Xu Zeyan, Zhao Ke, Han Lujun, Li Pinxiong, Shi Zhenwei, Huang Xiaomei, Han Chu, Wang Huihui, Chen Minglei, Liu Chen, Liang Yanting, Li Suyun, Huang Yanqi, Chen Xin, Liang Changhong, Cao Wuteng, Liu Zaiyi
School of Medicine, South China University of Technology, Guangzhou 510006, China.
State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou 510060, China.
Precis Clin Med. 2021 Apr 30;4(2):119-128. doi: 10.1093/pcmedi/pbab011. eCollection 2021 Jun.
Distinguishing anorectal malignant melanoma from low rectal cancer remains challenging because of the overlap of clinical symptoms and imaging findings. We aim to investigate whether combining quantitative and qualitative magnetic resonance imaging (MRI) features could differentiate anorectal malignant melanoma from low rectal cancer.
Thirty-seven anorectal malignant melanoma and 98 low rectal cancer patients who underwent pre-operative rectal MRI from three hospitals were retrospectively enrolled. All patients were divided into the primary cohort (N = 84) and validation cohort (N = 51). Quantitative image analysis was performed on T1-weighted (T1WI), T2-weighted (T2WI), and contrast-enhanced T1-weighted imaging (CE-T1WI). The subjective qualitative MRI findings were evaluated by two radiologists in consensus. Multivariable analysis was performed using stepwise logistic regression. The discrimination performance was assessed by the area under the receiver operating characteristic curve (AUC) with a 95% confidence interval (CI).
The skewness derived from T2WI (T2WI-skewness) showed the best discrimination performance among the entire quantitative image features for differentiating anorectal malignant melanoma from low rectal cancer (primary cohort: AUC = 0.852, 95% CI 0.788-0.916; validation cohort: 0.730, 0.645-0.815). Multivariable analysis indicated that T2WI-skewness and the signal intensity of T1WI were independent factors, and incorporating both factors achieved good discrimination performance in two cohorts (primary cohort: AUC = 0.913, 95% CI 0.868-0.958; validation cohort: 0.902, 0.844-0.960).
Incorporating T2WI-skewness and the signal intensity of T1WI achieved good performance for differentiating anorectal malignant melanoma from low rectal cancer. The quantitative image analysis helps improve diagnostic accuracy.
由于临床症状和影像学表现存在重叠，鉴别肛管直肠恶性黑色素瘤与低位直肠癌仍然具有挑战性。我们旨在研究结合定量和定性磁共振成像（MRI）特征是否能够区分肛管直肠恶性黑色素瘤与低位直肠癌。
回顾性纳入了来自三家医院的37例肛管直肠恶性黑色素瘤患者和98例接受术前直肠MRI检查的低位直肠癌患者。所有患者被分为初级队列（N = 84）和验证队列（N = 51）。对T1加权（T1WI）、T2加权（T2WI）和对比增强T1加权成像（CE-T1WI）进行定量图像分析。由两名放射科医生共同评估主观定性MRI表现。使用逐步逻辑回归进行多变量分析。通过受试者操作特征曲线（AUC）下的面积及95%置信区间（CI）评估鉴别性能。
在区分肛管直肠恶性黑色素瘤与低位直肠癌的所有定量图像特征中，T2WI的偏度（T2WI-偏度）显示出最佳的鉴别性能（初级队列：AUC = 0.852，95% CI 0.788 - 0.916；验证队列：0.730，0.645 - 0.815）。多变量分析表明，T2WI-偏度和T1WI的信号强度是独立因素，将这两个因素结合在两个队列中均取得了良好的鉴别性能（初级队列：AUC = 0.913，95% CI 0.868 - 0.958；验证队列：0.902，0.844 - 0.960）。
结合T2WI-偏度和T1WI的信号强度在区分肛管直肠恶性黑色素瘤与低位直肠癌方面表现良好。定量图像分析有助于提高诊断准确性。
