Purpose:To assess the feasibility of diffusional kurtosis (DK) imaging for distinguishing benign from malignant regions, as well as low- from high-grade malignant regions, within the peripheral zone (PZ) of the prostate in comparison with standard diffusion-weighted (DW) imaging.
Materials and Methods: The institutional review board approved this retrospective HIPAA-compliant study and waived informed consent. Forty-seven patients with prostate cancer underwent 3-T magnetic resonance imaging by using a pelvic phased-array coil and DW imaging (maximum b value, 2000 sec/mm2). Parametric maps were obtained for apparent diffusion coefficient (ADC); the metric DK (K), which represents non-Gaussian diffusion behavior; and corrected diffusion (D) that accounts for this non-Gaussianity. Two radiologists reviewed these maps and measured ADC, D, and K in sextants positive for cancer at biopsy. Data were analyzed by using mixed-model analysis of variance and receiver operating characteristic curves.
Results: Seventy sextants exhibited a Gleason score of 6; 51 exhibited a Gleason score of 7 or 8. K was significantly greater in cancerous sextants than in benign PZ (0.96 ± 0.24 vs 0.57 ± 0.07, P < .001), as well as in cancerous sextants with higher rather than lower Gleason score (1.05 ± 0.26 vs 0.89 ± 0.20, P < .001). K showed significantly greater sensitivity for differentiating cancerous sextants from benign PZ than ADC or D (93.3% vs 78.5% and 83.5%, respectively; P < .001), with equal specificity (95.7%, P > .99). K exhibited significantly greater sensitivity for differentiating sextants with low- and high-grade cancer than ADC or D (68.6% vs 51.0% and 49.0%, respectively; P ≤ .004) but with decreased specificity (70.0% vs 81.4% and 82.9%, respectively; P ≤ .023). K had significantly greater area under the curve for differentiating sextants with low- and high-grade cancer than ADC (0.70 vs 0.62, P = .010). Relative contrast between cancerous sextants and benign PZ was significantly greater for D or K than ADC (0.25 ± 0.14 and 0.24 ± 0.13, respectively, vs 0.18 ± 0.10; P < .001).
Conclusion: Preliminary findings suggest increased value for DK imaging compared with standard DW imaging in prostate cancer assessment.
Written by:
Rosenkrantz AB, Sigmund EE, Johnson G, Babb JS, Mussi TC, Melamed J, Taneja SS, Lee VS, Jensen JH. Are you the author?
Department of Radiology, Department of Pathology, and Division of Urologic Oncology, Department of Urology, New York University Langone Medical Center, 550 First Ave, TCH-HW202, New York, NY 10016.
Reference: Radiology. 2012 May 1. Epub ahead of print.
doi: 10.1148/radiol.12112290
PubMed Abstract
PMID: 22550312
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