Data from: Assessment of tumor treatment response using active contrast encoding (ACE)-MRI: comparison with conventional DCE-MRI

Purpose: To investigate the validity of contrast kinetic parameter
estimates from Active Contrast Encoding (ACE)-MRI against those from
conventional Dynamic Contrast-Enhanced (DCE)-MRI for evaluation of tumor
treatment response in mouse tumor models. Methods: The ACE-MRI method that
incorporates measurement of T1 and B1 into the enhancement curve washout
region, was implemented on a 7T  MRI scanner to measure tracer
kinetic model  parameters of 4T1 and GL261 tumors with treatment
using bevacizumab and 5FU. A portion of the same ACE-MRI data was used for
conventional DCE-MRI data analysis with a separately measured pre-contrast
T1 map. Tracer kinetic model  parameters, such as Ktrans
(permeability area surface product) and ve (extracellular space volume
fraction), estimated from ACE-MRI were compared with those from DCE-MRI,
in terms of  correlation and Bland-Altman analyses. 
Results: A three-fold increase of the median Ktrans by treatment was
observed in the flank 4T1 tumors by both ACE-MRI and DCE-MRI. In contrast,
the brain tumors did not show a significant change by the treatment in
either ACE-MRI or DCE-MRI. Ktrans and ve values  of the tumors
from ACE-MRI were strongly correlated with those from DCE-MRI methods with
correlation coefficients of 0.92 and 0.78, respectively, for the median
values of 17 tumors. The Bland-Altman plot analysis showed a mean
difference of -0.01 /min for Ktrans with the 95% limits of
agreement of -0.12 /min to 0.09 /min, and -0.05 with -0.37 to
0.26 for ve. Conclusion: The  tracer kinetic model parameters
estimated from ACE-MRI and their changes by treatment closely matched
those of DCE-MRI, which suggests that ACE-MRI can be used in place of
conventional DCE-MRI for tumor progression monitoring and treatment
response evaluation with a reduced scan time.