Value of Quantitative DCE-MRI restaging the Status of Regional Lymph Nodes With a Short-Axis Diameter ≥ 5 mm for Rectal Cancer

Motivation: Structural MRI has been demonstrated to be inaccurate in the assessment of regional lymph nodes (LNs) with a short diameters ≥ 5 mm following neoadjuvant therapy for rectal cancer. Goal(s): To explore the potential of quantitative DCE-MRI in predicting the status of LNs ≥ 5 mm on MRI restaging. Approach: Quantitative DCE-MRI parameters of LNs including the forward volume transfer constant (Ktrans), rate constant (kep), and fractional extravascular extracellular space volume (Ve) were measured, and compared with histopathological findings. Results: Ktrans and kep demonstrated moderate diagnostic performance, and had high sensitivity in distinguishing malignant nodes from benign nodes. Impact: Quantitative DCE-MRI can improve the accuracy of nodal restaging in rectal cancer after neoadjuvant therapy, and subsequently conducive to therapeutic evaluation and formulation of next treatment strategies.