a 1-week extension of a ketogenic diet provides a further decrease in myocardial 18 f-fdg uptake and a high detectability of myocarditis with fdg-pet

Short periods of fasting and/or low-carbohydrate diet have been proven beneficial for decreasing the myocardial uptake of 18f-fluorodeoxyglucose (18f-fdg) and enhancing the detection of inflammatory heart diseases by 18f-fdg positron emission tomography (pet). this study aimed at determining whether this benefit is increased when a low-carbohydrate ketogenic diet is prolonged up to 7 days. wistar rats underwent serial 18f-fdg-pet imaging after an 18-hour fasting period and after 2, 4 and 7 days of a ketogenic diet (3% carbohydrate) and they were compared to rats submitted to the same protocol but with normal diet (44% carbohydrate). the 18f-fdg-pet/ketogenic protocol was also applied in rats with immune myocarditis (injection of porcine cardiac myosin). the 7-day ketogenic diet was associated with (1) a sustained increase in circulating ketone bodies at an equivalent level to that reached after 18-hour fasting, (2) a gradual decrease in 18f-fdg uptake within normal myocardium reaching a lower level compared to fasting at the 7th day (myocardium-to-blood ratios: 1.68 ± 1.02 vs 3.25 ± 1.40, p < .05) and (3) a high 18f-fdg-pet detectability of myocarditis areas. one-week extension of a ketogenic diet provides a further decrease in the 18f-fdg uptake of normal myocardium and a high detectability of inflammatory areas.