Diagnostic criterion of diffusion-weighted imaging for prostatic peripheral zone cancer / 中国医学影像技术

ABSTRACT

Objective To evaluate and testify the diagnostic efficacy of the ADC value of the diffusion-weighted imaging (DWI) in prostatic peripheral zone cancer. Methods There were 40 patients with prostatic diseases proved by ultrasound guided systemic biopsy. DWI scans were performed with 1.5T MR scanner using TOSORPA coil and b value of 800 s/mm2. The peripheral zones of prostate were divided in six areas and were attributed to noncancerous and cancerous areas according to the results of biopsy. The minimal ADC values of each peripheral zone were recorded and analyzed. Results There were 240 areas, in which 89 areas were cancerous and the others were noncancerous. The mean ADC value of cancerous areas was (0.98±0.30)×10-3 mm2/s, while the noncancerous areas was (1.59±0.29)×10-3 mm2/s. The diagnostic sensitivity, specificity and accuracy were 80.58%, 92.42% and 86.73% respectively with cutoff point ≤1.24×10-3 mm2/s, whereas 66.56%, 96.95% and 86.26% respectively with cutoff point ≤1.04×10-3 mm2/s. The diagnostic sensitivity was 98.63%, the specificity was 37.07%, the accuracy was 58.82% with cutoff point <1.69×10-3 mm2/s. Conclusion The ADC value ≤1.24×10-3 mm2/s should be regarded as the diagnostic standard of prostate cancer. When ADC value is between (1.04-1.24)×10-3 mm2/s, some cancer might be missed.