  Quantitative MRI enables direct quantification of contrast agent
concentrations in contrast-enhanced scans. However, the lengthy scan times
required by conventional methods are inadequate for tracking contrast agent
transport dynamically in mouse brain. We developed a 3D MR fingerprinting (MRF)
method for simultaneous T1 and T2 mapping across the whole mouse brain with
4.3-min temporal resolution. We designed a 3D MRF sequence with variable
acquisition segment lengths and magnetization preparations on a 9.4T
preclinical MRI scanner. Model-based reconstruction approaches were employed to
improve the accuracy and speed of MRF acquisition. The method's accuracy for T1
and T2 measurements was validated in vitro, while its repeatability of T1 and
T2 measurements was evaluated in vivo (n=3). The utility of the 3D MRF sequence
for dynamic tracking of intracisternally infused Gd-DTPA in the whole mouse
brain was demonstrated (n=5). Phantom studies confirmed accurate T1 and T2
measurements by 3D MRF with an undersampling factor up to 48. Dynamic
contrast-enhanced (DCE) MRF scans achieved a spatial resolution of 192 x 192 x
500 um3 and a temporal resolution of 4.3 min, allowing for the analysis and
comparison of dynamic changes in concentration and transport kinetics of
intracisternally infused Gd-DTPA across brain regions. The sequence also
enabled highly repeatable, high-resolution T1 and T2 mapping of the whole mouse
brain (192 x 192 x 250 um3) in 30 min. We present the first dynamic and
multi-parametric approach for quantitatively tracking contrast agent transport
in the mouse brain using 3D MRF.
