Comparison of fitting methods and b-value sampling strategies for intravoxel incoherent motion in breast cancer.

Publication Type	Academic Article
Authors	Cho G, Moy L, Zhang J, Baete S, Lattanzi R, Moccaldi M, Babb J, Kim S, Sodickson D, Sigmund E
Journal	Magn Reson Med
Volume	74
Issue	4
Pagination	1077-85
Date Published	10/09/2014
ISSN	1522-2594
Keywords	Breast Neoplasms, Diffusion Magnetic Resonance Imaging, Image Processing, Computer-Assisted
Abstract	PURPOSE: To compare fitting methods and sampling strategies, including the implementation of an optimized b-value selection for improved estimation of intravoxel incoherent motion (IVIM) parameters in breast cancer. METHODS: Fourteen patients (age, 48.4 ± 14.27 years) with cancerous lesions underwent 3 Tesla breast MRI examination for a HIPAA-compliant, institutional review board approved diffusion MR study. IVIM biomarkers were calculated using "free" versus "segmented" fitting for conventional or optimized (repetitions of key b-values) b-value selection. Monte Carlo simulations were performed over a range of IVIM parameters to evaluate methods of analysis. Relative bias values, relative error, and coefficients of variation (CV) were obtained for assessment of methods. Statistical paired t-tests were used for comparison of experimental mean values and errors from each fitting and sampling method. RESULTS: Comparison of the different analysis/sampling methods in simulations and experiments showed that the "segmented" analysis and the optimized method have higher precision and accuracy, in general, compared with "free" fitting of conventional sampling when considering all parameters. Regarding relative bias, IVIM parameters fp and Dt differed significantly between "segmented" and "free" fitting methods. CONCLUSION: IVIM analysis may improve using optimized selection and "segmented" analysis, potentially enabling better differentiation of breast cancer subtypes and monitoring of treatment.
DOI	10.1002/mrm.25484
PubMed ID	25302780
PubMed Central ID	PMC4439397