Format

Send to

Choose Destination
Acad Radiol. 2016 Jun;23(6):704-11. doi: 10.1016/j.acra.2016.02.003. Epub 2016 Mar 15.

Prostate Cancer Detection Using Computed Very High b-value Diffusion-weighted Imaging: How High Should We Go?

Author information

1
Department of Radiology, NYU School of Medicine, NYU Langone Medical Center, 550 First Avenue, New York, NY 10016. Electronic address: Andrew.Rosenkrantz@nyumc.org.
2
Department of Radiology, NYU School of Medicine, NYU Langone Medical Center, 550 First Avenue, New York, NY 10016.
3
Department of Pathology, NYU School of Medicine, NYU Langone Medical Center, New York, New York.
4
Department of Urology, Division of Urologic Oncology, NYU School of Medicine, NYU Langone Medical Center, New York, New York.

Abstract

RATIONALE AND OBJECTIVES:

The aim of this study was to assess prostate cancer detection using a broad range of computed b-values up to 5000 s/mm(2).

MATERIALS AND METHODS:

This retrospective Health Insurance Portability and Accountability Act-compliant study was approved by an institutional review board with consent waiver. Forty-nine patients (63 ± 8 years) underwent 3T prostate magnetic resonance imaging before prostatectomy. Examinations included diffusion-weighted imaging (DWI) with b-values of 50 and 1000 s/mm(2). Seven computed DWI image sets (b-values: 1000, 1500, 2000, 2500, 3000, 4000, and 5000 s/mm(2)) were generated by mono-exponential fit. Two blinded radiologists (R1 [attending], R2 [fellow]) independently evaluated diffusion weighted image sets for image quality and dominant lesion location. A separate unblinded radiologist placed regions of interest to measure tumor-to-peripheral zone (PZ) contrast. Pathologic findings from prostatectomy served as reference standard. Measures were compared between b-values using the Jonckheere-Terpstra trend test, Spearman correlation coefficient, and generalized estimating equations based on logistic regression for correlated data.

RESULTS:

As b-value increased, tumor-to-PZ contrast and benign prostate suppression for both readers increased (r = +0.65 to +0.71, P ≤ 0.001), whereas anatomic clarity, visualization of the capsule, and visualization of peripheral-transition zone edge decreased (r = -0.69 to -0.75, P ≤ 0.003). Sensitivity for tumor was highest for R1 at b1500-3000 (84%-88%) and for R2 at b1500-2500 (70%-76%). Sensitivities for both pathologic outcomes were lower for both readers at both b1000 and the highest computed b-values. Sensitivity for Gleason >6 tumor was highest for R1 at b1500-3000 (90%-93%) and for R2 at 1500-2500 (78%-80%). The positive predictive value for tumor for R1 was similar from b1000 to 4000 (93%-98%) and for R2 was similar from b1500 to 4000 (88%-94%).

CONCLUSIONS:

Computed b-values in the range of 1500-2500 s/mm(2) (but not higher) were optimal for prostate cancer detection; b-values of 1000 or 3000-5000 exhibited overall lower performance.

KEYWORDS:

Prostate; diffusion magnetic resonance imaging; imaging; magnetic resonance imaging; neoplasms

PMID:
26992738
DOI:
10.1016/j.acra.2016.02.003
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center