Zhao Li1, Chaohsiung Hsu1, Ryan Quiroz1, and Yung-Ya Lin1
Early
detection of high-grade malignancy, such as glioblastoma
multiforme (GBM), using enhanced MRI techniques significantly increases
not only the treatment options available, but also the patients’ survival rate.
For this purpose, a conceptually new approach, termed “Active-Feedback MRI”,
was developed. An active feedback electronic device was homebuilt to implement
active-feedback pulse sequences to generate avalanching spin amplification and
fixed-point spin dynamics, which enhances the local magnetic-field gradient variations
due to irregular water contents and deoxyhemoglobin concentration in early GBM.
Statistical results (N=22) for in vivo orthotopic xenografts GBM mouse
models at various cancer stages validate the superior contrast and robustness
of this approach (tumor time constant differs from that of the healthy brain tissue
by +24%) towards early GBM detection than conventional T1-weighted (+2.6%) and
T2-weighted images (-3.1%). This novel approach provides 4-8 times of improvements
in early GBM tumor contrast, as measured by "tumor to normal tissue
contrast", “contrast-to-noise ratio” (CNR) or “Visibility”.
