Abstract
BACKGROUND: The expression level of Ki-67 and the degree of differentiation in pancreatic cancer determine tumor aggressiveness and patient prognosis, which holds significant implications for clinical decision-making. A major challenge in preoperative pancreatic ductal adenocarcinoma management is predicting tumor malignancy. Contrast-enhanced ultrasound (CEUS), a dynamic imaging technique based on blood pool visualization, can reveal lesion vasculature and provide quantitative perfusion data reflecting angiogenesis. By tracking contrast agent kinetics, CEUS offers non-invasive insights into tumor vascularization, helping assess malignancy potential. AIM: To investigate the correlation between Ki-67 and pancreatic cancer differentiation using CEUS quantitative parameters and evaluated their diagnostic accuracy. METHODS: This retrospective study analyzed pancreatic cancer patients who underwent CEUS and pathological confirmation. Pathological differentiation, clinical data, and quantitative CEUS parameters [maximum intensity (IMAX), rise time (RT), rise slope 50% (Rs50), rise slope 10%-90% (Rs1090), etc.] were collected. Based on Ki-67 expression (< 50% vs ≥ 50%), patients were divided into low- and high-expression groups. The study evaluated correlations between Ki-67 expression, differentiation degree, and CEUS quantitative parameters to assess tumor aggressiveness. RESULTS: Among 54 patients (25 high Ki-67, 29 low Ki-67), significant differences (P < 0.05) were observed in Rs50, IMAX, wash-out area under the curve (WoutAUC), wash-in and out area under curve, and Rs1090 between high and low Ki-67 groups. High-expression patients showed elevated Rs50, IMAX, WoutAUC, and area under the curve (AUC), while RT and falling slope 50% (Fs50) were lower. Rs1090 demonstrated the highest diagnostic accuracy (AUC = 0.863, sensitivity = 0.92, specificity = 0.759). Fs50 was effective in low Ki-67 detection (AUC = 0.838). No correlation was found between enhancement patterns and Ki-67 or differentiation. CONCLUSION: CEUS parameters (Rs50, IMAX, WoutAUC, Rs1090) strongly correlate with Ki-67, aiding non-invasive pancreatic cancer assessment. Rs1090/IMAX predict high Ki-67; Fs50 identifies low Ki-67, supporting CEUS for tumor aggressiveness evaluation.