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1584. Quantitative T2-Mapping Compared to Conventional Echo-Planar and PROPELLER DWI for Multi-Parametric Prostate MRI in Men with Hip Replacement
Authors * Denotes Presenting Author
  1. Paul Sathiadoss *; The Ottawa Hospital/University of Ottawa
  2. Nicola Schieda; The Ottawa Hospital/University of Ottawa
  3. Mohammad Haroon; The Ottawa Hospital/University of Ottawa
  4. Heba Osman; The Ottawa Hospital/University of Ottawa
  5. Matthew McInnes; The Ottawa Hospital/University of Ottawa
  6. Gerd Melkus; The Ottawa Hospital/University of Ottawa
Objective:
To evaluate and compare quantitative T2-mapping, PROPELLER-DWI and conventional echo-planar (EPI)-DWI in men with hip replacement undergoing prostate MRI.

Materials and Methods:
This single-center prospective study evaluated 12 men with hip replacement (9 unilateral and 3 bilateral replacements) undergoing prostate MRI from November 2019-February 2020. T2-maps, PROPELLER-DWI and EPI-DWI were performed in addition to T2-weighted (T2W) and dynamic contrast enhanced (DCE) images. PROPELLER-DWI was reconstructed in MATLAB to generate calculated b1500 mm2/sec DWI and ADC map images. Two blinded radiologists independently evaluated each MRI using PI-RADS sector maps and applied PI-RADS scores to observed lesions with and without PROPELLER-DWI and T2-maps. T2-maps were assessed subjectively using a color-scale and quantitatively using a threshold of <100 msec. Degree of confidence in scoring (1-5) was recorded. T2W, DWI, DCE and T2-maps were evaluated for image quality and susceptibility artifact using 5-point Likert scales at the prostate base, middle and apex levels. Comparisons were performed using Wilcoxon sign-rank tests.

Results:
Mean age was 71±5 years and PSA was 7.3±4.4 ng/mL. 66.6% (8/12) men underwent TRUS-guided prostate biopsy after MRI with 3 clinically significant cancers (ISUP grade group 4 N=2, ISUP grade group 2, N=1), 2 ISUP grade group 1 cancers and 3 negative biopsies. All three clinically significant tumors were detected by both radiologists with T2 times <100 msec which was significantly lower than normal PZ (p<0.001). The degree of confidence scores for both radiologists were significantly higher when using PROPELLER-DWI (p=0.01) and T2-maps (p=0.01) compared to when using EPI-DWI alone. Image quality was significantly higher and artifact significantly lower for (in descending order): T2-maps, PROPELLER DWI and EPI-DWI (p<0.001) for both radiologists.

Conclusion:
Conventional echo-planar DWI is limited in men undergoing prostate MRI with hip replacement, with improved image quality using PROPELLER-DWI and optimal image quality using quantitative T2-maps. PROPELLER-DWI and T2-maps improved degree of confidence during radiologist interpretation and PI-RADS scoring. T2-maps and PROPELLER-DWI can be added to prostate multi-parametric MRI in men with hip replacement to improve functional evaluation of the prostate gland, improve image quality and confidence in interpretation.