Abstract: To investigate the clinical value of transrectal ultrasound combined with prostate specific antigen density (PSAD) in the diagnosis of prostate cancer, 97 patients with elevated PSA from September 2013 to September 2018 were enrolled in the study. All patients were examined by transrectal ultrasound and PSAD, compared with the pathological results. The PSAD inspection results were observed, and the diagnosis coincidence rate of transrectal ultrasound+PSAD and the pathological examination was analyzed. Then the accuracy, sensitivity and specificity of the the transrectal ultrasonography combined with PSAD were compared with those of pathological examination. Finally, the imaging features and internal echo of transrectal ultrasonography in patients with prostate cancer were analyzed. The detection rate of prostate cancer, transitional cell carcinoma and mucinous adenocarcinoma by transrectal ultrasound and PSAD was slightly lower than pathological examination (P>0.05). The accuracy, sensitivity and specificity of transrectal ultrasound combined with PSAD were slightly lower than those of pathological examination (P>0.05). According to the ultrasound image, the cancer can be divided into three types:diffuse, nodular and no nodular. The imaging characteristics and internal echo of different types are different. It is indicated that the accuracy of transrectal ultrasound combined with PSAD in the diagnosis of prostate cancer is high, which can clearly reflect the internal echo of different disease types. It is worth popularizing because of its high clinical practical value.

Key words: transrectal ultrasound, PSAD, prostate cancer, detection rate of lesions, imaging characteristics, internal echo