Yanyan Xu1, Hongliang Sun1, Kaining Shi2, and Wu Wang1
1Radiology, China-Japan Friendship hospital, Beijing, China, People's Republic of, 2Philips Healthcare China, Beijing, China, People's Republic of
Synopsis
Dynamic contrast-enhanced
magnetic resonance imaging (DCE-MRI) has been applied in rectal cancer for the
purpose of characterizing tumor perfusion[1]. However, DCE-MRI should use
intravenous contrast media based gadolinium, which will increase the risk of
kidney systemic fibrosis[2]. The bi-exponential analysis in intravoxel incoherent
motion (IVIM) model can separate microscopic circulation perfusion with pure
water diffusion[3-4]. Correlation has been derived between the IVIM perfusion
parameters f and D* and the classical perfusion parameters[5-6]. However, its
relationship with DCE-MRI parameters in rectal cancer has not been clarified.Purpose
To determine the correlation between intravoxel incoherent motion (IVIM)
and multiphase dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI)
parameters in patients with rectal cancer.
Methods
Twenty-one patients with histological diagnosis of rectal
cancer were included in this study. All pelvis magnetic resonance imaging were
performed in a 3.0T MR unit (Philips 3.0T Ingenia, Philips Medical System, The
Netherlands) including diffusion-weighted imaging using eight b values (0, 25,
50, 75, 150, 400, 800 and 1000s/mm2) and DCE-MRI (40 dynamic phases).
IVIM perfusion-related parameters (f, perfusion fraction; D*,
pseudo-diffusion coefficient; f·D*, the multiplication of the two
parameters) were calculated by bi-exponential analysis. Semi-quantitative
DCE-MRI parameters including relative enhancement (RE), maximum enhancement
(ME), maximum relative enhancement (MRE), time to peak (TTP), wash in rate
(WIR) were automatically calculated after region of interest (ROI) being
selected along the outline of tumor maximal dimension, meanwhile relevant
signal intensity (SI) time curves were obtained. Correlations between f and
all semi-quantitative DCE-MRI parameters were respectively analyzed using
Pearson’s correlation coefficients, D* and f·D* were also
similarly analyzed. Interobserver agreements were evaluated using the
intraclass correlation coefficient (ICC) and Bland-Altman analysis. P＜0.05 was considered to
indicate a statistically significant difference.
Results
There were 16 males and 5 females with a median age of 61.7
years (range, 38-76 years). Interobserver reproducibility were good
(ICC=0.8537-0.9754; narrow with of 95% limits of agreement). There were
significant correlation between D*and TTP (r= -0.468; p=0.033),
f·D*and TTP (r= -0.474; p=0.030), no correlation was
observed between f and other DCE-MRI parameters.
Conclusion: IVIM
perfusion-related parameters demonstrated moderate correlations with DCE-MRI
semi-quantitative parameters in rectal cancer.
Conclusion
IVIM
perfusion-related parameters demonstrated moderate correlations with DCE-MRI
semi-quantitative parameters in rectal cancer.
Acknowledgements
This work was supported by a grant from the National Natural Science Foundation of China (No. 81501469).References
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