TY - JOUR
T1 - Quantitative diffusion tensor imaging analysis does not distinguish pediatric canines with mucopolysaccharidosis i from control canines
AU - Middleton, Dana M.
AU - Li, Jonathan Y.
AU - Chen, Steven D.
AU - White, Leonard E.
AU - Dickson, Patricia I.
AU - Matthew Ellinwood, N.
AU - Provenzale, James M.
N1 - Funding Information:
This work was supported by Patricia Dickson’s following grant: National Institutes of Health grant R01 NS085381, National Institute for Neurological Disorders and Stroke. James M Provenzale and Steven Chen are paid consultants on this grant.
Funding Information:
Work was performed at the Duke Center for In Vivo Microscopy, a national Biomedical Technology Resource Center supported by the National Institutes of Health/ National Center for Research Resources/National Institutes of Biomedical Imaging and Bioengineering (grant P41 EB015897).
Publisher Copyright:
© 2017 SAGE Publications.
PY - 2017/10/1
Y1 - 2017/10/1
N2 - Purpose We compared fractional anisotropy and radial diffusivity measurements between pediatric canines affected with mucopolysaccharidosis I and pediatric control canines. We hypothesized that lower fractional anisotropy and higher radial diffusivity values, consistent with dysmyelination, would be present in the mucopolysaccharidosis I cohort. Methods Six canine brains, three affected with mucopolysaccharidosis I and three unaffected, were euthanized at 7 weeks and imaged using a 7T small-animal magnetic resonance imaging system. Average fractional anisotropy and radial diffusivity values were calculated for four white-matter regions based on 100 regions of interest per region per specimen. A 95% confidence interval was calculated for each mean value. Results No difference was seen in fractional anisotropy or radial diffusivity values between mucopolysaccharidosis affected and unaffected brains in any region. In particular, the 95% confidence intervals for mucopolysaccharidosis affected and unaffected canines frequently overlapped for both fractional anisotropy and radial diffusivity measurements. In addition, in some brain regions a large range of fractional anisotropy and radial diffusivity values were seen within the same cohort. Conclusion The fractional anisotropy and radial diffusivity values of white matter did not differ between pediatric mucopolysaccharidosis affected canines and pediatric control canines. Possible explanations include: (a) a lack of white matter tissue differences between mucopolysaccharidosis affected and unaffected brains at early disease stages; (b) diffusion tensor imaging does not detect any existing differences; (c) inflammatory processes such as astrogliosis produce changes that offset the decreased fractional anisotropy values and increased radial diffusivity values that are expected in dysmyelination; and (d) our sample size was insufficient to detect differences. Further studies correlating diffusion tensor imaging findings to histology are warranted.
AB - Purpose We compared fractional anisotropy and radial diffusivity measurements between pediatric canines affected with mucopolysaccharidosis I and pediatric control canines. We hypothesized that lower fractional anisotropy and higher radial diffusivity values, consistent with dysmyelination, would be present in the mucopolysaccharidosis I cohort. Methods Six canine brains, three affected with mucopolysaccharidosis I and three unaffected, were euthanized at 7 weeks and imaged using a 7T small-animal magnetic resonance imaging system. Average fractional anisotropy and radial diffusivity values were calculated for four white-matter regions based on 100 regions of interest per region per specimen. A 95% confidence interval was calculated for each mean value. Results No difference was seen in fractional anisotropy or radial diffusivity values between mucopolysaccharidosis affected and unaffected brains in any region. In particular, the 95% confidence intervals for mucopolysaccharidosis affected and unaffected canines frequently overlapped for both fractional anisotropy and radial diffusivity measurements. In addition, in some brain regions a large range of fractional anisotropy and radial diffusivity values were seen within the same cohort. Conclusion The fractional anisotropy and radial diffusivity values of white matter did not differ between pediatric mucopolysaccharidosis affected canines and pediatric control canines. Possible explanations include: (a) a lack of white matter tissue differences between mucopolysaccharidosis affected and unaffected brains at early disease stages; (b) diffusion tensor imaging does not detect any existing differences; (c) inflammatory processes such as astrogliosis produce changes that offset the decreased fractional anisotropy values and increased radial diffusivity values that are expected in dysmyelination; and (d) our sample size was insufficient to detect differences. Further studies correlating diffusion tensor imaging findings to histology are warranted.
KW - Mucopolysaccharidosis
KW - canine
KW - diffusion tensor imaging
KW - fractional anisotropy
KW - radial diffusivity
UR - http://www.scopus.com/inward/record.url?scp=85029519031&partnerID=8YFLogxK
U2 - 10.1177/1971400917718844
DO - 10.1177/1971400917718844
M3 - Article
C2 - 28703635
AN - SCOPUS:85029519031
VL - 30
SP - 454
EP - 460
JO - Neuroradiology Journal
JF - Neuroradiology Journal
SN - 1971-4009
IS - 5
ER -