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MAGNETIC RESONANCE IMAGING FOR NONINVASIVE ANALYSIS OF FAT STORAGE IN MIGRATORY BIRDS

Wirestam, Ronnie LU ; Fagerlund, Timmy; Rosén, Mikael LU and Hedenström, Anders LU (2008) In The Auk 125(4). p.965-971
Abstract
Many bird species migrate long distances without any food intake and must optimize storage of energy with respect to minimization of aerodynamic drag. To contribute to the understanding of this issue, we investigated, by magnetic resonance imaging (MRI), spatial distributions of body fat during the accumulation process before migration. We collected data from 12 Lesser Whitethroats (Sylvia curruca), 9 European Robins (Erithacus rubecula), 8 Blackcaps (Sylvia atricapilla), and 5 Willow Warblers (Phylloscopus trochilus). On average, each bird was examined 3.2 times. Adipose tissue was Visualized using T1-weighted spin-echo MRI at 1.5 T. Fat-containing pixels were identified by an image-segmentation procedure. Data were analyzed with respect... (More)
Many bird species migrate long distances without any food intake and must optimize storage of energy with respect to minimization of aerodynamic drag. To contribute to the understanding of this issue, we investigated, by magnetic resonance imaging (MRI), spatial distributions of body fat during the accumulation process before migration. We collected data from 12 Lesser Whitethroats (Sylvia curruca), 9 European Robins (Erithacus rubecula), 8 Blackcaps (Sylvia atricapilla), and 5 Willow Warblers (Phylloscopus trochilus). On average, each bird was examined 3.2 times. Adipose tissue was Visualized using T1-weighted spin-echo MRI at 1.5 T. Fat-containing pixels were identified by an image-segmentation procedure. Data were analyzed with respect to (1) fat distribution within the body, (2) relationship between frontal surface area and fat mass increase, (3) fat mass increase in comparison with increase in total body mass, and (4) fat mass in relation to standardized visual classification of fat deposits. Fat increase was reflected by a larger frontal area, though adipose tissue was not deposited equally along the length of the bird. Slices with largest frontal area showed relatively low fractions of fat. Frontal area increased less than expected from conventional geometrical models, which indicates that the body shape is altered. The increase in total body mass was generally higher than the total fat mass increase, which indicates that other tissue, most likely flight muscle, can metabolize rapidly in correlation with fat accumulation. In Blackcap, total fat mass was not linearly related to standardized fat-deposit classes. Received 31 August 2007, accepted 7 June 2008. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
migratory birds, migration, magnetic resonance imaging, fuel load, adipose tissue, fat storage
in
The Auk
volume
125
issue
4
pages
965 - 971
publisher
BioOne
external identifiers
  • wos:000261648400023
  • scopus:67749144826
ISSN
0004-8038
DOI
10.1525/auk.2009.07145
language
English
LU publication?
yes
id
34d29a34-3ad7-4e19-a46b-b786cb166c7a (old id 1383991)
date added to LUP
2009-05-08 15:14:37
date last changed
2017-05-28 03:55:47
@article{34d29a34-3ad7-4e19-a46b-b786cb166c7a,
  abstract     = {Many bird species migrate long distances without any food intake and must optimize storage of energy with respect to minimization of aerodynamic drag. To contribute to the understanding of this issue, we investigated, by magnetic resonance imaging (MRI), spatial distributions of body fat during the accumulation process before migration. We collected data from 12 Lesser Whitethroats (Sylvia curruca), 9 European Robins (Erithacus rubecula), 8 Blackcaps (Sylvia atricapilla), and 5 Willow Warblers (Phylloscopus trochilus). On average, each bird was examined 3.2 times. Adipose tissue was Visualized using T1-weighted spin-echo MRI at 1.5 T. Fat-containing pixels were identified by an image-segmentation procedure. Data were analyzed with respect to (1) fat distribution within the body, (2) relationship between frontal surface area and fat mass increase, (3) fat mass increase in comparison with increase in total body mass, and (4) fat mass in relation to standardized visual classification of fat deposits. Fat increase was reflected by a larger frontal area, though adipose tissue was not deposited equally along the length of the bird. Slices with largest frontal area showed relatively low fractions of fat. Frontal area increased less than expected from conventional geometrical models, which indicates that the body shape is altered. The increase in total body mass was generally higher than the total fat mass increase, which indicates that other tissue, most likely flight muscle, can metabolize rapidly in correlation with fat accumulation. In Blackcap, total fat mass was not linearly related to standardized fat-deposit classes. Received 31 August 2007, accepted 7 June 2008.},
  author       = {Wirestam, Ronnie and Fagerlund, Timmy and Rosén, Mikael and Hedenström, Anders},
  issn         = {0004-8038},
  keyword      = {migratory birds,migration,magnetic resonance imaging,fuel load,adipose tissue,fat storage},
  language     = {eng},
  number       = {4},
  pages        = {965--971},
  publisher    = {BioOne},
  series       = {The Auk},
  title        = {MAGNETIC RESONANCE IMAGING FOR NONINVASIVE ANALYSIS OF FAT STORAGE IN MIGRATORY BIRDS},
  url          = {http://dx.doi.org/10.1525/auk.2009.07145},
  volume       = {125},
  year         = {2008},
}