Cedars-Sinai Medical Center, Los Angeles, California.
BHF Centre for Cardiovascular Science, Clinical Research Imaging Centre, Edinburgh Heart Centre, University of Edinburgh, Edinburgh, United Kingdom; and.
J Nucl Med. 2019 Apr;60(4):530-535. doi: 10.2967/jnumed.118.217885. Epub 2018 Sep 13.
Coronary F-sodium fluoride (F-NaF) PET identifies ruptured plaques in patients with recent myocardial infarction and localizes to atherosclerotic lesions with active calcification. Most studies to date have performed the PET acquisition 1 h after injection. Although qualitative and semiquantitative analysis is feasible with 1-h images, residual blood-pool activity often makes it difficult to discriminate plaques with F-NaF uptake from noise. We aimed to assess whether delayed PET performed 3 h after injection improves image quality and uptake measurements. Twenty patients (67 ± 7 y old, 55% male) with stable coronary artery disease underwent coronary CT angiography (CTA) and PET/CT both 1 h and 3 h after the injection of 266.2 ± 13.3 MBq of F-NaF. We compared the visual pattern of coronary uptake, maximal background (blood pool) activity, noise, SUV, corrected SUV (cSUV), and target-to-background (TBR) ratio in lesions defined by CTA on 1-h versus 3-h F-NaF PET. On 1-h PET, 26 CTA lesions with F-NaF PET uptake were identified in 12 (60%) patients. On 3-h PET, we detected F-NaF PET uptake in 7 lesions that were not identified on 1-h PET. The median cSUV and TBRs of these lesions were 0.48 (interquartile range [IQR], 0.44-0.51) and 1.45 (IQR, 1.39-1.52), respectively, compared with -0.01 (IQR, -0.03-0.001) and 0.95 (IQR, 0.90-0.98), respectively, on 1-h PET (both < 0.001). Across the entire cohort, 3-h PET SUV was similar to 1-h PET measurements (1.63 [IQR, 1.37-1.98] vs. 1.55 [IQR, 1.43-1.89], = 0.30), and the background activity was lower (0.71 [IQR, 0.65-0.81] vs. 1.24 [IQR, 1.05-1.31], < 0.001). On 3-h PET, TBR, cSUV, and noise were significantly higher (respectively: 2.30 [IQR, 1.70-2.68] vs. 1.28 [IQR, 0.98-1.56], < 0.001; 0.38 [IQR, 0.27-0.70] vs. 0.90 [IQR, 0.64-1.17], < 0.001; and 0.10 [IQR, 0.09-0.12] vs. 0.07 [IQR, 0.06-0.09], = 0.02). Median cSUV and TBR increased by 92% (range, 33%-225%) and 80% (range, 20%-177%), respectively. Blood-pool activity decreases on delayed imaging, facilitating the assessment of F-NaF uptake in coronary plaques. Median TBR increases by 80%, leading to the detection of more plaques with significant uptake than are detected using the standard 1-h protocol. A greater than 1-h delay may improve the detection of F-NaF uptake in coronary artery plaques.
冠状动脉 F-氟化钠（F-NaF）PET 可识别近期心肌梗死患者的破裂斑块，并定位到有活性钙化的动脉粥样硬化病变。迄今为止，大多数研究都是在注射后 1 小时进行 PET 采集。尽管 1 小时图像可进行定性和半定量分析，但残留的血池活性常常使 F-NaF 摄取的斑块与噪声难以区分。我们旨在评估注射后 3 小时进行延迟 PET 是否可以改善图像质量和摄取测量。
20 名患有稳定型冠状动脉疾病的患者（67±7 岁，55%为男性）在注射 266.2±13.3 MBq F-NaF 后 1 小时和 3 小时分别进行了冠状动脉 CT 血管造影（CTA）和 PET/CT 检查。我们比较了 CTA 定义的病变在 1 小时和 3 小时 F-NaF PET 上的冠状动脉摄取、最大背景（血池）活性、噪声、SUV、校正 SUV（cSUV）和靶/背景（TBR）比值的视觉模式。
在 1 小时 PET 上，在 12 名患者（60%）中识别出 26 个具有 F-NaF PET 摄取的 CTA 病变。在 3 小时 PET 上，我们在 1 小时 PET 上未识别到的 7 个病变中检测到 F-NaF PET 摄取。这些病变的中位数 cSUV 和 TBR 分别为 0.48（四分位距[IQR]，0.44-0.51）和 1.45（IQR，1.39-1.52），而在 1 小时 PET 上分别为 0.01（IQR，0.03-0.001）和 0.95（IQR，0.90-0.98），差异均有统计学意义（均<0.001）。在整个队列中，3 小时 PET SUV 与 1 小时 PET 测量值相似（1.63[IQR，1.37-1.98]比 1.55[IQR，1.43-1.89]， = 0.30），背景活性较低（0.71[IQR，0.65-0.81]比 1.24[IQR，1.05-1.31]， < 0.001）。在 3 小时 PET 上，TBR、cSUV 和噪声均显著升高（分别为：2.30[IQR，1.70-2.68]比 1.28[IQR，0.98-1.56]， < 0.001；0.38[IQR，0.27-0.70]比 0.90[IQR，0.64-1.17]， < 0.001；0.10[IQR，0.09-0.12]比 0.07[IQR，0.06-0.09]， = 0.02）。中位数 cSUV 和 TBR 分别增加了 92%（范围，33%-225%）和 80%（范围，20%-177%）。延迟成像时血池活性降低，有利于评估冠状动脉斑块中的 F-NaF 摄取。中位数 TBR 增加 80%，导致比标准 1 小时方案检测到更多具有显著摄取的斑块。延迟时间超过 1 小时可能会提高冠状动脉斑块中 F-NaF 摄取的检测率。
