Brain Disorders & Therapy

Label and radiation-free CEST MRI detection of amyloid: Repurposing of the PiB PET Probe

Global congress on Neuroscience Psychiatry and Mental disorder

July 03, 2023 | Webinar

Caiyu Zhuang

Shantou University Medical College, China

Scientific Tracks Abstracts: Brain Disord Ther

Abstract:

Statement of the Problem: The compound PiB has been radio-labeled for PET imaging of amyloid, which is critical in the detection of amyloid and enables early diagnosis of dementia. This study aims to repurpose PiB for label and radiation-free CEST MRI imaging, which would be promising in clinical transformation. Methodology & Theoretical Orientation: PiB solutions at different concentrations were prepared for the Z-spectra measurements. After optimizing parameters by preliminary experiments, APP/PS1 transgenic mice(n=6) and age-matched C57 mice(n=6) were used for in vivo CEST MRI imaging of amyloid on a 7.0 T MRI scanner. The brains were scanned dynamically after intraperitoneal injection of PiB. Finally, the pathological assessment was conducted in the same brain slices to evaluate the correlation between the MRI signal abnormality and the deposition of beta-amyloid detected by immunohistochemical staining. Findings: The Z spectra revealed a clear CEST effect peaked at approximately 6 ppm, which could be distinguished from the inherent amide proton transfer and magnetization transfer when applied to in vivo CEST MRI imaging. APP/PS1 mice injected with PiB showed a significantly higher in vivo CEST effect when compared with controls and before injections �?p<0.05�?. The distribution of Aβ deposits detected by CEST imaging was consistent with the immunohistochemical staining results. Conclusion & Significance: The present study is the first to repurpose a PET probe to noninvasively evaluate Aβ deposits in APP/PS1 mice. Repurposing of the PiB PET Probe for CEST MRI imaging enables label and radiation-free detection of amyloid and has potential in clinical transformation, especially in the early detection of dementia.

Biography :

Caiyu Zhuang is a PhD candidate for neuroimaging. She is interested in chemical exchange saturation transfer (CEST) MRI, a molecular imaging technique sensitive in detecting in vivo metabolites or probes. She has explored the feasibility of using this technique to detect amyloid deposition in Alzheimer’s disease and also evaluated the efficacy of nanomedicine in treating glioma.