Molecular imaging with Pittsburgh compound B confirmed at autopsy - A case report

Objective: To determine the correspondence between uptake of Pittsburgh Compound B (PiB) in life and measures of beta-amyloid (A beta) in postmortem tissue analysis. Patient: A 76-year-old man with a clinical diagnosis of dementia with Lewy bodies underwent fluorodeoxyglucose F-18 and PiB positron emission tomographic brain scans. Imaging revealed marked region specific binding of PiB and abnormal fluorodeoxyglucose uptake. Intervention: Autopsy was performed 3 months after the PiB scan. Results: Autopsy confirmed the clinical diagnosis; in addition, there was severe cerebral amyloid angiopathy and only moderate numbers of parenchymal A beta plaques. Biochemical measures revealed a positive correlation between A beta levels and regional PiB binding. Conclusion: This report confirms that PiB detects A beta in the living patient and demonstrates that amyloid deposited as cerebral amyloid angiopathy can be the dominant source of signal.