In vivo Visualization of Alzheimer's Amyloid Plaques without a Contrast Agent

Reference #:

2004-139

Inventors/Contributors

Joseph F. Poduslo, Ph.D., Clifford R. Jack Jr., M.D., Thomas M. Wengenack, Ph.D., Geoffry L. Curran, B.S., Bret J. Borowski, RTR

Description

One of the cardinal pathologic features of Alzheimer's disease (AD) is formation of senile or amyloid, plaques. Transgenic mice have been developed that express one or more of the genes responsible for familial AD in humans. Doubly transgenic mice develop "human-like" plaques, providing a mechanism to study amyloid plaque biology in a controlled manner. Imaging of labeled plaques has been accomplished with other modalities, but only MR has sufficient spatial and contrast resolution to enable visualization of individual plaques non-invasively. We describe efforts to optimize visualization of plaques in vivo in transgenic mice at 9.4 T using a long TE spin echo sequence. Preliminary results indicated that a spin echo acquisition more accurately reflects true plaque size, while a T2* weighted gradient echo sequence reflects plaque iron content not plaque size. In vivo MR - ex vivo MR - in vitro histological correlations are provided. We were able to visualize histologically verified plaques as small as 50 um in diameter in the living animal. To our knowledge this work represents the first demonstration of non-invasive in vivo visualization of individual plaques without the use of a contrast agent.

Patent Status

Pending