title: Organ volume measurements: comparison between MRI and autopsy findings in infants following sudden unexpected death.
abstract: OBJECTIVE
  To assess the accuracy of a semiautomated 3D volume reconstruction method for organ volume measurement by postmortem MRI.
  
  
  METHODS
  This prospective study was approved by the institutional review board and the infants' parents gave their consent. Postmortem MRI was performed in 16 infants (1 month to 1 year of age) at 1.5 T within 48 h of their sudden death. Virtual organ volumes were estimated using the Myrian software. Real volumes were recorded at autopsy by water displacement. The agreement between virtual and real volumes was quantified following the Bland and Altman's method.
  
  
  RESULTS
  There was a good agreement between virtual and real volumes for brain (mean difference: -0.03% (-13.6 to +7.1)), liver (+8.3% (-9.6 to +26.2)) and lungs (+5.5% (-26.6 to +37.6)). For kidneys, spleen and thymus, the MRI/autopsy volume ratio was close to 1 (kidney: 0.87±0.1; spleen: 0.99±0.17; thymus: 0.94±0.25), but with a less good agreement. For heart, the MRI/real volume ratio was 1.29±0.76, possibly due to the presence of residual blood within the heart. The virtual volumes of adrenal glands were significantly underestimated (p=0.04), possibly due to their very small size during the first year of life. The percentage of interobserver and intraobserver variation was lower or equal to 10%, but for thymus (15.9% and 12.6%, respectively) and adrenal glands (69% and 25.9%).
  
  
  CONCLUSIONS
  Virtual volumetry may provide significant information concerning the macroscopic features of the main organs and help pathologists in sampling organs that are more likely to yield histological findings.
authors.affiliation: Department of Pediatric Radiology, Montpellier University Hospital, Montpellier, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Prodhomme
authors.forename: Fabienne
authors.initials: F
authors.lastname: Seguret
authors.forename: Laurent
authors.initials: L
authors.lastname: Martrille
authors.forename: Odile
authors.initials: O
authors.lastname: Pidoux
authors.forename: Gilles
authors.initials: G
authors.lastname: Cambonie
authors.forename: Alain
authors.initials: A
authors.lastname: Couture
authors.forename: Caroline
authors.initials: C
authors.lastname: Rouleau
mesh_terms: D001344:Autopsy; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D008297:Male; D009929:Organ Size; D011446:Prospective Studies; D013398:Sudden Infant Death / Q000473:pathology*