Diagnostic Value of Double Contrast-Enhanced Ultrasonography for Colorectal Lesions

Objective to investigate the clinical value of double contrast-enhanced ultrasonography (DCUS) in the differential diagnosis of colorectal lesions and preoperative TN staging of colorectal cancer. A total of 479 patients with positive findings on double contrast-enhanced ultrasonography who underwent surgical treatment at the Affiliated Hospital of Guangdong Medical University from November 2019 to December 2024 were enrolled. All patients underwent preoperative DCUS examination. Using pathological results as the gold standard, the diagnostic accuracy of DCUS for colorectal lesions was calculated, and the concordance between preoperative ultrasound-based TN staging and postoperative pathological TN staging was analyzed. Among 479 eligible patients, the ultrasound diagnoses were consistent with pathological diagnoses (carcinoma, inflammation, adenoma, stromal tumor, lymphoma, appendiceal tumor, ovarian tumor, and lipoma) in 96.5% of cases. In 421 patients with colorectal cancer, the accuracy of T staging (T1, T2, T3, T4a, T4b) was 0.96, 0.82, 0.63, 0.79, and 0.97, respectively, with a micro-average accuracy of 0.83. The accuracy of N staging (N0, N1, N2) was 0.62, 0.68, and 0.80, respectively, with a micro-average accuracy of 0.70. Although the overall accuracy of T staging is relatively satisfactory, the diagnostic performance for certain stages such as T3 and N staging remains moderate. This is related to the subjectivity of TN staging and its high dependence on the clinical experience of ultrasound diagnosticians, which tends to result in misdiagnosis. Overall, double contrast-enhanced ultrasonography is an effective imaging modality for the diagnosis of colorectal lesions and provides important reference value for preoperative TN staging in patients with colorectal cancer. This study not only demonstrates the clinical value of double-contrast ultrasonography (DCUS) in evaluating colorectal lesions, but also highlights its unique advantages of being non-invasive, radiation-free, and cost-effective compared with CT and MRI, providing a more convenient and safe first-line imaging option for clinical diagnosis.