Currently, Dr. Jiang Du is developing novel quantitative ultrashort echo time magnetization transfer (UTE-MT) imaging and signal modeling techniques to quantify water and macromolecule proton fractions and exchange rates in short T2 tissues such as cortical bone. The UTE-MT modeling parameters are magic angle insensitive, and may be used to evaluate tissue degeneration more reliably than conventional biomarkers such as T2 and T1rho which are very sensitive to the magic angle effect.
Color mapping of MT modeling parameters from an ex vivo bovine cortical bone specimen, including macromolecular fraction (f) (a), proton exchange rate from the macromolecular to water (RMow)
(b), T2 relaxation time of the macromolecular pool (T2m)
(c), and spin-lattice relaxation rate of the water pool (R1w)
UTE-MT imaging of an Achilles tendon sample with a series of angular orientations relative to the B0 field (left), and M modeling parameters such as macromolecular fraction (f), proton exchange rate from the macromolecular to water pools (RMow), T2 relaxation time of the macromolecular pool (T2m), and spin-lattice relaxation rate of the water pool (R1w), which are nearly angular independent. In comparison, conventional T2 is very sensitive to the angular orientation with more than six times longer T2 when the sample is reoriented from parallel to 64° relative to the B0 field.