title: Reversible MR changes in the cat brain after cerebral fat embolism induced by triolein emulsion.
abstract: OBJECTIVE
  Clinical cerebral-fat embolism shows both reversible and irreversible changes. We used MR imaging to investigate the reversibility of embolized lesions induced with a fat-emulsion technique and to evaluate the histologic findings.
  
  
  METHODS
  A fat emulsion was made with 0.05 mL of triolein and 20 mL of normal saline and vigorous to-and-fro movement through a three-way stopcock. In 50 cats, the internal carotid artery was infused with the fat emulsion. Cats were divided into six groups on the basis of time delay after embolization: 1 hour; 1 and 4 days; and 1, 2, and 3 weeks. MR imaging and histologic examination were performed at these times.
  
  
  RESULTS
  Embolized lesions were hyperintense on T2-weighted images, isointense or mildly hyperintense on diffusion-weighted images, isointense on apparent diffusion coefficient maps, and enhancing on gadolinium-enhanced T1-weighted images at 1 hour. These MR imaging findings were less evident at day 1 and reverted to normal after day 4 (isointense on all images). Electron microscopy showed minimal findings in the cortical lesion in groups 1 and 2 (group 1 at 1 hour and group 2 at 1 hour and 1 day). Light microscopic findings revealed evidence of necrosis-small focal gliosis and demyelination in the periventricular white matter-in only one cat. The number of intravascular fat globules was not significantly different between groups, as visualized by oil red O staining.
  
  
  CONCLUSIONS
  Cerebral-fat embolism induced by a triolein emulsion revealed reversible MR findings and minimal histologic findings.
authors.affiliation: Pusan National University College of Medicine, Pusan National University Hospital, Department of Radiology, Pusan, South Korea.
authors.forename: Hak J
authors.initials: HJ
authors.lastname: Kim
authors.forename: Chang H
authors.initials: CH
authors.lastname: Lee
authors.forename: Hae G
authors.initials: HG
authors.lastname: Kim
authors.forename: Sang D
authors.initials: SD
authors.lastname: Lee
authors.forename: Suk M
authors.initials: SM
authors.lastname: Son
authors.forename: Yong W
authors.initials: YW
authors.lastname: Kim
authors.forename: Choong K
authors.initials: CK
authors.lastname: Eun
authors.forename: Seung M
authors.initials: SM
authors.lastname: Kim
mesh_terms: D000818:Animals; D001921:Brain / Q000473:pathology*; D002415:Cats; D004620:Embolism, Fat / Q000139:chemically induced / Q000473:pathology*; D004655:Emulsions / Q000008:administration & dosage; D005260:Female; D020766:Intracranial Embolism / Q000139:chemically induced / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D013997:Time Factors; D014304:Triolein / Q000008:administration & dosage
chemical_list: D004655:Emulsions; D014304:Triolein