Patterns of 11C-PIB cerebral retention in mild cognitive impairment patients
I Banzo1, J F Jiménez-Bonilla1, I Martínez-Rodríguez1
1Department of Nuclear Medicine, Molecular Imaging Group (IDIVAL), Marqués de Valdecilla University Hospital, University of Cantabria, Santander, Spain.
Objective:
To evaluate the patterns of cerebral cortical distribution of (11)C-PIB in patients with mild cognitive impairment (MCI).
Material And Methods:
The study included 69 patients (37 male, age range 42-79 years) with MCI, sub-classified as 53 with amnestic-MCI (A-MCI), and 16 with non-amnestic-MCI (NA-MCI). Patients underwent (11)C-PIB PET/CT scan 60min after intravenous injection of the radiotracer. A visual analysis of the images was performed by 2 experienced physicians. (11)C-PIB-positive studies were considered when gray matter uptake was equal to or greater than white matter. According to the regions involved, (11)C-PIB-positive studies were classified into A-pattern (predominant retention in frontal, anterior cingulate, lateral temporal, and basal ganglia) and B-pattern (generalized retention).
Results:
Thirty-nine of the 69 (56%) patients with MCI showed (11)C-PIB retention. Of the 53 A-MCI patients, 36 (68%) showed (11)C-PIB retention. Eleven out of 36 (30%) positive scans in A-MCI patients showed A-pattern, and 25 out of 36 (70%) patients had a B-pattern. Positive (11)C-PIB was observed in 3 out of 16 (19%) patients with NA-MCI. Regional distribution in these 3 patients showed A-pattern in 1, and B-pattern in 2 patients.
Conclusion:
Cortical retention of (11)C-PIB was more frequent in A-MCI than in NA-MCI patients, and also B-pattern than A-pattern in the (11)C-PIB positive group. The recognition of (11)C-PIB distribution patterns allows MCI patients to be classified, and the A-pattern may offer a therapeutic window for potential future treatments.
Insights
Cerebral cortical distribution of carbon-11 Pittsburgh Compound B (11C-PIB) was evaluated in mild cognitive impairment (MCI) patients. (11)C-PIB retention was more common in amnestic-MCI than non-amnestic-MCI, with a generalized B-pattern more frequent than the A-pattern.
Area of Science:
- Neuroimaging
- Nuclear Medicine
- Cognitive Neurology
Background:
- Mild cognitive impairment (MCI) is a transitional stage between normal aging and dementia.
- Amyloid-beta plaque deposition in the brain is a hallmark of Alzheimer's disease and can be detected using positron emission tomography (PET) tracers.
- (11)C-Pittsburgh Compound B (11C-PIB) is a radiotracer used for PET imaging of amyloid plaques.
Purpose of the Study:
- To investigate the patterns of cerebral cortical distribution of (11)C-PIB in patients diagnosed with MCI.
- To compare (11)C-PIB retention patterns between amnestic MCI (A-MCI) and non-amnestic MCI (NA-MCI) subtypes.
- To identify potential differences in amyloid deposition patterns that may inform future therapeutic strategies.
Main Methods:
- 69 patients with MCI (53 A-MCI, 16 NA-MCI) underwent (11)C-PIB PET/CT scans.
- Visual analysis of PET images was performed by two experienced physicians to assess (11)C-PIB retention.
- (11)C-PIB positive studies were defined by gray matter uptake exceeding white matter uptake.
- Retention patterns were classified as A-pattern (predominant frontal, cingulate, temporal, basal ganglia) or B-pattern (generalized).
Main Results:
- 56% (39/69) of MCI patients showed (11)C-PIB retention.
- Amnestic MCI (A-MCI) patients exhibited higher retention rates (68%, 36/53) compared to NA-MCI patients (19%, 3/16).
- In positive A-MCI scans, the B-pattern (generalized retention) was more prevalent (70%) than the A-pattern (30%).
- In the three positive NA-MCI cases, one showed A-pattern and two showed B-pattern.
Conclusions:
- Cortical (11)C-PIB retention is more frequent in A-MCI than NA-MCI.
- The generalized B-pattern of (11)C-PIB retention is more common than the A-pattern in MCI patients with positive scans.
- Identifying specific (11)C-PIB distribution patterns can aid in classifying MCI patients.
- The A-pattern may represent a potential therapeutic window for future interventions targeting amyloid deposition.
