Comparative study of ultrasonic elastography and conventional ultrasound in diagnosis of malignant anus neoplasm.

The application value of conventional ultrasound and ultrasonic elastography (UE) in preoperative diagnosis and combined diagnosis of malignant anus neoplasms was investigated. One hundred and twenty patients, whose mass was detected by digital rectal examination, were examined using UE and conventional ultrasound before operation, and the results were compared with those of histopathological examinations after operation, so that the accuracy and imaging features of UE as well as UE combined with conventional ultrasound in diagnosing malignant anus neoplasm were analyzed. Among the 120 patients, 77 were diagnosed with benign lesions and 43 were diagnosed with malignant lesions via pathological diagnosis for anal canal lesion surgery. Conventional ultrasound before operation showed that 53 patients were diagnosed with benign lesions and 26 with malignant lesions. Compared with that in the pathological diagnosis results, the diagnostic accordance rate in preoperative conventional ultrasound was 65.8%. Through UE diagnosis, 66 patients had benign lesions and 39 patients had malignant lesions. Compared with that in the pathological diagnosis results, the diagnostic accordance rate in preoperative UE was 87.5%. After the examination via UE combined with conventional ultrasound before operation, 71 patients were diagnosed with benign lesions and 40 patients were diagnosed with malignant lesions; compared with that in the pathological diagnosis results, the diagnostic accordance rate was 92.5%. In terms of mass qualitative diagnosis, the sensitivity and specificity of conventional ultrasound were 60.5 and 68.8%, respectively; those of UE were 90.7 and 85.7%, respectively, and those of UE combined with conventional ultrasound were 93.0 and 92.2%, respectively. According to the analysis results of receiver operating characteristic (ROC) curve, the area under curve (AUC) of malignant anus neoplasm diagnosed via UE was 0.732 [95% confidence interval (95% CI), 0.211-2.534], the AUC via conventional ultrasound was 0.695 (95% CI, 0.517-0.932), and that via UE combined with conventional ultrasound was 0.823 (95% CI, 0.146-4.643). In conclusion, examinations utilizing UE combined with conventional ultrasound can increase the preoperative diagnostic accordance rate in malignant anus neoplasm, which can be used as an effective method for preoperative diagnosis of malignant anus neoplasm.