title: MRI of the cat brain in the study of vascular permeability after intraarterial carotid injection of triolein.
abstract: BACKGROUND
  Triolein emulsion embolization into the carotid artery depicts reversible increased vascular permeability that can promote the effect of chemotherapy or can reduce the amount of chemotherapeutic drugs for equivalent effectiveness.
  
  
  OBJECTIVE
  To establish the minimum dosage of 0.5% triolein for studying vascular permeability changes in a triolein emulsion model.
  
  
  METHODS
  Sixty-six cats were divided into six groups based on the amount of emulsified triolein (0.5%) infused into the carotid artery: group 1 (n=12, 6 ml/kg), group 2 (n=12, 4.5 ml/kg), group 3 (n=12, 3 ml/kg), group 4 (n=10, 1.5 ml/kg), group 5 (n=10, 1 ml/kg), and group 6 (n=10, 3 ml/kg of saline (control group)). T1-weighted, T2-weighted, and post-contrast T1-weighted MRI was performed 2 h after the infusion of the triolein emulsion. Contrast enhancement ratios (CERs) were obtained with pre- and post-contrast T1-weighted images in the ipsilateral and contralateral hemispheres. Signal intensity ratios (SIRs) of the ipsilateral and contralateral hemispheres were evaluated on T2-weighted images. After removal of the brain tissues, edema ratios in the ipsilateral and contralateral hemispheres were obtained from wet versus dry brain weights. Data were statistically evaluated by analysis of variance, followed by the Tukey honestly significant difference test to compare the difference in the mean CER of the ipsilateral and contralateral hemispheres, mean SIR on T2-weighted image, and mean edema ratio between each group when overall significance was attained.
  
  
  RESULTS
  In the ipsilateral hemispheres, the difference in the CER between the control group and groups 1 (P=0.004), 2 (P=0.043), and 3 (P=0.008) were statistically significant. The difference in the CERs between the triolein emulsion groups was not statistically significant (P>0.05). The T2-weighted SIRs were significantly different between the control group and groups 1 (P=0.027) and 2 (P=0.004). However, the edema ratios of all doses in the triolein emulsion groups showed no significant differences compared with the control group.
  
  
  CONCLUSIONS
  The minimum dosage of 0.5% triolein emulsion to achieve increased vascular permeability in the hemisphere in cat brains appears to be 3 ml/kg. This minimum dosage of triolein emulsion can be useful for acquiring basic data in further studies of vascular permeability changes in a triolein emulsion model.
authors.affiliation: Department of Radiology, Dongrae Paik Hospital, Inje University College of Medicine, Postgraduate School, Pusan National University, Pusan, Korea.
authors.forename: Ji Hwa
authors.initials: JH
authors.lastname: Ryu
authors.forename: Yeon Joo
authors.initials: YJ
authors.lastname: Jeong
authors.forename: Hak Jin
authors.initials: HJ
authors.lastname: Kim
authors.forename: Dong Hyun
authors.initials: DH
authors.lastname: Kim
authors.forename: Dong Chan
authors.initials: DC
authors.lastname: Kim
authors.forename: Myong Joon
authors.initials: MJ
authors.lastname: Kim
authors.forename: Yong Woo
authors.initials: YW
authors.lastname: Kim
authors.forename: Seon Hee
authors.initials: SH
authors.lastname: Choi
authors.forename: Byung Mann
authors.initials: BM
authors.lastname: Cho
authors.forename: Tae Yong
authors.initials: TY
authors.lastname: Moon
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D016477:Artifacts; D002199:Capillary Permeability / Q000187:drug effects*; D002339:Carotid Arteries; D002415:Cats; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D003287:Contrast Media / Q000008:administration & dosage; D004655:Emulsions; D019786:Gadolinium DTPA / Q000008:administration & dosage; D007090:Image Interpretation, Computer-Assisted; D007269:Injections, Intra-Arterial; D008279:Magnetic Resonance Imaging / Q000379:methods*; D014304:Triolein / Q000008:administration & dosage* / Q000494:pharmacology*
chemical_list: D003287:Contrast Media; D004655:Emulsions; D014304:Triolein; D019786:Gadolinium DTPA