[en] The purpose of this study was to establish signal intensity and morphological criteria for evaluating prostatic lesions on endorectal surface coil MR imaging performed before biopsy. Endorectal MR examinations were performed in 81 consecutive patients with elevated level of prostate-specific-antigen and clinically suspected of having prostate cancer before the biopsy. Axial and sagittal fast spin-echo T2-weighted images were obtained in all patients and dynamic images in 36 patients. Prostatic biopsy was performed transperineally after MRI examination with a transrectal ultrasonography to obtain 12 specimens with symmetric fashion. On evaluating T2WI and dynamic images, two radiologists divided the prostate into 12 sections according to the same sites for the biopsy and evaluated the presence of lesions and possibility of malignancy. The signal intensity was defined as very low (lower than muscle), low (similar to muscle) and slightly low (higher than muscle and lower than PZ); the shape of lesions as oval, wedge, tubular and irregular; and the internal characteristic as homogenous, inhomogeneous, reticular and linear. Signal intensity of prostate was also measured in dynamic images to determine the pattern of the enhancement objectively. The results of imaging analysis were directly correlated with the biopsy and surgical specimen findings. The sensitivity, specificity, and accuracy of T2-weighted images for prostatic cancer were 98, 57, and 67% respectively. All lesions with wedge shape and those with linear or reticular characteristic were benign; 41% of lesions with irregular shape and 48% of inhomogeneous lesions were malignant. Signal intensity of lesions on T2WI did not corroborate with the histological findings. On dynamic images, 42% of lesions with early enhancement were malignant and 84% of lesions with delayed enhancement were benign. Low intensity prostatic lesions with wedge and tubular shapes and those with linear or reticular internal architecture on pre-biopsy T2WI could be considered as benign lesions. Dynamic imaging was inferior to the T2WI on the detection of malignancy. (author)