Use of biexponential and stretched exponential models of intravoxel incoherent motion and dynamic contrast-enhanced magnetic resonance imaging to assess the proliferation of endometrial carcinoma

Abstract

Background: It is important to assess the proliferation of endometrial carcinoma (EC) noninvasively using imaging methods. This prospective diagnostic study investigated the value of biexponential and stretched exponential models of intravoxel incoherent motion (IVIM) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in predicting the Ki-67 status of EC.Methods: In all, 70 patients with EC underwent pelvic MRI. The diffusion coefficient (D), pseudo diffusion coefficient (D*), perfusion fraction (f), distributed diffusion coefficient (DDC), water molecular diffusion heterogeneity index (α), volume transfer constant (K trans ), rate transfer constant (K ep ), and volume of extravascular extracellular space per unit volume of tissue (V e ) were compared. The area under the receiver operating characteristic (ROC) curve (AUC) was used to quantify diagnostic efficacy. Multivariate logistic regression and bootstrap (1,000 samples) analyses were used to establish and evaluate, respectively, the optimal model to predict Ki-67 status.Results: D, K trans , and K ep were lower while α was higher in the high-proliferation group as compared with low-proliferation group (all P values<0.05). D and K ep were independent predictors of Ki-67 status in EC, and the combination of these parameters had optimal diagnostic efficacy (AUC 0.920; sensitivity 85.71%; specificity 89.29%), which was significantly better than that of D (AUC 0.753; Z=2.874; P=0.004), α (AUC 0.715; Z=3.505; P=0.001), K trans (AUC 0.808; Z=2.741; P=0.006), and K ep (AUC 0.832; Z=2.147; P=0.032) alone. The validation model showed good accuracy (AUC 0.882; 95% confidence interval 0.861-0.897) and consistency (C-statistic =0.902). D, K ep , K trans , and α showed a slightly negative (r=-0.271), moderately negative (r=-0.534), slightly negative (r=-0.409), and slightly positive (r=0.488) correlation with the Ki-67 index, respectively (all P values <0.05).Conclusions: IVIM-and DCE-MRI-derived parameters, including D, α, K trans , and K ep , were associated with Ki-67 status in EC, and the combination of D and K ep may serve as a superior imaging marker for the identification of low-and high-proliferation EC.

A comparative study of mono-exponential and advanced diffusion-weighted imaging in differentiating stage IA endometrial carcinoma from benign endometrial lesions

“…A lower α value indicates a higher intravoxel diffusion heterogeneity caused by multi-exponential signal attenuation. Several previous studies have demonstrated that diffusion index α correlates with histological heterogeneity (Zhang et al 2023 ; Liu et al 2015 ). However, in our study, α did not show a significant difference between malignant and benign groups, presumably as our study focused on IAEC.…”

Multi-b-value DWI to evaluate the synergistic antiproliferation and anti-heterogeneity effects of bufalin plus sorafenib in an orthotopic HCC model

“…where S(0) represents the signal intensity without diffusion-weighting, S(b) represents the signal intensity at a particular b. D t (in 10 -3 mm 2 /s) represents the true diffusion coefficient reflecting the diffusion of water molecules inside and outside the cell; D p (in 10 -3 mm 2 /s) is the pseudo-diffusion coefficient, while f represents the perfusion fraction [22].…”

“…Future robust studies with different b-value settings and postprocessing models might worth further exploring. D p and f reflected microcirculatory perfusion [22], and were found positively correlated with angiogenic factors [27]. However, due to the interference of tissue structure, tortuous vascularity, particle or gland excretion, and different components, such as capillaries that cannot reflect the macroscopic tumors and vessels [28], it is challenging for D p and f to reliably depict tumor cell proliferation in studies of endometrial carcinoma and lung adenocarcinoma [22,29].…”

“…D p and f reflected microcirculatory perfusion [22], and were found positively correlated with angiogenic factors [27]. However, due to the interference of tissue structure, tortuous vascularity, particle or gland excretion, and different components, such as capillaries that cannot reflect the macroscopic tumors and vessels [28], it is challenging for D p and f to reliably depict tumor cell proliferation in studies of endometrial carcinoma and lung adenocarcinoma [22,29]. Our study in HCCs showed good and positive correlation between f and MVD, which demonstrated the value of f for accurate reflection of tumor microcirculation.…”