关键词: 前列腺病变, 经直肠实时组织弹性成像, 磁共振成像, 影像学特点, 诊断

Abstract:

Objective To explore the application and imaging characteristics of transrectal real-time tissue elastography （TRTE） combined with magnetic resonance imaging （MRI） in the diagnosis of benign and malignant prostate lesions. Methods A total of 154 patients with suspected prostate cancer were collected and received TRTE and MRI. The imaging characteristics were analyzed， and the diagnostic value of TRTE and MRI on benign and malignant prostate lesions was evaluated with the pathological result of needle biopsy as the gold standard. Results Among the 154 patients， 79 malignant cases （prostate cancer， 51.30%） and 75 benign cases （benign prostatic hyperplasia， 48.70%） were pathologically diagnosed by needle biopsy. The malignant prostate lesions in the TRTE image were mainly manifested as lesions with a predominantly blue core （high stiffness， low strain）， often with green margins or transitions （moderate strain， moderate stiffness）. In MRI images， the lesions primarily exhibited low signal intensity on T2WI， high signal intensity on DWI， and low signal intensity on ADC， and early and obvious enhancement on DCE. Compared with patients with benign lesions， those with malignant lesions exhibited significantly older age and higher mean biopsy frequency， total prostate specific antigen （tPSA）， prostate-specific antigen density （PSAD）， SR scores and PI-RADS score （P < 0.05）. Compared with clinicopathological diagnosis （gold standard）， the diagnostic efficiency of TRTE and MRI based on binary classification showed no statistically significant difference in distinguishing benign from malignant prostate lesions （P > 0.05）. Multivariate logistic regression analysis revealed that after adjusting for age and PSAD， TRTE elasticity score and MRI PI-RADS score were predictive factors for prostate malignancy （P < 0.05）. Consequently， a prostate malignancy risk model was constructed as logit（P） = -0.421 + 0.072 × age + 0.087 × PSAD + 0.181 × elasticity score + 0.358 × PI-RADS V2.1 score. Taking the pathological diagnosis result as the gold standard， the sensitivities of TRTE， MRI and logistic regression model constructed by TRTE combined with MRI in the diagnosis of benign and malignant prostate lesions were 81.01%， 84.81% and 94.94%， and the specificities were 88.00%， 82.67% and 85.33%. The logistic regression model constructed by TRTE combined with MRI had the best diagnostic efficiency （area under the curve of 0，933）. Conclusions The TRTE signs of lesions with a predominantly blue core and the MRI signs of T2WI low signal， DWI high signal， ADC low signal， DCE “fast in and fast out” enhancement are helpful to the diagnosis of benign and malignant prostate lesions. TRTE combined with MRI is helpful to enhance the diagnostic efficiency.

Key words: prostate lesions, transrectal real-time tissue elastography, magnetic resonance imaging, imaging characteristics, diagnose