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Validation of functional diffusion maps (fDMs) as a biomarker for human glioma cellularity
Author(s) -
Ellingson Benjamin M.,
Malkin Mark G.,
Rand Scott D.,
Connelly Jennifer M.,
Quinsey Carolyn,
LaViolette Pete S.,
Bedekar Devyani P.,
Schmainda Kathleen M.
Publication year - 2010
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.22068
Subject(s) - white matter , medicine , nuclear medicine , diffusion mri , imaging biomarker , glioma , confidence interval , biopsy , voxel , biomarker , radiology , pathology , magnetic resonance imaging , chemistry , cancer research , biochemistry
Purpose: To present comprehensive examinations of the assumptions made in functional diffusion map (fDM) analyses and provide a biological basis for fDM classification. Materials and Methods: Sixty‐nine patients with gliomas were enrolled in this study. To determine the sensitivity of apparent diffusion coefficients (ADCs) to cellularity, cell density from stereotactic biopsy specimens was correlated with preoperative ADC maps. For definition of ADC thresholds used for fDMs, the 95% confidence intervals (CI) for changes in voxel‐wise ADC measurements in normal appearing tissue was analyzed. The sensitivity and specificity to progressing disease was examined using both radiographic and neurological criteria. Results: Results support the hypothesis that ADC is inversely proportional to cell density with a sensitivity of 1.01 × 10 −7 [mm 2 /s]/[nuclei/mm 2 ]. The 95% CI for white matter = 0.25 × 10 −3 mm 2 /s, gray matter = 0.31 × 10 −3 mm 2 /s, a mixture of white and gray matter = 0.40 × 10 −3 mm 2 /s, and a mixture of white matter, gray matter, and cerebrospinal fluid = 0.75 × 10 −3 mm 2 /s. Application of these measurements as ADC thresholds produce varying levels of sensitivity and specificity to disease progression, which were all significantly better than chance. Conclusion: This study suggests fDMs are valid biomarkers for brain tumor cellularity. J. Magn. Reson. Imaging 2010;31:538–548. ©2010 Wiley‐Liss, Inc.