Related Experiment Video
Updated: Mar 10, 2026
Tracking the Mammary Architectural Features and Detecting Breast Cancer with Magnetic Resonance Diffusion Tensor Imaging
Published on: December 15, 2014
PI-RADS version 2: quantitative analysis aids reliable interpretation of diffusion-weighted imaging for prostate
Sung Yoon Park1, Su-Jin Shin2,3, Dae Chul Jung1
1Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul, 120-752, Republic of Korea.
Objectives:
To determine whether apparent diffusion coefficient (ADC) ratio aids reliable interpretation of diffusion-weighted imaging (DWI) for prostate cancer (PCa).
Methods:
Seventy-six consecutive patients with PCa who underwent DWI and surgery were included. Based on pathologic tumour location, two readers independently performed DWI scoring according to the revised Prostate Imaging Reporting and Data System (PI-RADSv2). ADC ratios of benign to cancerous prostatic tissue were then measured independently and compared between cases showing concordant and discordant DWI scores ≥4. Area under the curve (AUC) and threshold of ADC ratio were analyzed for DWI scores ≥4.
Results:
The rate of inter-reader disagreement for DWI score ≥4 was 11.8% (9/76). ADC ratios were higher in concordant vs. discordant DWI scores ≥4 (median, 1.7 vs. 1.1-1.2; p < 0.001). For DWI scores ≥4, the AUCs of ADC ratios were 0.970 for reader 1 and 0.959 for reader 2. In patients with an ADC ratio >1.3, the rate of inter-reader disagreement for DWI score ≥4 decreased to 5.9-6.0%. An ADC ratio >1.3 yielded 100% (reader 1, 54/54; reader 2, 51/51) positive predictive value for clinically significant cancer.
Conclusion:
ADC ratios may be useful for reliable interpretation of DWI score ≥4 in PI-RADSv2.
Key Points:
• The ADC ratio correlated positively with DWI score of PI-RADSv2. • ADC ratio >1.3 was associated with concordant interpretation of DWI score ≥4. • ADC ratio >1.3 was associated with high PPV for clinically significant cancer. • ADC ratio is useful for reliable interpretation of DWI scoring in PI-RADSv2.
