title: [Evolution rules and clinical value of apparent diffusion coefficient in cerebral infarction].
abstract: OBJECTIVE
  To determine the rules that apparent diffusion coefficient (ADC) changes with time and space in cerebral infarction, and to provide the evidence in defining the stage, guiding treatment or judging the prognosis in infarction.
  
  
  METHODS
  Eighty-eight work-ups in 69 patients with cerebral infarction (8 hyperacute, 35 acute, 20 subacute, and 25 chronic infarctions) were imaged with both conventional MRI and diffusion weighted imaging. The average ADC, the average relative ADC (rADC), and the ADC or rADC from the center to the periphery of the lesion were calculated.
  
  
  RESULTS
  The average ADC and the average rADC of hyperacute and acute infarction lesion depressed obviously. The average ADC and the average rADC of subacute infarction lesion were significantly higher than those of hyperacute and acute infarction lesion (P < 0.05), and some approached the values of uninjured side which appeared "pseudonormal values" at 10 to 14 days. The average ADC and the average rADC in chronic infarction lesion were the highest (P < 0.05). The longer the prognosis, the higher the average ADC and the average rADC of infarction lesion. The ADC and the rADC in 7 hyperacute and 26 acute lesions had gradient signs that these lesions increased from the center to the periphery. The ADC and the rADC in 15 subacute lesions had adverse gradient signs that these lesions decreased from the center to the periphery.
  
  
  CONCLUSIONS
  The ADC and the rADC of infarction lesions have evolution rules with time and space corresponding to the pathophysiological foundation. The evolution rules with time and those in space can be helpful to decide the clinical stage and pathophysiological phase of infarction, and to provide the evidence in guiding the treatment or judging the prognosis in infarction.
authors.affiliation: Department of Radiology, Xiangya Hospital, Central South University, Changsha, China. yindan3418@126.com
authors.forename: Dan
authors.initials: D
authors.lastname: Yin
authors.forename: Li-meng
authors.initials: LM
authors.lastname: Deng
authors.forename: Xiao-yi
authors.initials: XY
authors.lastname: Wang
mesh_terms: D000368:Aged; D001921:Brain / Q000473:pathology; D002544:Cerebral Infarction / Q000175:diagnosis* / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D013997:Time Factors