Open AccessWhole‐brain atrophy assessed by proportional‐ versus registration‐based pipelines from 3T MRI in multiple sclerosis
Author(s) -
Hemond Christopher C.,
Chu Renxin,
Tummala Subhash,
Tauhid Shahamat,
Healy Brian C.,
Bakshi Rohit
Publication year - 2018
Publication title -
brain and behavior
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.915
H-Index - 41
ISSN - 2162-3279
DOI - 10.1002/brb3.1068
Subject(s) - atrophy , multiple sclerosis , expanded disability status scale , medicine , fluid attenuated inversion recovery , magnetic resonance imaging , brain size , nuclear medicine , white matter , neuroimaging , cardiology , radiology , psychiatry
Background and Purpose Whole‐brain atrophy is a standard outcome measure in multiple sclerosis ( MS ) clinical trials as assessed by various software tools. The effect of processing method on the validity of such data obtained from high‐resolution 3T MRI is not known. We compared two commonly used methods of quantifying whole‐brain atrophy. Methods Three‐dimensional T1‐weighted and FLAIR images were obtained at 3T in MS ( n = 61) and normal control ( NC , n = 30) groups. Whole‐brain atrophy was assessed by two automated pipelines: (a) SPM 8 to derive brain parenchymal fraction ( BPF , proportional‐based method); (b) SIENAX to derive normalized brain parenchymal volume ( BPV , registration method). We assessed agreement between BPF and BPV , as well their relationship to Expanded Disability Status Scale ( EDSS ) score, timed 25‐foot walk (T25 FW ), cognition, and cerebral T2 ( FLAIR ) lesion volume (T2 LV ). Results Brain parenchymal fraction and BPV showed only partial agreement ( r = 0.73) in the MS group, and r = 0.28 in NC . Both methods showed atrophy in MS versus NC ( BPF p < 0.01, BPV p < 0.05). Within MS group comparisons, BPF ( p < 0.05) but not BPV ( p > 0.05) correlated with EDSS score. BPV ( p = 0.03) but not BPF ( p = 0.08) correlated with T25 FW . Both metrics correlated with T2 LV ( p < 0.05) and cognitive subscales. BPF ( p < 0.05) but not BPV ( p > 0.05) showed lower brain volume in cognitively impaired ( n = 23) versus cognitively preserved ( n = 38) patients. However, direct comparisons of BPF and BPV sensitivities to atrophy and clinical correlations were not statistically significant. Conclusion Whole‐brain atrophy metrics may not be interchangeable between proportional‐ and registration‐based automated pipelines from 3T MRI in patients with MS .