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Updated: Jul 2, 2026
Advanced Animal Model of Colorectal Metastasis in Liver: Imaging Techniques and Properties of Metastatic Clones
Published on: November 30, 2016
Colorectal liver metastases: contrast agent diffusion coefficient for quantification of contrast enhancement
Guang Jia1, Craig O'Dell, Johannes T Heverhagen
1Department of Radiology and the Wright Center of Innovation in Biomedical Imaging, the Ohio State University, Columbus, OH 43210, USA.
Purpose:
To describe and determine the reproducibility of a simplified model to quantitatively measure heterogeneous intralesion contrast agent diffusion in colorectal liver metastases.
Materials And Methods:
This HIPAA-compliant retrospective study received institutional review board approval, and written informed consent was obtained from 14 patients (mean age, 61 years +/- 9 [standard deviation]; range, 41-78 years), including 10 men (mean age, 65 years +/- 8; range, 47-78 years) and four women (mean age, 54 years +/- 9; range, 41-59 years), with colorectal liver metastases. Magnetic resonance (MR) imaging was performed twice (first baseline MR image [B(1)] and second baseline MR image [B(2)]) in a single target lesion prior to therapy. Dynamic contrast material-enhanced MR imaging was performed by using a saturation-recovery fast gradient-echo sequence. A simplified contrast agent diffusion model was proposed, and a contrast agent diffusion coefficient (CDC) was calculated. The reproducibility of the CDC measurement was evaluated by using the Bland-Altman plot and a linear regression model.
Results:
The mean CDC was 0.22 mm(2)/sec (range, 0.01-0.73 mm(2)/sec) on B(1) and 0.24 mm(2)/sec (range, 0.01-0.71 mm(2)/sec) on B(2), with an intraclass correlation coefficient of 0.91 (P < .0001). Bland-Altman plot showed good agreement, with a mean difference in measurement pairs of 0.017 mm(2)/sec +/- 0.096. The slope from the linear regression model was 0.89 (95% confidence interval: 0.63, 1.15) and the intercept was 0.01 (95% confidence interval: -0.08, 0.09).
Conclusion:
The CDC enables a quantitative description of contrast enhancement heterogeneity in lesions. Given the high reproducibility of the CDC metric, CDC appears promising for further qualification as an imaging biomarker of change measurement in response assessment.
Supplemental Material:
http://radiology.rsnajnls.org/cgi/content/full/248/3/901/DC1.
Insights
A simplified model accurately measures contrast agent diffusion in colorectal liver metastases. The contrast diffusion coefficient (CDC) demonstrated high reproducibility, showing promise as an imaging biomarker for treatment response assessment.
Area of Science:
- Radiology
- Medical Imaging
- Oncology
Background:
- Accurate measurement of intralesion contrast agent diffusion is crucial for assessing treatment response in colorectal liver metastases.
- Existing models may not fully capture the heterogeneity of contrast diffusion within these lesions.
Purpose of the Study:
- To describe and evaluate the reproducibility of a simplified model for quantifying heterogeneous intralesion contrast agent diffusion.
- To determine the reliability of the contrast diffusion coefficient (CDC) as a measurement metric.
Main Methods:
- Retrospective analysis of dynamic contrast-enhanced MRI data from 14 patients with colorectal liver metastases.
- Application of a simplified contrast agent diffusion model to calculate the contrast diffusion coefficient (CDC).
- Assessment of CDC reproducibility using Bland-Altman plots and linear regression analysis.
Main Results:
- The mean CDC showed minimal variation between two baseline MRI scans (B(1) and B(2)).
- High reproducibility was confirmed by an intraclass correlation coefficient of 0.91 (P < .0001).
- Bland-Altman analysis indicated good agreement with a mean difference of 0.017 mm(2)/sec.
Conclusions:
- The simplified model and CDC metric provide a quantitative measure of contrast enhancement heterogeneity.
- The high reproducibility of the CDC suggests its potential as a reliable imaging biomarker for monitoring treatment response.
