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Optimal high b‐value for diffusion weighted MRI in diagnosing high risk prostate cancers in the peripheral zone
Author(s) -
Agarwal Harsh K.,
Mertan Francesca V.,
Sankineni Sandeep,
Bernardo Marcelino,
Senegas Julien,
Keupp Jochen,
Daar Dagane,
Merino Maria,
Wood Bradford J.,
Pinto Peter A.,
Choyke Peter L.,
Turkbey Baris
Publication year - 2017
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.25353
Subject(s) - medicine , diffusion mri , peripheral , prostate , prostate cancer , radiology , value (mathematics) , multiparametric mri , magnetic resonance imaging , nuclear medicine , cancer , statistics , mathematics
Purpose To retrospectively determine the optimal b‐value(s) of diffusion‐weighted imaging (DWI) associated with intermediate–high risk cancer in the peripheral zone (PZ) of the prostate. Materials and Methods Forty‐two consecutive patients underwent multi b‐value (16 evenly spaced b‐values between 0 and 2000 s/mm 2 ) DWI along with multi‐parametric MRI (MP‐MRI) of the prostate at 3 Tesla followed by trans‐rectal ultrasound/MRI fusion guided targeted biopsy of suspicious lesions detected at MP‐MRI. Computed DWI images up to a simulated b‐value of 4000 s/mm 2 were also obtained using a pair of b‐values (b = 133 and 400 or 667 or 933 s/mm 2 ) from the multi b‐value DWI. The contrast ratio of average intensity of the targeted lesions and the background PZ was determined. Receiver operator characteristic curves and the area under the curve (AUCs) were obtained for separating patients eligible for active surveillance with low risk prostate cancers from intermediate–high risk prostate cancers as per the cancer of the prostate risk assessment (CAPRA) scoring system. Results The AUC first increased then decreased with the increase in b‐values reaching maximum at b = 1600 s/mm 2 (0.74) with no statistically significant different AUC of DWI with b‐values 1067–2000 s/mm 2 . The AUC of computed DWI increased then decreased with the increase in b‐values reaching a maximum of 0.75 around b = 2000 s/mm 2 . There was no statistically significant difference between the AUC of optimal acquired DWI and either of optimal computed DWI. Conclusion The optimal b‐value for acquired DWI in differentiating intermediate–high from low risk prostate cancers in the PZ is b = 1600 s/mm 2 . The computed DWI has similar performance as that of acquired DWI with the optimal performance around b = 2000 s/mm 2 . Level of Evidence: 4 J. Magn. Reson. Imaging 2017;45:125–131.