title: Accuracy and reproducibility of adipose tissue measurements in young infants by whole body magnetic resonance imaging.
abstract: OBJECTIVE
  MR might be well suited to obtain reproducible and accurate measures of fat tissues in infants. This study evaluates MR-measurements of adipose tissue in young infants in vitro and in vivo.
  
  
  METHODS
  MR images of ten phantoms simulating subcutaneous fat of an infant's torso were obtained using a 1.5T MR scanner with and without simulated breathing. Scans consisted of a cartesian water-suppression turbo spin echo (wsTSE) sequence, and a PROPELLER wsTSE sequence. Fat volume was quantified directly and by MR imaging using k-means clustering and threshold-based segmentation procedures to calculate accuracy in vitro. Whole body MR was obtained in sleeping young infants (average age 67±30 days). This study was approved by the local review board. All parents gave written informed consent. To obtain reproducibility in vivo, cartesian and PROPELLER wsTSE sequences were repeated in seven and four young infants, respectively. Overall, 21 repetitions were performed for the cartesian sequence and 13 repetitions for the PROPELLER sequence.
  
  
  RESULTS
  In vitro accuracy errors depended on the chosen segmentation procedure, ranging from 5.4% to 76%, while the sequence showed no significant influence. Artificial breathing increased the minimal accuracy error to 9.1%. In vivo reproducibility errors for total fat volume of the sleeping infants ranged from 2.6% to 3.4%. Neither segmentation nor sequence significantly influenced reproducibility.
  
  
  CONCLUSIONS
  With both cartesian and PROPELLER sequences an accurate and reproducible measure of body fat was achieved. Adequate segmentation was mandatory for high accuracy.
authors.affiliation: Department of Neuroradiology, Technische Universität München, Munich, Germany.
authors.forename: Jan Stefan
authors.initials: JS
authors.lastname: Bauer
authors.affiliation: Department of Radiology, Technische Universität München, Munich, Germany.
authors.forename: Peter Benjamin
authors.initials: PB
authors.lastname: Noël
authors.affiliation: Else Kröner-Fresenius-Center for Nutritional Medicine, Technische Universität München, Munich, Germany.
authors.forename: Christiane
authors.initials: C
authors.lastname: Vollhardt
authors.affiliation: Else Kröner-Fresenius-Center for Nutritional Medicine, Technische Universität München, Munich, Germany.
authors.forename: Daniela
authors.initials: D
authors.lastname: Much
authors.affiliation: Department of Radiology, Technische Universität München, Munich, Germany.
authors.forename: Saliha
authors.initials: S
authors.lastname: Degirmenci
authors.affiliation: Else Kröner-Fresenius-Center for Nutritional Medicine, Technische Universität München, Munich, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Brunner
authors.affiliation: Department of Radiology, Technische Universität München, Munich, Germany.
authors.forename: Ernst Josef
authors.initials: EJ
authors.lastname: Rummeny
authors.affiliation: Else Kröner-Fresenius-Center for Nutritional Medicine, Technische Universität München, Munich, Germany.
authors.forename: Hans
authors.initials: H
authors.lastname: Hauner
mesh_terms: D000273:Adipose Tissue / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D011446:Prospective Studies; D015203:Reproducibility of Results; D051598:Whole Body Imaging / Q000379:methods*