Department of Nuclear Medicine, University of Brescia, Brescia, Italy -
Laboratory of Alzheimer's Neuroimaging and Epidemiology (LANE), San Giovanni di Dio Clinical Research Center, Brescia, Italy.
Q J Nucl Med Mol Imaging. 2020 Dec;64(4):414-421. doi: 10.23736/S1824-4785.19.03124-8. Epub 2019 May 8.
Three different amyloid tracers labeled with 18-flourine have been introduced into clinical use. The leaflets of tracers indicate different visual criteria for PET reporting. In clinical practice, it is not yet ascertained whether these criteria are equivalent in terms of diagnostic accuracy or if anyone is better than another. We aimed to evaluate the inter and intra-rater variability of visual assessment of F-Florbetapir PET/CT images among six independent readers with different clinical experience.
We analyzed 252 PET/CT scans, visually assessed by each reader three times, applying independently the three different reading criteria proposed. Each reader evaluated the regional uptake specifying for each cortical region a numeric value of grading of positivity in order to assign a final score. At the end of each reading a level of confidence was determined by assigning a score from 0 (negative) to 4 (positive). After first reading, those cases in which the evaluations by two experienced readers did not match (discordant cases) were independently reevaluated merging all the three different visual interpretation criteria.
Good agreement was observed for visual interpretation among the six readers' confidence-level using independently the three visual reading criteria: ICC=0.83 (0.80-0.86) for F-florbetapir, ICC=0.84 (0.81-0.87) for F-florbetaben, and ICC=0.86 (0.83-0.88) for F-flutemetamol reading. A good inter-rater agreement was observed for final-score too: ICC=0.74 (0.70-0.78) for F-florbetapir; ICC=0.82 (0.79-0.85) for F-florbetaben; ICC=0.84 (0.81-0.87) for F-flutemetamol. Intra-rater agreement was good for final-score (from 0.76 to 0.90; P<0.001) and confidence-level (Spearman's rho from 0.89 to 1.00; P<0.001). Disagreement between the two experienced readers was observed in 22 of 252 cases (9%). The agreement converged over a second round of independent reading in 12 of 22 cases (54%), by merging all the criteria.
All the criteria proposed are useful to determine the grading of positivity or negativity of amyloid deposition and their merging improves the diagnostic confidence and provides a better agreement.
三种不同的 18 氟标记淀粉样蛋白示踪剂已被引入临床应用。示踪剂的说明书指出了 PET 报告的不同视觉标准。在临床实践中，尚未确定这些标准在诊断准确性方面是否等效，或者是否有一个标准优于另一个标准。我们旨在评估 6 名具有不同临床经验的独立读者对 F-Florbetapir PET/CT 图像进行视觉评估的组内和组间可重复性。
我们分析了 252 例 PET/CT 扫描，由每位读者独立进行了三次评估，分别应用了三种不同的阅读标准。每位读者评估了区域性摄取情况，并为每个皮质区域指定了阳性分级的数值，以便给出最终评分。在每次阅读结束时，通过从 0（阴性）到 4（阳性）给分来确定置信水平。在第一次阅读后，对于两名有经验的读者评估结果不一致的病例（不一致病例），我们通过合并所有三种不同的视觉解释标准来独立重新评估。
使用三种视觉阅读标准，六位读者的置信水平的视觉解释具有良好的一致性：F-florbetapir 的 ICC=0.83（0.80-0.86）、F-florbetaben 的 ICC=0.84（0.81-0.87）和 F-flutemetamol 的 ICC=0.86（0.83-0.88）。最终评分也具有良好的组间一致性：F-florbetapir 的 ICC=0.74（0.70-0.78）、F-florbetaben 的 ICC=0.82（0.79-0.85）和 F-flutemetamol 的 ICC=0.84（0.81-0.87）。最终评分的组内一致性良好（0.76-0.90；P<0.001），置信水平的组内一致性也良好（Spearman's rho 从 0.89 到 1.00；P<0.001）。在 252 例病例中，有 22 例（9%）出现了两位有经验读者之间的不一致。通过合并所有标准，在 22 例病例中的 12 例（54%）中，第二轮独立阅读的一致性得到了改善。
所有提出的标准都有助于确定淀粉样蛋白沉积的阳性或阴性分级，并且合并使用这些标准可以提高诊断信心并提供更好的一致性。
