title: Restriction spectrum imaging improves MRI-based prostate cancer detection.
abstract: To compare the diagnostic performance of restriction spectrum imaging (RSI), with that of conventional multi-parametric (MP) magnetic resonance imaging (MRI) for prostate cancer (PCa) detection in a blinded reader-based format.
  
  
  
  Three readers independently evaluated 100 patients (67 with proven PCa) who underwent MP-MRI and RSI within 6 months of systematic biopsy (N = 67; 23 with targeting performed) or prostatectomy (N = 33). Imaging was performed at 3 Tesla using a phased-array coil. Readers used a five-point scale estimating the likelihood of PCa present in each prostate sextant. Evaluation was performed in two separate sessions, first using conventional MP-MRI alone then immediately with MP-MRI and RSI in the same session. Four weeks later, another scoring session used RSI and T2-weighted imaging (T2WI) without conventional diffusion-weighted or dynamic contrast-enhanced imaging. Reader interpretations were then compared to prostatectomy data or biopsy results. Receiver operating characteristic curves were performed, with area under the curve (AUC) used to compare across groups.
  
  
  
  MP-MRI with RSI achieved higher AUCs compared to MP-MRI alone for identifying high-grade (Gleason score greater than or equal to 4 + 3=7) PCa (0.78 vs. 0.70 at the sextant level; P < 0.001 and 0.85 vs. 0.79 at the hemigland level; P = 0.04). RSI and T2WI alone achieved AUCs similar to MP-MRI for high-grade PCa (0.71 vs. 0.70 at the sextant level). With hemigland analysis, high-grade disease results were similar when comparing RSI + T2WI with MP-MRI, although with greater AUCs compared to the sextant analysis (0.80 vs. 0.79).
  
  
  
  Including RSI with MP-MRI improves PCa detection compared to MP-MRI alone, and RSI with T2WI achieves similar PCa detection as MP-MRI.
authors.affiliation: Department of Radiology, University of California San Diego School of Medicine, 200 W Arbor Dr, San Diego, CA, 92103, USA.
authors.forename: Kevin C
authors.initials: KC
authors.lastname: McCammack
authors.affiliation: Department of Radiology, University of California San Diego School of Medicine, 200 W Arbor Dr, San Diego, CA, 92103, USA.
authors.forename: Natalie M
authors.initials: NM
authors.lastname: Schenker-Ahmed
authors.affiliation: Department of Radiology, University of California San Diego School of Medicine, 200 W Arbor Dr, San Diego, CA, 92103, USA.
authors.forename: Nathan S
authors.initials: NS
authors.lastname: White
authors.affiliation: Department of Radiology, University of California San Diego School of Medicine, 200 W Arbor Dr, San Diego, CA, 92103, USA.
authors.forename: Shaun R
authors.initials: SR
authors.lastname: Best
authors.affiliation: Department of Radiology, Naval Medical Center San Diego, San Diego, USA.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Marks
authors.affiliation: Department of Radiology, Naval Medical Center San Diego, San Diego, USA.
authors.forename: Jared
authors.initials: J
authors.lastname: Heimbigner
authors.affiliation: Department of Urology, University of California San Diego School of Medicine, San Diego, USA.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Kane
authors.affiliation: Department of Urology, University of California San Diego School of Medicine, San Diego, USA.
authors.forename: J Kellogg
authors.initials: JK
authors.lastname: Parsons
authors.affiliation: Department of Radiology, University of California San Diego School of Medicine, 200 W Arbor Dr, San Diego, CA, 92103, USA.
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Kuperman
authors.affiliation: Department of Radiology, University of California San Diego School of Medicine, 200 W Arbor Dr, San Diego, CA, 92103, USA.
authors.forename: Hauke
authors.initials: H
authors.lastname: Bartsch
authors.affiliation: Department of Radiology, University of California San Diego School of Medicine, 200 W Arbor Dr, San Diego, CA, 92103, USA.
authors.forename: Rahul S
authors.initials: RS
authors.lastname: Desikan
authors.affiliation: Department of Radiology, University of California San Diego School of Medicine, 200 W Arbor Dr, San Diego, CA, 92103, USA.
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Rakow-Penner
authors.affiliation: Department of Urology, University of Texas San Antonio School of Medicine, San Antonio, USA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Liss
authors.affiliation: Department of Radiology, University of California Los Angeles Geffen School of Medicine, Los Angeles, USA.
authors.forename: Daniel J A
authors.initials: DJ
authors.lastname: Margolis
authors.affiliation: Department of Radiology, University of California Los Angeles Geffen School of Medicine, Los Angeles, USA.
authors.forename: Steven S
authors.initials: SS
authors.lastname: Raman
authors.affiliation: Department of Pathology, University of California San Diego School of Medicine, San Diego, USA.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Shabaik
authors.affiliation: Department of Radiology, University of California San Diego School of Medicine, 200 W Arbor Dr, San Diego, CA, 92103, USA.|Department of Neurosciences, University of California San Diego School of Medicine, San Diego, USA.
authors.forename: Anders M
authors.initials: AM
authors.lastname: Dale
authors.affiliation: Department of Radiology, University of California San Diego School of Medicine, 200 W Arbor Dr, San Diego, CA, 92103, USA. dkarow@ucsd.edu.
authors.forename: David S
authors.initials: DS
authors.lastname: Karow
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D003287:Contrast Media; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D012680:Sensitivity and Specificity; D047368:Tumor Burden
chemical_list: D003287:Contrast Media
keywords: Diffuse weighted imaging; Prostate MRI; Prostate cancer; Prostate diffusion imaging; Restriction spectrum imaging