From the Department of Nuclear Medicine, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing.
Clin Nucl Med. 2021 May 1;46(5):369-374. doi: 10.1097/RLU.0000000000003572.
18F-FDG PET myocardial metabolic imaging is used to estimate myocardial viability. However, poor image quality can affect the accurate quantification of viable myocardium. We assessed the feasibility of a rescue protocol that reinjected low-dose 18F-FDG with simultaneous 1 to 2 U of insulin injection and oral administration of 10 g of glucose to improve the image quality of 18F-FDG PET myocardial metabolic imaging.
Fifty-one consecutive patients with poor quality to uninterpretable 18F-FDG PET/CT myocardial metabolic images received the rescue protocol immediately after the initial image acquisition. The postrescue image acquisition was performed 1 hour later. The rescue image quality was compared with the initial image. The qualitative visual estimation of the images was graded as follows: grade 0, homogeneous, minimal uptake; grade 1, predominantly minimal or mild uptake; grade 2, moderate uptake; and grade 3, good uptake. The myocardium-to-blood pool activity ratio (M/B) was measured to assess the image quality quantitatively.
The grades of 0 to 3 were observed in 24 (47%), 27 (53%), 0 (0%), and 0 (0%) patients, respectively, for the initial imaging, and in 0 (0%), 3 (5.9%), 4 (7.8%), and 44 (86.3%) patients for the rescue imaging (P < 0.001). The rescue M/B was significantly higher than the initial M/B (3.4 ± 1.4 vs 1.6 ± 0.6, respectively; P < 0.001).
The rescue protocol successfully and rapidly improved the quality of myocardial 18F-FDG metabolic imaging.
18F-FDG PET 心肌代谢成像用于评估心肌活力。然而，较差的图像质量可能会影响对存活心肌的准确量化。我们评估了一种挽救方案的可行性，该方案通过同时注射 1 至 2 U 胰岛素和口服 10 g 葡萄糖，对低剂量 18F-FDG 进行再注射，以改善 18F-FDG PET 心肌代谢成像的图像质量。
51 例连续患者的 18F-FDG PET/CT 心肌代谢图像质量较差，无法解释，在初始图像采集后立即接受挽救方案。在 1 小时后进行挽救后图像采集。将挽救后的图像质量与初始图像进行比较。图像的定性视觉评估分为以下几个等级：0 级，均匀，最小摄取；1 级，主要为最小或轻度摄取；2 级，中度摄取；3 级，良好摄取。测量心肌与血池的活性比（M/B）以定量评估图像质量。
初始成像时，0 到 3 级分别观察到 24 例（47%）、27 例（53%）、0 例（0%）和 0 例（0%）患者，挽救成像时分别观察到 0 例（0%）、3 例（5.9%）、4 例（7.8%）和 44 例（86.3%）患者（P<0.001）。挽救后 M/B 明显高于初始 M/B（分别为 3.4 ± 1.4 与 1.6 ± 0.6；P<0.001）。
挽救方案成功且快速地改善了心肌 18F-FDG 代谢成像的质量。
