Comparative study into the robustness of compartmental modeling and model-free analysis in DCE-MRI studies

✍ Scribed by Caleb Roberts; Basma Issa; Andrew Stone; Alan Jackson; John C. Waterton; Geoffrey J.M. Parker

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 317 KB
• Volume: 23
• Category: Article
• ISSN: 1053-1807
• DOI: 10.1002/jmri.20529

✦ Synopsis

Abstract

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.