Nonamnestic Alzheimer disease (AD) variants, including posterior cortical atrophy and the logopenic variant of primary progressive aphasia, differ from amnestic AD in distributions of tau aggregates and neurodegeneration. We evaluated whether ¹⁸F-flortaucipir (also called ¹⁸F-AV-1451) PET, targeting tau aggregates, detects these differences, and we compared the results with MRI measures of gray matter (GM) atrophy. Methods: Five subjects with posterior cortical atrophy, 4 subjects with the logopenic variant of primary progressive aphasia, 6 age-matched patients with AD, and 6 control subjects underwent ¹⁸F-flortaucipir PET and MRI. SUV ratios and GM volumes were compared using regional and voxel-based methods. Results: The subgroups showed the expected ¹⁸F-flortaucipir–binding patterns. Group effect sizes were generally stronger with ¹⁸F-flortaucipir PET than with MRI volumes. There were moderate-to-high correlations between regional GM atrophy and ¹⁸F-flortaucipir uptake. ¹⁸F-flortaucipir binding and GM atrophy correlated similarly to cognitive test performance. Conclusion: ¹⁸F-flortaucipir binding corresponds to the expected neurodegeneration patterns in nonamnestic AD, with potential for earlier detection of pathology than is possible with MRI atrophy measures.

非遗忘性阿尔茨海默病（AD）变体，包括后皮质萎缩和原发性进行性失语症的轻体变体，在tau聚集体分布和神经变性方面不同于失忆性AD。我们评估了靶向tau聚集体的¹⁸ F-flortaucipir（也称为¹⁸ F-AV-1451）PET是否检测到这些差异，并将结果与​​MRI灰质（GM）萎缩的测量结果进行了比较。方法：对5名患有后皮质萎缩的受试者，4名具有原发性进行性失语症的低位变异的受试者，6名年龄相匹配的AD患者和6名对照受试者进行了¹⁸ F氟尿嘧啶PET和MRI检查。使用区域方法和基于体素的方法比较了SUV比率和GM量。结果：亚组显示出预期的^18种F-flortaucipir结合模式。通常，使用¹⁸ F-氟尿嘧啶PET的组效应大小要强于MRI体积。区域性GM萎缩和¹⁸ F-花胶的摄取之间存在中度至高相关性。¹⁸ F-flortaucipir结合和GM萎缩与认知测试表现相似。结论： ¹⁸ F-弗洛托菲尔结合对应于非遗忘性AD中预期的神经退行性变，具有比MRI萎缩措施更早发现病理的潜力。