TY - JOUR
T1 - Linearization improves the repeatability of quantitative dynamic contrast-enhanced MRI
AU - Jones, Kyle M.
AU - Pagel, Mark D.
AU - Cárdenas-Rodríguez, Julio
N1 - Funding Information:
This study was supported by the National Cancer Institute of the National Institutes of Health under award numbers R01CA167183 , R01CA197029 , and P30CA023074 . K.M.J. is supported by a fellowship from NIH grants T32HL007955 and T32HL066988.
Publisher Copyright:
© 2017 Elsevier Inc.
PY - 2018/4
Y1 - 2018/4
N2 - Purpose The purpose of this study was to compare the repeatabilities of the linear and nonlinear Tofts and reference region models (RRM) for dynamic contrast-enhanced MRI (DCE-MRI). Materials and methods Simulated and experimental DCE-MRI data from 12 rats with a flank tumor of C6 glioma acquired over three consecutive days were analyzed using four quantitative and semi-quantitative DCE-MRI metrics. The quantitative methods used were: 1) linear Tofts model (LTM), 2) non-linear Tofts model (NTM), 3) linear RRM (LRRM), and 4) non-linear RRM (NRRM). The following semi-quantitative metrics were used: 1) maximum enhancement ratio (MER), 2) time to peak (TTP), 3) initial area under the curve (iauc64), and 4) slope. LTM and NTM were used to estimate Ktrans, while LRRM and NRRM were used to estimate Ktrans relative to muscle (RKtrans). Repeatability was assessed by calculating the within-subject coefficient of variation (wSCV) and the percent intra-subject variation (iSV) determined with the Gage R&R analysis. Results The iSV for RKtrans using LRRM was two-fold lower compared to NRRM at all simulated and experimental conditions. A similar trend was observed for the Tofts model, where LTM was at least 50% more repeatable than the NTM under all experimental and simulated conditions. The semi-quantitative metrics iauc64 and MER were as equally repeatable as Ktrans and RKtrans estimated by LTM and LRRM respectively. The iSV for iauc64 and MER were significantly lower than the iSV for slope and TTP. Conclusion In simulations and experimental results, linearization improves the repeatability of quantitative DCE-MRI by at least 30%, making it as repeatable as semi-quantitative metrics.
AB - Purpose The purpose of this study was to compare the repeatabilities of the linear and nonlinear Tofts and reference region models (RRM) for dynamic contrast-enhanced MRI (DCE-MRI). Materials and methods Simulated and experimental DCE-MRI data from 12 rats with a flank tumor of C6 glioma acquired over three consecutive days were analyzed using four quantitative and semi-quantitative DCE-MRI metrics. The quantitative methods used were: 1) linear Tofts model (LTM), 2) non-linear Tofts model (NTM), 3) linear RRM (LRRM), and 4) non-linear RRM (NRRM). The following semi-quantitative metrics were used: 1) maximum enhancement ratio (MER), 2) time to peak (TTP), 3) initial area under the curve (iauc64), and 4) slope. LTM and NTM were used to estimate Ktrans, while LRRM and NRRM were used to estimate Ktrans relative to muscle (RKtrans). Repeatability was assessed by calculating the within-subject coefficient of variation (wSCV) and the percent intra-subject variation (iSV) determined with the Gage R&R analysis. Results The iSV for RKtrans using LRRM was two-fold lower compared to NRRM at all simulated and experimental conditions. A similar trend was observed for the Tofts model, where LTM was at least 50% more repeatable than the NTM under all experimental and simulated conditions. The semi-quantitative metrics iauc64 and MER were as equally repeatable as Ktrans and RKtrans estimated by LTM and LRRM respectively. The iSV for iauc64 and MER were significantly lower than the iSV for slope and TTP. Conclusion In simulations and experimental results, linearization improves the repeatability of quantitative DCE-MRI by at least 30%, making it as repeatable as semi-quantitative metrics.
KW - Dynamic contrast-enhanced MRI
KW - Linear models
KW - Pharmacokinetics
KW - Reference region model
KW - Repeatability
KW - Tofts model
UR - http://www.scopus.com/inward/record.url?scp=85034454773&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85034454773&partnerID=8YFLogxK
U2 - 10.1016/j.mri.2017.11.002
DO - 10.1016/j.mri.2017.11.002
M3 - Article
C2 - 29155024
AN - SCOPUS:85034454773
SN - 0730-725X
VL - 47
SP - 16
EP - 24
JO - Magnetic Resonance Imaging
JF - Magnetic Resonance Imaging
ER -