Dynamic Contrast Enhanced-Magnetic Resonance Fingerprinting (DCE-MRF) Improves Detection of Induced Vascular Perfusion Reduction in a Mouse Breast Cancer Model.

PURPOSE: Dynamic contrast-enhanced MRI (DCE-MRI) can assess tumor perfusion using pharmacokinetic models. However, poor DCE-MRI reproducibility from reliance on conventional T1-weighted MRI has limited clinical translation. We evaluated whether Dynamic Contrast Enhanced-Magnetic Resonance Fingerprinting (DCE-MRF), which directly generates quantitative T1 relaxation time constant maps, provides improved precision and statistical power for detecting treatment-induced vascular changes compared to conventional DCE-MRI.

METHODS

Twenty female mice bearing orthotopic 4 T1 breast tumors were randomly assigned to DCE-MRF (n = 12) or conventional DCE-MRI (n = 8) cohorts. Both methods acquired matched spatial and temporal resolution (23-s) T1 measurements at baseline, 3 h, and 48 h post-treatment with combretastatin A4 phosphate (120 mg/kg), a known vascular disrupting agent. Perfusion assessments were obtained with a pharmacokinetic Linear Reference Region Model (RKtrans and kep,T) and model-independent initial area under the curve assessments and compared using Wilcoxon signed-rank tests and Hedges' g effect sizes.

RESULTS

DCE-MRF demonstrated 1.3-to-5.1-fold larger effect sizes for RKtrans across all regions and timepoint comparisons, and 1.3-to-1.9-fold larger effect sizes for tumor rim kep,T compared to conventional DCE-MRI. RKtrans and kep,T at 3 h post-treatment in all regions, detected significant vascular recovery for whole tumor RKtrans and both whole tuomor and tumor rim for kep,T at 48 h, whereas DCE-MRI only detected significant changes at 3 h.

CONCLUSIONS

DCE-MRF's improved measurement precision and increased effect size translates directly to enhanced statistical power for detecting treatment-induced vascular changes, positioning it as a more reproducible tumor perfusion assessment for animal models and eventually cancer patients.