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Comparative study into the robustness of compartmental modeling and model‐free analysis in DCE‐MRI studies
Author(s) -
Roberts Caleb,
Issa Basma,
Stone Andrew,
Jackson Alan,
Waterton John C.,
Parker Geoffrey J.M.
Publication year - 2006
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.20529
Subject(s) - reproducibility , robustness (evolution) , computer science , confidence interval , nuclear medicine , magnetic resonance imaging , medicine , biomedical engineering , radiology , statistics , mathematics , chemistry , biochemistry , gene
Purpose To evaluate and compare the reproducibility of the preferred phenomenological parameter IAUC 60 (initial area under the time‐concentration curve [IAUC] defined over the first 60 seconds postenhancement) with the preferred modeling parameter ( K trans ), as derived using two simple models, in abdominal and cerebral data collected in typical Phase I clinical trial conditions. Materials and Methods Dynamic contrast enhanced MRI (DCE‐MRI) time series were acquired at two imaging centers from a group of patients with abdominal tumors and a group with gliomas. At both imaging centers, precontrast T 1 was calculated using a variable flip angle three‐dimensional spoiled gradient echo acquisition that was used to quantify tissue contrast agent concentration, allowing voxelwise definition of summary DCE‐MRI parameters. Results A comparison of reproducibility showed that there was no statistically significant difference in reproducibility between IAUC 60 and K trans , although there was a trend towards better reproducibility for K trans ( P = 0.0782). The 95% confidence intervals (CIs) for individual changes showed that for IAUC 60 and K trans , changes in excess of 47% and 31%, respectively, are outside the range of normal variability. Conclusion Although modeling is more complex and more computationally intensive than an IAUC parameterization, our data suggest this approach to be preferable to a model‐free approach since it provides greater physiological insight without a reduction in statistical power for Phase I/II clinical drug trials. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.