Objective To investigate whether the addition of contrast-enhanced sequences improves the diagnostic value of MRI in Tis-T1 rectal cancer and to compare its diagnostic performance with that of endorectal ultrasound (ERUS). Materials and methods Patients with pathologically confirmed Tis-T2 rectal cancer who underwent curative resection between January 2020 and December 2023 were enrolled. All patients underwent preoperative MRI (including contrast-enhanced sequencing) and ERUS. Tumor shape and the status of muscularis propria (SMP) were evaluated on T2-weighted images by a radiologist, whereas submucosal enhancing stripe (SES) was assessed on contrast-enhanced MRI. An MRI-based combined model was constructed by integrating tumor shape, SMP, and SES features. ERUS-based tumor staging was performed by an endoscopist. The diagnostic performance of SMP, SES, the combined model, and ERUS in identifying stage Tis-T1 lesions was evaluated. The area under the receiver operating characteristic curves (AUCs) was calculated, and statistical differences were assessed using the DeLong method. Results In total, 136 patients (mean age: 60 ± 10 years; 78 men) with 138 lesions (82 Tis-T1 and 56 T2 lesions) were enrolled. The AUC values for SMP, SES, the combined model, and ERUS were 0.762 (95% confidence interval [CI]: 0.682–0.830), 0.861 (95% CI: 0.792–0.914), 0.915 (95% CI: 0.856–0.956), and 0.806 (95% CI: 0.730–0.868), respectively. Adding contrast-enhanced MRI feature significantly improved the diagnostic performance over the common approach (combined model vs SMP: AUC difference = 0.154; p < 0.001), and the combined model was also better than ERUS (AUC difference = 0.109; p = 0.003). Conclusion Incorporating contrast-enhanced MRI improves stage Tis-T1 rectal cancer diagnostic accuracy and outperforms ERUS. Key Points <Emphasis Type="BoldItalic">Question</Emphasis> Can adding contrast-enhanced MRI feature improve the diagnostic performance of MRI in identifying stage Tis-T1 rectal cancer compared to ERUS? <Emphasis Type="BoldItalic">Findings</Emphasis> The MRI-based combined model incorporating contrast-enhanced and T2WI features achieved the best diagnostic performance (AUC value: 0.915), significantly superior to that of ERUS (p = 0.003). <Emphasis Type="BoldItalic">Clinical relevance</Emphasis> Incorporating contrast-enhanced MRI offers a more reliable basis for personalized organ-sparing treatment planning and provides a foundation for future clinical practice guidelines. Graphical Abstract

Contrast-enhanced MRI improves diagnostic accuracy in stage Tis-T1 rectal cancer: a head-to-head comparison with endorectal ultrasound

期刊论文
发表日期：

2026年4月28日

查看全文

Lijuan Wan,
Diliang Li,
Yaqing Kong,
Guoxu Zhao,
Fan Yang,
Mengwen Liu,
Zhe Gao,
Wenwen Fan,
Yuan Liu,
Hongmei Zhang

摘要

Objective

To investigate whether the addition of contrast-enhanced sequences improves the diagnostic value of MRI in Tis-T1 rectal cancer and to compare its diagnostic performance with that of endorectal ultrasound (ERUS).

Materials and methods

Patients with pathologically confirmed Tis-T2 rectal cancer who underwent curative resection between January 2020 and December 2023 were enrolled. All patients underwent preoperative MRI (including contrast-enhanced sequencing) and ERUS. Tumor shape and the status of muscularis propria (SMP) were evaluated on T2-weighted images by a radiologist, whereas submucosal enhancing stripe (SES) was assessed on contrast-enhanced MRI. An MRI-based combined model was constructed by integrating tumor shape, SMP, and SES features. ERUS-based tumor staging was performed by an endoscopist. The diagnostic performance of SMP, SES, the combined model, and ERUS in identifying stage Tis-T1 lesions was evaluated. The area under the receiver operating characteristic curves (AUCs) was calculated, and statistical differences were assessed using the DeLong method.

Results

In total, 136 patients (mean age: 60 ± 10 years; 78 men) with 138 lesions (82 Tis-T1 and 56 T2 lesions) were enrolled. The AUC values for SMP, SES, the combined model, and ERUS were 0.762 (95% confidence interval [CI]: 0.682–0.830), 0.861 (95% CI: 0.792–0.914), 0.915 (95% CI: 0.856–0.956), and 0.806 (95% CI: 0.730–0.868), respectively. Adding contrast-enhanced MRI feature significantly improved the diagnostic performance over the common approach (combined model vs SMP: AUC difference = 0.154; p < 0.001), and the combined model was also better than ERUS (AUC difference = 0.109; p = 0.003).

Conclusion

Incorporating contrast-enhanced MRI improves stage Tis-T1 rectal cancer diagnostic accuracy and outperforms ERUS.

Key Points

Question Can adding contrast-enhanced MRI feature improve the diagnostic performance of MRI in identifying stage Tis-T1 rectal cancer compared to ERUS?

Findings The MRI-based combined model incorporating contrast-enhanced and T2WI features achieved the best diagnostic performance (AUC value: 0.915), significantly superior to that of ERUS (p = 0.003).

Clinical relevance Incorporating contrast-enhanced MRI offers a more reliable basis for personalized organ-sparing treatment planning and provides a foundation for future clinical practice guidelines.

Graphical Abstract