Comparison between PET template-based method and MRI-based method for cortical quantification of florbetapir (AV-45)...

Area of Science:

• Neuroimaging
• Alzheimer's Disease Research
• Biomarker Quantification

Background:

• Florbetapir (AV-45) PET is used to assess amyloid plaque burden in Alzheimer's disease (AD).
• Nonspecific white matter binding can affect the reliability of AV-45 PET analyses.
• Cortical quantification methods may improve the accuracy of AV-45 binding assessment.

Purpose of the Study:

• To compare the reliability of two AV-45 quantification methods: PET template registration (route 1) and MRI-based cortical quantification (route 2).
• To evaluate the effectiveness of each method in discriminating between early-stage Alzheimer's disease patients and healthy controls.

Main Methods:

• Recruited 22 prodromal AD patients and 17 healthy controls.
• Assessed AV-45 binding using both PET template registration and MRI-based cortical quantification.
• Compared quantification results between groups and within groups using discriminant analysis.

Main Results:

• Both methods differentiated between AD patients and controls.
• MRI-based quantification (route 2) showed larger effect sizes for intergroup differences.
• Route 2 demonstrated higher specificity (94.1%) but lower sensitivity (77.3%) compared to route 1 (70.6% specificity, 86.4% sensitivity).
• Discriminant analysis yielded higher D-prime values for route 2.

Conclusions:

• Both quantification methods can distinguish early AD patients from controls.
• PET template-based quantification is adequate for clinical use.
• MRI-based cortical quantification offers greater intergroup discrimination and is potentially more suitable for clinical research.