Diagnostic value of different gradient diffusion-weighted imaging for prostate cancer / 中国基层医药

ABSTRACT

Objective:To investigate the value of diffusion-weighted imaging (DWI) quantitative parameters with different b values in the diagnosis of prostate cancer and its correlation with prostate cancer diagnosis to determine the optimal b values.Methods:Forty-one patients with pathologically confirmed prostate cancer who were admitted by Yuyao People's Hospital from May 2019 to April 2021 were included in this study. Forty-seven foci were selected to undergo 1.5T MR high-resolution T 2-weighted imaging (T 2WI) and DWI. Four different b values (800, 1 000, 1 500, 2 000 s/mm 2) were applied to DWI. The apparent diffusion coefficient (ADC) values and areas of tumor region were measured on different b-value ADC maps. Tumor signal intensity and area were measured on DWI. The same area in the same layer was selected as the reference area to calculate and analyze the signal intensity. Results:The ADC values of tumor area were 0.93 ± 0.21, 0.87 ± 0.19, 0.76 ± 0.17 and 0.68 ± 0.14 when b values were 800, 1 000, 1 500 and 2 000 s/mm 2, respectively, which were significantly different from the ADC values of the reference area (1.59 ± 0.26, 1.50 ± 0.27, 1.28 ± 0.25, and 1.08 ± 1.84, t = 13.53, 13.08, 11.79, 7.30, all P < 0.01). However, there was no significant difference in the signal intensity ratio (-0.26, -0.27, -0.25, -0.22) on the ADC maps of tumor area under different b values ( P = 0.52). The DWI signal intensities of tumor region were 68.2 ± 19.1, 59.5 ± 18.8, 47.9 ± 17.7, and 50.1 ± 11.5, respectively when b values were 800, 1 000, 1 500, and 2 000 s/mm 2, respectively, which were significantly different from the DWI signal intensities of reference area (49.1 ± 17.7, 38.7 ± 11.3, 25.3 ± 6.9, 19.6 ± 4.5, t = 5.02, 6.50, 9.43, 16.93, all P < 0.01). DWI signal intensity ratio of tumor region at the b value of 800 s/mm 2 was significantly different from that at the b value of 1 000, 1 500 and 2 000 s/mm 2 (0.16 vs. 0.21, 0.30, 0.33, t = 10.84, 23.27, 22.85, all P < 0.01). DWI signal intensity ratio at the b value of 1 000 s/mm 2 was significantly different from that at the b value of 1 500 and 2 000 s/mm 2 ( t = 12.34, 14.10, both P < 0.01). Conclusion:High b-value DWI ( b ≥ 1 500 s/mm 2) has a remarkable advantage in the diagnosis of prostate cancer over low b-value DWI.