Comparison of different mathematical models of diffusion-weighted prostate MR imaging

Magn Reson Imaging. 2012 Dec;30(10):1468-74. doi: 10.1016/j.mri.2012.04.025. Epub 2012 Jul 20.

Abstract

Purpose: To evaluate which mathematical model (monoexponential, biexponential, statistical, kurtosis) fits best to the diffusion-weighted signal in prostate magnetic resonance imaging (MRI).

Materials and methods: 24 prostate 3-T MRI examinations of young volunteers (YV, n=8), patients with biopsy proven prostate cancer (PC, n=8) and an aged matched control group (AC, n=8) were included. Diffusion-weighted imaging was performed using 11 b-values ranging from 0 to 800 s/mm(2).

Results: Monoexponential apparent diffusion coefficient (ADC) values were significantly (P<.001) lower in the peripheral (PZ) zone (1.18±0.16 mm(2)/s) and the central (CZ) zone (0.73±0.13 mm(2)/s) of YV compared to AC (PZ 1.92±0.17 mm(2)/s; CZ 1.35±0.21 mm(2)/s). In PC ADC(mono) values (0.61±0.06 mm(2)/s) were significantly (P<.001) lower than in the peripheral of central zone of AC. Using the statistical analysis (Akaike information criteria) in YV most pixels were best described by the biexponential model (82%), the statistical model, respectively kurtosis (93%) each compared to the monoexponential model. In PC the majority of pixels was best described by the monoexponential model (57%) compared to the biexponential model.

Conclusion: Although a more complex model might provide a better fitting when multiple b-values are used, the monoexponential analyses for ADC calculation in prostate MRI is sufficient to discriminate prostate cancer from normal tissue using b-values ranging from 0 to 800 s/mm(2).

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Aged
  • Computer Simulation
  • Diffusion Magnetic Resonance Imaging / methods*
  • Humans
  • Image Processing, Computer-Assisted / methods
  • Male
  • Middle Aged
  • Models, Statistical
  • Models, Theoretical
  • Normal Distribution
  • Prostate / pathology*
  • Prostatic Neoplasms / pathology
  • Reproducibility of Results
  • Signal Processing, Computer-Assisted
  • Software