PURPOSE: To evaluate and compare the reproducibility of the preferred phenomenological parameter IAUC60 (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 T1 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 IAUC60 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 IAUC60 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. 2006 Wiley-Liss, Inc.
PURPOSE: To evaluate and compare the reproducibility of the preferred phenomenological parameter IAUC60 (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 T1 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 IAUC60 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 IAUC60 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. 2006 Wiley-Liss, Inc.
Authors: Robert E Lee; E Brian Welch; Jared G Cobb; Tuhin Sinha; John C Gore; Thomas E Yankeelov Journal: J Digit Imaging Date: 2008-04-30 Impact factor: 4.056
Authors: Moira C Ferrier; Hemant Sarin; Steve H Fung; Bawarjan Schatlo; Ryszard M Pluta; Sandeep N Gupta; Peter L Choyke; Edward H Oldfield; David Thomasson; John A Butman Journal: Neoplasia Date: 2007-07 Impact factor: 5.715
Authors: S J Mills; C Soh; J P B O'Connor; C J Rose; G Buonaccorsi; S Cheung; S Zhao; G J M Parker; A Jackson Journal: AJNR Am J Neuroradiol Date: 2009-12-17 Impact factor: 3.825