PET/CT and low carbohydrate diet

Before PET (positron emission tomography)-scanning the body is injected with small amounts of example given fluorodeoxyglucose (FDG), to measure the cells metabolism. Tumour cells and inflammatory cells need more glucose than healthy cells which results in a larger uptake of FDG in these cells. In that way tumours and inflammation can be detected with PET. When examining for example the heart it is desirable to suppress the physiologic uptake of FDG to avoid that abnormalities are missed or that normal uptake is misinterpreted as a change.


Are there scientific studies that support the diet advice to reduce the carbohydrate intake before examination with PET/CT?

Table with identified studies

Table 1. Systematic reviews
* One study is included in both systematic reviews.
18F-FDG PET = 18F-fluorodeoxyglucose positron emission tomography; JMHW = Japanese Ministry of Health and Welfare
Included studies Intervention Outcomes
Atterton-Evans et al 2018* [1]
11 studies on human (1 RCT, the rest were cohort or case control studies) Carbohydrate restricted diet before 18F-FDG PET Visual uptake scales (qualitative), standardised uptake scales (quantitative)
Authors' conclusion:
“A definitive dietary preparation recommendation is not possible based on current evidence, however, scan readability does seem to be improved when preparation includes a reduced carbohydrate intake. More robustly designed studies involving specified cardiac pathologies and ensuring replicable dietary preparations are now needed to identify the ideal dietary macronutrient composition, length of dietary preparation and length of pre-scan fasting required for optimal suppression of myocardial 18F-FDG uptake for cardiac PET scans.”
Tang et al 2016* [2]
5 studies on patients with sarcoidosis (diagnostic cross-sectional or cohort studies) 18F-FDG PET/CT compared to JMHW diagnostic criteria for cardiac sarcoidosis Sensitivity and specificity
Authors' conclusion:
18F-FDG PET/CT plays an integral role in the diagnosis of cardiac sarcoidosis. Diagnostic accuracy is affected by fasting duration and means of cardiomyocyte glucose uptake suppression before scanning.“


  1. Atterton-Evans V, Turner J, Vivanti A, Robertson T. Variances of dietary preparation for suppression of physiological (18)F-FDG myocardial uptake in the presence of cardiac sarcoidosis: A systematic review. J Nucl Cardiol 2018.
  2. Tang R, Wang JT, Wang L, Le K, Huang Y, Hickey AJ, et al. Impact of Patient Preparation on the Diagnostic Performance of 18F-FDG PET in Cardiac Sarcoidosis: A Systematic Review and Meta-analysis. Clin Nucl Med 2016;41:e327-39.

SBU Enquiry Service consists of systematic literature searches to highlight studies that can address questions received by the SBU Enquiry Service from Swedish healthcare or social service providers. Relevant references are compiled by an SBU staff member, in consultation with an external expert when needed. The quality of the studies identified is not systematically reviewed.

Published: 1/15/2019
Contact SBU:
Report no: ut201901
Registration no: SBU 2018/639

Literature search

Project group

Miriam Entesarian Matsson, Sara Fundell and Jenny Stenman at SBU.

Page published