title: Prominent hypointense veins on susceptibility weighted image in the cat brain with acute infarction: DWI, SWI, and PWI.
abstract: BACKGROUND
  The multiple prominent hypointense veins on susceptibility-weighted imaging (SWI) have been found in the ischemic territory of patients with acute ischemic stroke. Venous side is the unknown area in the hemodynamics of brain infarction.
  
  
  OBJECTIVE
  To evaluate the venous aspect in acute brain infarction through an animal study.
  
  
  METHODS
  The acute infarction in cat brains was induced with a bolus infusion of 0.25 mL of triolein through one side of the common carotid artery. The magnetic resonance (MR) images, including diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC) map, SW, and perfusion-weighted (PWI) images, were obtained serially at 2 h (n = 17), 1 day (n = 11), and 4 days (n = 4) after triolein infusion. The obtained MR images were evaluated qualitatively and quantitatively. For qualitative assessment, the signal intensity of the serial MR images was evaluated. The presence or absence and the location with serial changes of infarction were identified on DWI and ADC map images. The presence or absence of prominent hypointense veins and the serial changes of cortical veins were also evaluated on SWI. Quantitative assessment was performed by comparing the relative cerebral blood volume (rCBV), cerebral blood flow (rCBF), and mean transit times (MTT) of the lesions with those of the contralateral normal side calculated on PWI. The serial changes of rCBV, rCBF, and MTT ratio were also evaluated.
  
  
  RESULTS
  Acute infarction in the first and second medial gyrus of lesion hemisphere was found by qualitative evaluation of DWI and ADC map images. On the serial evaluation of SWI, the cortical veins of cat brain with infarction were obscured at 2 h and then re-appeared at 1 day. The hemorrhage transformation and prominent hypointense veins were seen at 4 days on SWI. The quantitative evaluation revealed increased MTT ratios and decreased rCBV and rCBF ratios on PWIs in the acute infarction of cat brain.
  
  
  CONCLUSIONS
  The prominent hypointense veins on SWI were seen in the half of the acute infarction at 4 days. The prominent hypointense veins on SWI may have good agreement with the increased MTT ratio.
authors.affiliation: Department of Radiology, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea.
authors.forename: Yong-Woo
authors.initials: YW
authors.lastname: Kim
authors.affiliation: Department of Radiology, Pusan National University School of Medicine, Biomedical Research Institute, Pusan National University Hospital, Pusan, Republic of Korea hakjink@pusan.ac.kr.
authors.forename: Hak Jin
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Pusan National University Postgraduate School, Pusan, Republic of Korea.
authors.forename: Seon Hee
authors.initials: SH
authors.lastname: Choi
authors.affiliation: Seoul National University School of Veterinary Medicine, Seoul, Republic of Korea.
authors.forename: Dong Chan
authors.initials: DC
authors.lastname: Kim
mesh_terms: D000208:Acute Disease; D000818:Animals; D001921:Brain / Q000098:blood supply* / Q000473:pathology*; D020520:Brain Infarction / Q000139:chemically induced / Q000473:pathology*; D002415:Cats; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D004195:Disease Models, Animal; D017352:Echo-Planar Imaging / Q000379:methods; D019786:Gadolinium DTPA; D007089:Image Enhancement / Q000379:methods; D018810:Magnetic Resonance Angiography / Q000379:methods*; D014304:Triolein
chemical_list: D003287:Contrast Media; D014304:Triolein; D019786:Gadolinium DTPA
keywords: Brain infarction; MR; PWI; SWI; hemodynamics