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Optimization of b‐value distribution for biexponential diffusion‐weighted MR imaging of normal prostate
Author(s) -
Jambor Ivan,
Merisaari Harri,
Aronen Hannu J.,
Järvinen Jukka,
Saunavaara Jani,
Kauko Tommi,
Borra Ronald,
Pesola Marko
Publication year - 2014
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.24271
Subject(s) - diffusion mri , nuclear medicine , medicine , distribution (mathematics) , prostate , nuclear magnetic resonance , magnetic resonance imaging , radiology , mathematics , physics , mathematical analysis , cancer
Purpose To determine the optimal b‐value distribution for biexponential diffusion‐weighted imaging (DWI) of normal prostate using both a computer modeling approach and in vivo measurements. Materials and Methods Optimal b‐value distributions for the fit of three parameters (fast diffusion Df , slow diffusion Ds , and fraction of fast diffusion f ) were determined using Monte‐Carlo simulations. The optimal b‐value distribution was calculated using four individual optimization methods. Eight healthy volunteers underwent four repeated 3 Tesla prostate DWI scans using both 16 equally distributed b‐values and an optimized b‐value distribution obtained from the simulations. The b‐value distributions were compared in terms of measurement reliability and repeatability using Shrout‐Fleiss analysis. Results Using low noise levels, the optimal b‐value distribution formed three separate clusters at low (0–400 s/mm 2 ), mid‐range (650–1200 s/mm 2 ), and high b‐values (1700–2000 s/mm 2 ). Higher noise levels resulted into less pronounced clustering of b‐values. The clustered optimized b‐value distribution demonstrated better measurement reliability and repeatability in Shrout‐Fleiss analysis compared with 16 equally distributed b‐values. Conclusion The optimal b‐value distribution was found to be a clustered distribution with b‐values concentrated in the low, mid, and high ranges and was shown to improve the estimation quality of biexponential DWI parameters of in vivo experiments. J. Magn. Reson. Imaging 2014;39:1213–1222 . © 2013 Wiley Periodicals, Inc .