University of Heidelberg
Faculty of Medicine Mannheim
University Hospital Mannheim
These pages are still under constructions and will be available soon! Please check again later!

If you have questions concerning a specific publication please use this form with subject 'information about publications' and giving the full citation in the message body.

Home > Publications > Abstract >

Using an artificial neural network for fast mapping of the oxygen extraction fraction with combined QSM and quantitative BOLD.

S. Hubertus, S. Thomas, J. Cho, S. Zhang, Y. Wang and L. Schad

Magn Reson Med, 82 (6), pp.2199-2211

To apply an artificial neural network (ANN) for fast and robust quantification of the oxygen extraction fraction (OEF) from a combined QSM and quantitative BOLD analysis of gradient echo data and to compare the ANN to a traditional quasi-Newton (QN) method for numerical optimization. Random combinations of OEF, deoxygenated blood volume ( ), R , and nonblood magnetic susceptibility ( ) with each parameter following a Gaussian distribution that represented physiological gray matter and white matter values were used to simulate quantitative BOLD signals and QSM values. An ANN was trained with the simulated data with added Gaussian noise. The ANN was applied to multigradient echo brain data of 7 healthy subjects, and the reconstructed parameters and maps were compared to QN results using Student t test and Bland-Altman analysis. Intersubject means and SDs of gray matter were OEF %, Hz, %, ppb for ANN; and OEF = %, Hz, %, ppb for QN, with a significant difference ( ) for , , and . For white matter, they were OEF = %, Hz, %, ppb for ANN; and OEF %, Hz, %, ppb for QN, with a significant difference ( ) for OEF and . ANN revealed more gray-white matter contrast but less intersubject variation in OEF than QN. In contrast to QN, the ANN reconstruction did not need an additional sequence for parameter initialization and took approximately 1 s rather than roughly 1 h. ANNs allow faster and, with regard to initialization, more robust reconstruction of OEF maps with lower intersubject variation than QN approaches.

Contact: Dr. Frank Zöllner last modified: 18.11.2019
to top of page