Varying diffusion curvature, intravoxel incoherent motion, and conventional monoexponential diffusion models for evaluating Ki-67 expression in rectal carcinoma
- 1Department of Radiology, Henan Provincial People’s Hospital and Zhengzhou University People’s Hospital
- 2Department of MRI, The First Affiliated Hospital of Henan Medical University
- 3Clinical and Technical Support, Philips Healthcare
Abstract
Objectives: This study aimed to systematically evaluate and compare the diagnostic performance of three diffusion models — varying diffusion curvature (VDC), intravoxel incoherent motion (IVIM), and conventional monoexponential diffusion-weighted imaging (DWI) — in predicting Ki-67 expression status in rectal adenocarcinoma.
Methods: A total of 84 patients with rectal carcinoma were enrolled, comprising 48 cases with high proliferative activity (Ki-67 > 50%) and 36 cases with low proliferative activity (Ki-67 ≤ 50%). All patients underwent pelvic MRI examinations. The following imaging parameters were calculated and compared: VDC-derived parameters (D ₀ , D ₁ ), IVIM-derived parameters (ADC slow , ADC fast , f), and the DWI-derived parameter (ADC). Logistic regression analysis was performed to identify independent predictive factors, and diagnostic performance was assessed using the area under the receiver operating characteristic curve (AUC), the DeLong test, and calibration curves.
Results: Compared with the low-proliferation group, the high-proliferation group of rectal carcinoma exhibited significantly higher D ₁ and f values, along with markedly lower D ₀ , ADC, and ADC slow values (all P < 0.05). Logistic regression analysis identified D ₁ and ADC slow as independent predictors of Ki-67 status in rectal carcinoma. The combined diagnostic model incorporating D ₁ and ADC slow yielded an AUC of 0.924, which was significantly superior to the individual parameters, including ADC (AUC = 0.780), ADC slow (AUC = 0.832), D ₀ (AUC = 0.696), D ₁ (AUC = 0.857), and f (AUC = 0.802) (all P < 0.05). The calibration curve demonstrated good stability and reliability of the combined diagnostic model.
Conclusion: Both VDC, IVIM, and DWI demonstrate efficacy in evaluating the Ki-67 expression status in rectal carcinoma. The combined parameters of D ₁ and ADC slow may serve as a novel and reliable imaging biomarker for assessing the proliferative activity of rectal carcinoma.
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BibTeX
@article{cui2026varying,
title = {{Varying diffusion curvature, intravoxel incoherent motion, and conventional monoexponential diffusion models for evaluating Ki-67 expression in rectal carcinoma}},
author = {Yingying Cui and Huijia Yin and Ying Wang and Yue Liu and Yaping Wu and Yan Bai and Hanhan Li and Baiyan Jiang and Nan Meng and Xuan Yu},
journal = {Frontiers in Oncology},
year = {2026},
month = oct,
doi = {10.3389/fonc.2026.1935475},
url = {https://www.frontiersin.org/articles/10.3389/fonc.2026.1935475/full},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Varying diffusion curvature, intravoxel incoherent motion, and conventional monoexponential diffusion models for evaluating Ki-67 expression in rectal carcinoma
AU - Yingying Cui
AU - Huijia Yin
AU - Ying Wang
AU - Yue Liu
AU - Yaping Wu
AU - Yan Bai
AU - Hanhan Li
AU - Baiyan Jiang
AU - Nan Meng
AU - Xuan Yu
PY - 2026
DA - 2026/10/21
JO - Frontiers in Oncology
DO - 10.3389/fonc.2026.1935475
UR - https://www.frontiersin.org/articles/10.3389/fonc.2026.1935475/full
AB - Objectives: This study aimed to systematically evaluate and compare the diagnostic performance of three diffusion models — varying diffusion curvature (VDC), intravoxel incoherent motion (IVIM), and conventional monoexponential diffusion-weighted imaging (DWI) — in predicting Ki-67 expression status in rectal adenocarcinoma. Methods: A total of 84 patients with rectal carcinoma were enrolled, comprising 48 cases with high proliferative activity (Ki-67 > 50%) and 36 cases with low proliferative activity (Ki-67 ≤ 50%). All patients underwent pelvic MRI examinations. The following imaging parameters were calculated and compared: VDC-derived parameters (D ₀ , D ₁ ), IVIM-derived parameters (ADC slow , ADC fast , f), and the DWI-derived parameter (ADC). Logistic regression analysis was performed to identify independent predictive factors, and diagnostic performance was assessed using the area under the receiver operating characteristic curve (AUC), the DeLong test, and calibration curves. Results: Compared with the low-proliferation group, the high-proliferation group of rectal carcinoma exhibited significantly higher D ₁ and f values, along with markedly lower D ₀ , ADC, and ADC slow values (all P < 0.05). Logistic regression analysis identified D ₁ and ADC slow as independent predictors of Ki-67 status in rectal carcinoma. The combined diagnostic model incorporating D ₁ and ADC slow yielded an AUC of 0.924, which was significantly superior to the individual parameters, including ADC (AUC = 0.780), ADC slow (AUC = 0.832), D ₀ (AUC = 0.696), D ₁ (AUC = 0.857), and f (AUC = 0.802) (all P < 0.05). The calibration curve demonstrated good stability and reliability of the combined diagnostic model. Conclusion: Both VDC, IVIM, and DWI demonstrate efficacy in evaluating the Ki-67 expression status in rectal carcinoma. The combined parameters of D ₁ and ADC slow may serve as a novel and reliable imaging biomarker for assessing the proliferative activity of rectal carcinoma.
SN - 2234-943X
ER -