Quantitative Time-Dependent Diffusion MRI for Diagnosis and Aggressiveness Assessment of Endometrial Cancer: A Prospective Study.

Abstract

Objective: Preoperative differentiation of benign and malignant endometrial lesions, along with the identification of aggressive histological types of endometrial cancer (EC), is crucial for guiding treatment strategies. Time-dependent diffusion magnetic resonance imaging (TDD-MRI), which allows the characterization of tissue microstructure at the cellular level, is not currently applied for endometrial lesions. This study aimed to evaluate TDD-MRI-derived microstructural parameters for noninvasively distinguishing benign and malignant endometrial lesions and predicting aggressive histological types of EC.

Materials and methods: This prospective study enrolled 177 patients with clinically suspected EC who underwent TDD-MRI between January 2024 and March 2025. The Imaging Microstructural Parameters Using Limited Spectrally Edited Diffusion method was used to extract microstructural parameters, including the cell diameter (d), intracellular volume fraction (v_in), cellularity (number of cells per unit area), cellularity index (v_in/d), and extracellular diffusivity (D_ex), along with three apparent diffusion coefficient measurements. The area under the receiver operating characteristic curve (AUC) was used to assess diagnostic performance. The Pearson correlation coefficient between the microstructural parameters and histopathological measurements was calculated.

Results: A total of 130 women (mean ± standard deviation age: 56 ± 14 years) administered uterine curettage or surgery were included in the final analysis. All microstructural parameters showed significant differences between benign endometrial lesions and EC (P < 0.05), as well as between nonaggressive and aggressive EC (P < 0.05). Cellularity exhibited the highest AUC of 0.86 for distinguishing benign endometrial lesions from EC, whereas the cellularity index showed the highest AUC of 0.88 for distinguishing aggressive histological types. D_0Hz was positively correlated with D_ex (P < 0.05) and negatively correlated with diameter (P < 0.05), cellularity index (P < 0.01) and v_in (P < 0.001) in patients with benign endometrial lesions. D_0Hz was positively correlated with D_ex (P < 0.001) and negatively correlated with v_in (P < 0.001) in patients with EC. Microstructural parameters strongly correlated with corresponding pathological features (r = 0.77-0.83; P < 0.001).

Conclusion: TDD-MRI-derived microstructural parameters demonstrated high performance in differentiating benign from malignant endometrial diseases and identifying aggressive types of EC.