Cedars-Sinai Medical Center, Los Angeles, California; and.
University of Edinburgh, Edinburgh, United Kingdom.
J Nucl Med. 2016 Jan;57(1):54-9. doi: 10.2967/jnumed.115.162990. Epub 2015 Oct 15.
Ruptured coronary atherosclerotic plaques commonly cause acute myocardial infarction. It has recently been shown that active microcalcification in the coronary arteries, one of the features that characterizes vulnerable plaques at risk of rupture, can be imaged using (18)F-NaF PET. We aimed to determine whether a motion correction technique applied to gated (18)F-NaF PET images could enhance image quality and improve uptake estimates.
Seventeen patients with myocardial infarction (n = 7) or stable angina (n = 10) underwent (18)F-NaF PET and prospective coronary CT angiography. PET data were reconstructed in 4 different ways: the first was 1 gated bin (end-diastolic phase with 25% of the counts), the second was 4 gated bins (consecutive 25% segments), the third was 10 gated bins (consecutive 10% segments), and the fourth was ungated. Subsequently, with data from either 4 or 10 bins, gated PET images were registered using a local, nonlinear motion correction method guided by the extracted coronary arteries from CT angiography. Global noise levels and target-to-background ratios (TBR) defined on manually delineated coronary plaque lesions were compared to assess image quality and uptake estimates.
Compared with the reference standard of using only 1 bin of PET data, motion correction using 10 bins of PET data reduced image noise by 46% (P < 0.0001). TBR in positive lesions for 10-bin motion-corrected data was 11% higher than for 1-bin data (1.98 [interquartile range, 1.70-2.37] vs. 1.78 [1.58-2.16], P = 0.0027) and 33% higher than for ungated data (1.98 [1.70-2.37] vs. 1.49 [1.39-1.88], P < 0.0001).
Motion correction of gated (18)F-NaF PET/coronary CT angiography is feasible, reduces image noise, and increases TBR. This improvement may allow more reliable identification of vulnerable coronary artery plaques using (18)F-NaF PET.
冠状动脉粥样硬化斑块破裂常导致急性心肌梗死。最近的研究表明，冠状动脉内的活性微钙化（易破裂的不稳定斑块的特征之一）可以使用（18）F-NaF PET 进行成像。我们旨在确定应用于门控（18）F-NaF PET 图像的运动校正技术是否可以提高图像质量并改善摄取估计值。
17 例心肌梗死（n = 7）或稳定型心绞痛患者（n = 10）接受（18）F-NaF PET 和前瞻性冠状动脉 CT 血管造影检查。以 4 种不同方式重建 PET 数据：第一种为 1 个门控 bin（舒张末期，占总计数的 25%），第二种为 4 个门控 bin（连续 25%节段），第三种为 10 个门控 bin（连续 10%节段），第四种为非门控。随后，使用来自 CT 血管造影的提取的冠状动脉，用局部非线性运动校正方法对来自 4 个或 10 个 bin 的门控 PET 图像进行配准。通过比较手动勾画的冠状动脉斑块病变的全局噪声水平和靶与背景比值（TBR），评估图像质量和摄取估计值。
与仅使用 1 个 PET 数据 bin 的参考标准相比，使用 10 个 PET 数据 bin 的运动校正可使图像噪声降低 46%（P < 0.0001）。对于 10 个 bin 运动校正数据，阳性病变的 TBR 比 1 个 bin 数据高 11%（1.98[四分位距，1.70-2.37] vs. 1.78[1.58-2.16]，P = 0.0027），比非门控数据高 33%（1.98[1.70-2.37] vs. 1.49[1.39-1.88]，P < 0.0001）。
门控（18）F-NaF PET/冠状动脉 CT 血管造影的运动校正可行，可降低图像噪声并增加 TBR。这种改善可能使使用（18）F-NaF PET 更可靠地识别易损的冠状动脉斑块。
