflammation in atherosclerotic plaques in coronary arteries, if myocardial FDG uptake is adequately suppressed. Prolonged fasting for suppressing myocardial FDG uptake is inconsistent. We evaluated the feasibility to consistently suppress myocardial FDG uptake with a low carbohydrate high fat protein permitted (LCHFPP) diet.
Materials And Methods:
This was a prospective study. 50 patients were included in fasting group (>12 hours fasting) and 60 patients were included into LCHFPP diet. Fasting group had no special dietary preparation. Patients in LCHFPP diet group were asked to consume LCHFPP diet the night before and 4 hours prior to the study. Visual analysis of myocardial FDG uptake was done on maximum intensity projection image. Using CT images for localization, the ability to delineate possible FDG uptake in the left coronary artery was assessed in the corresponding PET image and the studies were classified as "interpretable" or "Not interpretable".
Results:
60 patients (mean age 47 years) from LCHFPP diet group and 50 patients (mean age 49.9 years) from fasting group were included. None of the patients were known diabetics. The mean blood glucose level was 96 mg/dL. Forty-eight patients had consumed LCHFPP diet as per protocol. Twelve had consumed LCHFPP diet only on the night before the study (non-compliant). The average duration of fasting in compliant patients was 5.9 ± 0.9 hours in the diet group and 14.6 hours in fasting group. In LCHFPP diet group, the myocardial FDG uptake was classified as complete suppression in 31; minimal uptake in 15; moderate inhomogenous uptake in 8 and homogenous intense uptake in 6 patients. Fifty-four of the 60 patients had interpretable study. When non-compliant patients were excluded, 84% of the patients had significant FDG uptake suppression and 94% of the studies were classified as interpretable. In the fasting group, complete myocardial suppression of FDG uptake was noticed in 16; minimal in 8; moderate inhomogenous in 15; and homogenous intense in 11 patients. 27 patients (54%) had interpretable study.
Conclusion:
Consistent and significant myocardial FDG uptake suppression is possible in most patients using LCHFPP diet. The LCHFPP diet, if taken as per protocol, leads to consistent myocardial FDG uptake suppression to allow for adequate evaluation of the left coronary artery inflammation in nearly all the patients. LCHFPP diet is also significantly more efficacious than prolonged (>12 hours) fasting protocol in suppressing myocardial FDG uptake.
