双源计算机断层扫描双能量结肠镜检测结肠肿瘤准确性的临床研究

Clinical study on the accuracy of dual-energy computed tomography colonography in colorectal neoplasia detection

目的比较常规CT结肠镜（CTC）与双能量CTC检测占位性病变的准确性。方法选择临床怀疑有结肠占位性病变患者28例，均采用双能量增强CT扫描，并进行结肠镜重建和双能量碘图重建。比较结肠占位性病变的直径、增强后CT值和含碘值。以结肠镜及病理结果作为金标准，比较常规CTC和双能量CTC诊断结肠占位性病变的敏感度、特异度、准确率、阳性预测值和阴性预测值。多组间的计量资料比较采用方差分析，计数资料比较采用卡方检验。结果28例患者中，CTC检出结肠占位性病变24例，经结肠镜及病理证实假阳性4例，假阴性1例。双能量CTC检出结肠占位性病变20例，经结肠镜及病理证实无假阳性患者，假阴性1例。腺瘤样息肉、腺瘤、腺癌和粪块增强后的CT值分别为（38．54±6．82）、（49．16±7．31）、（52．61土5．93）和（34．00±1．41）Hu，腺瘤和腺癌的强化值明显高于腺瘤样息肉和粪块，差异有统计学意义（F=10．760，P=0．001）；息肉与粪块两组间比较，差异无统计学意义（t=1．44，P=0．188）。常规CTC与双能量CTC检测占位性病变的敏感度分别为95．6％（95％CI：77．9％～99．2％）和95．6％（95％CI：77．9％～99．2％），特异度分别为42．8％（95％CI：15．4％～93．5％）和100．0％（95％CI：47．9％～100．0％）。结论与传统的CTC相比，双能量CTC可区分粪便残渣与肿块，有助于肿瘤良恶性的鉴别，进一步提高CTC诊断的准确性。

Objective To compare the accuracy between regular computed tomography colonography （CTC） and dual-energy CTC in lesion detection. Methods Twenty-eight patients with clinical suspicious space occupying lesions of the colon were selected. All patients were underwent dual- energy mode contrast-enhanced CT scan and the data were reconstructed with colonography and dual-energy iodine maps methods. The diameter, enhanced computed tomography （CT） value and iodine value were measured. The results of colonoscopy and pathology were taken as gold standard. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of regular CTC and dual- energy CTC were compared. Variance analysis was performed for measurement data comparison among groups and chi-square test was used for count data analysis. Results Among 28 patients, colorectal lesions were detected in 24 cases by regular CTC, of which four cases were false-positive and one case was false-negative confirmed by colonoscopy and pathology. Colorectal lesions were detected in Z0 cases by dual-energy CTC, of which no false-positive and one case was false negative confirmed by colonoscopy and pathology. The contrast enhanced CT value of polyps, adenoma, adenocarcinoma and stool was （38.54± 6.82）, （49.16±7.31）, （52.61±5.93） and （34. 004±1.41） Hu, respectively. The enhanced value of adenoma and adenocarcinoma was significantly higher than that of polyps and stool, the differences were statistically significant among groups （F= 10. 760, P = 0. 001）. There was no significant difference between polyps and stool （t=1.44, P= 0. 188）. The sensitivity of regular CTC and dual-energy CTC in lesion detection was 95.6% （95%cofidence interval（CI） ： 77.9%-99.2%） and 95.6% （95%CI： 77.9% -99.2%）, respectively. The specificity was 42.8% （95%CI： 15. 4%-93. 5%） and 100.0% （95%CI： 47.9 %-100.0 %）. Conclusion Compared with traditional CTC, dual-energy CTC would distinguish lesions from stool, help differentiate between benign and malignant tumors and further increase the accuracy of CTC diagnosis.