TY - JOUR
T1 - A linear algorithm of the reference region model for DCE-MRI is robust and relaxes requirements for temporal resolution
AU - Cárdenas-Rodríguez, Julio
AU - Howison, Christine M.
AU - Pagel, Mark D.
N1 - Funding Information:
The authors would like to thank Dr. Natajan Raghunand, Dr. Arthur Gmitro, Dr. Xiaomeng Zhang, and Mr. Mir Salek for helpful discussions. This work was supported by the University of Arizona Cancer Center and the National Cancer Institute under grants P50 CA95060 and PO1 CA017094. JCR was supported through the US Army Medical Research and Materiel Command under grant number W81XWH-09-1-0053.
PY - 2013/5
Y1 - 2013/5
N2 - Dynamic contrast enhanced MRI (DCE-MRI) has utility for improving clinical diagnoses of solid tumors, and for evaluating the early responses of anti-angiogenic chemotherapies. The Reference Region Model (RRM) can improve the clinical implementation of DCE-MRI by substituting the contrast enhancement of muscle for the Arterial Input Function that is used in traditional DCE-MRI methodologies. The RRM is typically fitted to experimental results with a non-linear least squares algorithm. This report demonstrates that this algorithm produces inaccurate and imprecise results when DCE-MRI results have low SNR or slow temporal resolution. To overcome this limitation, a linear least-squares algorithm has been derived for the Reference Region Model. This new algorithm improves accuracy and precision of fitting the Reference Region Model to DCE-MRI results, especially for voxel-wise analyses. This linear algorithm is insensitive to injection speeds, and has 300- to 8000-fold faster calculation speed relative to the non-linear algorithm. The linear algorithm produces more accurate results for over a wider range of permeabilities and blood volumes of tumor vasculature. This new algorithm, termed the Linear Reference Region Model, has strong potential to improve clinical DCE-MRI evaluations.
AB - Dynamic contrast enhanced MRI (DCE-MRI) has utility for improving clinical diagnoses of solid tumors, and for evaluating the early responses of anti-angiogenic chemotherapies. The Reference Region Model (RRM) can improve the clinical implementation of DCE-MRI by substituting the contrast enhancement of muscle for the Arterial Input Function that is used in traditional DCE-MRI methodologies. The RRM is typically fitted to experimental results with a non-linear least squares algorithm. This report demonstrates that this algorithm produces inaccurate and imprecise results when DCE-MRI results have low SNR or slow temporal resolution. To overcome this limitation, a linear least-squares algorithm has been derived for the Reference Region Model. This new algorithm improves accuracy and precision of fitting the Reference Region Model to DCE-MRI results, especially for voxel-wise analyses. This linear algorithm is insensitive to injection speeds, and has 300- to 8000-fold faster calculation speed relative to the non-linear algorithm. The linear algorithm produces more accurate results for over a wider range of permeabilities and blood volumes of tumor vasculature. This new algorithm, termed the Linear Reference Region Model, has strong potential to improve clinical DCE-MRI evaluations.
KW - Dynamic contrast enhanced MRI
KW - Gd-DTPA
KW - Linear models
KW - Permeability
KW - Pharmacokinetics
KW - Reference region model
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U2 - 10.1016/j.mri.2012.10.008
DO - 10.1016/j.mri.2012.10.008
M3 - Article
C2 - 23228309
AN - SCOPUS:84876121358
VL - 31
SP - 497
EP - 507
JO - Magnetic Resonance Imaging
JF - Magnetic Resonance Imaging
SN - 0730-725X
IS - 4
ER -