title: Experimental cerebral fat embolism: embolic effects of triolein and oleic acid depicted by MR imaging and electron microscopy.
abstract: OBJECTIVE
  In fat embolism, free fatty acid is more toxic than neutral fat in terms of tissue damage. We evaluated the hyperacute embolic effects of triolein and oleic acid in cat brains by using MR imaging and electron microscopy.
  
  
  METHODS
  T2-weighted imaging, diffusion-weighted imaging, and contrast-enhanced T1-weighted imaging were performed in cat brains after the injection of triolein (group 1, n = 8) or oleic acid (group 2, n = 10) into the internal carotid artery. MR images were quantitatively assessed by comparing the signal intensity ratios of the lesions with their counterparts on T2-weighted images, apparent diffusion coefficient (ADC) maps, and contrast-enhanced T1-weighted images. Electron microscopic findings in group 1 were compared with those in group 2.
  
  
  RESULTS
  Qualitatively, MR images revealed two types of lesions. Type 1 lesions were hyperintense on diffusion-weighted images and hypointense on ADC maps. Type 2 lesions were isointense or mildly hyperintense on diffusion-weighted images and isointense on ADC maps. Quantitatively, the signal intensity ratios of type 1 lesions in group 2 specimens were significantly higher on T2-weighted images (P =.013)/(P =.027) and lower on ADC maps compared with those of group 1. Electron microscopy of type 1 lesions in both groups revealed more prominent widening of the perivascular space and swelling of the neural cells in group 2, in contrast to notable endothelial defects in group 1.
  
  
  CONCLUSIONS
  MR and electron microscopic data on cerebral fat embolism induced by either triolein or oleic acid revealed characteristics suggestive of both vasogenic and cytotoxic edema in the hyperacute stage. Tissue damage appeared more severe in the oleic acid group than in the triolein group.
authors.affiliation: Department of Radiology, Pusan National University College of Medicine, 10 I-Ga, Ami-Dong, Seo-Ku, Pusan 502-739, South Korea.
authors.forename: Hak Jin
authors.initials: HJ
authors.lastname: Kim
authors.forename: Jong Hwa
authors.initials: JH
authors.lastname: Lee
authors.forename: Chang Hun
authors.initials: CH
authors.lastname: Lee
authors.forename: Suk Hong
authors.initials: SH
authors.lastname: Lee
authors.forename: Tae Yong
authors.initials: TY
authors.lastname: Moon
authors.forename: Byung Mann
authors.initials: BM
authors.lastname: Cho
authors.forename: Hae Kyu
authors.initials: HK
authors.lastname: Kim
authors.forename: Byung Rae
authors.initials: BR
authors.lastname: Park
authors.forename: Kee Hyun
authors.initials: KH
authors.lastname: Chang
mesh_terms: D000818:Animals; D001921:Brain / Q000473:pathology / Q000648:ultrastructure; D002415:Cats; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging; D004620:Embolism, Fat / Q000139:chemically induced / Q000175:diagnosis* / Q000473:pathology; D020766:Intracranial Embolism / Q000139:chemically induced / Q000175:diagnosis* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008854:Microscopy, Electron; D019301:Oleic Acid / Q000633:toxicity*; D014304:Triolein / Q000633:toxicity*
chemical_list: D003287:Contrast Media; D014304:Triolein; D019301:Oleic Acid