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 T 1 ‐weighted MRI has limited clinical translation. We evaluated whether Dynamic Contrast Enhanced‐Magnetic Resonance Fingerprinting (DCE‐MRF), which directly generates quantitative T 1 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) T 1 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 ( RK trans and k ep,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 RK trans across all regions and timepoint comparisons, and 1.3‐to‐1.9‐fold larger effect sizes for tumor rim k ep,T compared to conventional DCE‐MRI. RK trans and k ep,T at 3 h post‐treatment in all regions, detected significant vascular recovery for whole tumor RK trans and both whole tuomor and tumor rim for k ep,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.