Department of Nuclear Medicine & PET, Postgraduate Institute of Medical Education and Research, Chandigarh, 160 012, India.
J Nucl Cardiol. 2011 Oct;18(5):926-36. doi: 10.1007/s12350-011-9422-8. Epub 2011 Jul 6.
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.
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".
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.
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.
氟代脱氧葡萄糖（FDG）可用于可视化冠状动脉粥样硬化斑块中的炎症，如果心肌 FDG 摄取得到充分抑制。为了抑制心肌 FDG 摄取而长时间禁食并不一致。我们评估了使用低碳水化合物高脂肪蛋白质允许（LCHFPP）饮食来持续抑制心肌 FDG 摄取的可行性。
这是一项前瞻性研究。50 例患者纳入禁食组（>12 小时禁食），60 例患者纳入 LCHFPP 饮食组。禁食组无特殊饮食准备。LCHFPP 饮食组患者要求在研究前一晚和 4 小时前食用 LCHFPP 饮食。在最大强度投影图像上进行心肌 FDG 摄取的视觉分析。使用 CT 图像进行定位，在相应的 PET 图像上评估左冠状动脉可能的 FDG 摄取的可描绘性，并将研究分类为“可解释”或“不可解释”。
纳入 LCHFPP 饮食组 60 例（平均年龄 47 岁）和禁食组 50 例（平均年龄 49.9 岁）。患者均无已知糖尿病。平均血糖水平为 96mg/dL。48 例患者按方案摄入 LCHFPP 饮食。12 例仅在研究前一晚摄入 LCHFPP 饮食（不遵守）。在遵守饮食的患者中，平均禁食时间为 5.9±0.9 小时，在禁食组为 14.6 小时。在 LCHFPP 饮食组中，31 例患者的心肌 FDG 摄取被分类为完全抑制；15 例摄取最小；8 例为中度不均匀摄取；6 例为均匀强烈摄取。60 例患者中有 54 例有可解释的研究。排除不遵守的患者后，84%的患者有明显的 FDG 摄取抑制，94%的研究可解释。在禁食组中，16 例患者完全抑制心肌 FDG 摄取，8 例摄取最小，15 例中度不均匀摄取，11 例均匀强烈摄取。27 例（54%）患者有可解释的研究。
使用 LCHFPP 饮食可在大多数患者中实现一致且显著的心肌 FDG 摄取抑制。如果按方案服用 LCHFPP 饮食，可导致一致的心肌 FDG 摄取抑制，从而使几乎所有患者的左冠状动脉炎症得到充分评估。LCHFPP 饮食在抑制心肌 FDG 摄取方面明显优于长时间（>12 小时）禁食方案。
