Abstract

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.

Links

Publisher Full Text

Authors

Rosenkrantz AB, Sigmund EE, Johnson G, Babb JS, Mussi TC, Melamed J, Taneja SS, Lee VS, Jensen JH

Institution

Department of Radiology, New York University Langone Medical Center, 550 First Ave, TCH-HW202, New York, NY 10016, USA. Andrew.Rosenkrantz@nyumc.org

Source

Radiology 264:1 2012 Jul pg 126-35

MeSH

Aged
Analysis of Variance
Bayes Theorem
Biopsy
Diagnosis, Differential
Diffusion Magnetic Resonance Imaging
Feasibility Studies
Humans
Image Interpretation, Computer-Assisted
Male
Neoplasm Grading
Prostatic Neoplasms
ROC Curve
Retrospective Studies

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

22550312