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P2‐198: Longitudinal in vivo micro‐anatomic follow‐up of amyloid plaque load by MRI
Author(s) -
Santin Mathieu,
Petiet Alexandra,
Bertrand Anne,
Petit Fanny,
Dorieux Olène,
Kraska Audrey,
JosephMathurin Nelly,
Hantraye Philippe,
Rooney Thomas,
Debeir Thomas,
Dhenain Marc
Publication year - 2011
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2011.05.1083
Subject(s) - in vivo , magnetic resonance imaging , immunohistochemistry , medicine , saline , pathology , genetically modified mouse , toxicity , amyloid (mycology) , gadolinium , nuclear medicine , chemistry , transgene , endocrinology , radiology , biology , biochemistry , microbiology and biotechnology , organic chemistry , gene
polycarbonate. The average signal intensity of tissue surrounding the lateral ventricles was measured in 3T T1-weighted MRI images from ten subjects with AD in the ADNI database. The mixture found to replicate this tissue was made of 2% (w/v) agar dissolved in water, containing 0.01% (w/v) NaCl and a gadopentetate dimeglumine concentration of 0.0375 mM. A brain-shaped mold was filled with tissue-mimicking solution and the ventricle positioned in the middle of the brain. The completed phantom was scanned using the ADNI-specific MP-RAGE sequence. Images were analyzed using a fully-automated segmentation tool. Results: The signal intensity difference between the ventricle and agar solution successfully matched in-vivo signal intensity differences. At a resolution of 1.0 x1.0 x1.0 mm, a volume of 46.6 cm was reported, which is only 2.3% smaller than the actual volume. This result illustrates that the software used does a reasonable job of estimating ventricle volume. The use of the ventricle phantom allowed us to also pinpoint ventricular sub-regions where the algorithm failed. Conclusions: A life-sized MRI-compatible brain ventricle phantom was successfully created. Images acquired are available from the authors to groups wishing to use this data for validation. As enlargement of the ventricles is further established as a marker of disease progression and incorporated into clinical trials, careful validation using gold standards must be performed to ensure the integrity of the study.