Avalanching Amplification of MRI Lesion Contrast by Nonlinear Feedback
Huang S, Mathern G, Chute D, Akhtari M, Lin Y, Vinters H, Datta S, Walls J
University of California, Los Angeles
Extracting image contrast from small variations in MRI parameters is vital in distinguishing physiological changes leading to a pathologic state. We present a new approach to enhance MRI contrast based on nonlinear feedback fields induced by the spins themselves. Changes in the distribution of an initially unstable magnetization configuration act back on the spins through the feedback fields to amplify contrast. We demonstrate avalanching amplification of MRI contrast due to small differences in resonance frequency under the distant dipolar field and radiation damping feedback interactions and observe up to 20 times improved contrast in epileptogenic lesions and malignant brain tumors.