title: Correlation of apparent diffusion coefficient with Ki-67 in the diagnosis of gliomas.
abstract: OBJECTIVE
  To study the correlation between apparent diffusion coefficient (ADC) and Ki-67, a marker of tumor activity, in the diagnosis of gliomas.
  
  
  METHODS
  Conventional magnetic resonance imaging (MRI), enhanced scanning, and diffusion-weighted imaging were performed in 76 patients with pathologically confirmed gliomas. The ADC values were measured at tumor parenchyma and the corresponding contralateral normal brain. The relatively ADC (rADC) values of the tumor parenchyma were calculated. The correlation of the ADC values with tumor grades was analyzed. The expression of Ki-67 was detected by immunohistochemical staining. The correlation between ADC value and Ki-67 in the diagnosis of gliomas was analyzed.
  
  
  RESULTS
  The ADC values and rADC values of high-grade gliomas were significantly lower than those of low-grade gliomas. The ADC values of tumor parenchyma were inversely associated with the degree of malignancy of the gliomas (r=-0.898, r=-0.868; P<0.01). The expression of Ki-67 was significantly higher in high-grade gliomas than that in low-grade gliomas. The Ki-67 labeling index in grade 3 and 4 gliomas were (29.48 ± 19.78)% and (31.21 ± 17.50)%, respectively. Both of them were significantly higher than Ki-67 labeling index in low-grade (grade 1 and 2) gliomas [(2.33 ± 2.20)%] (P<0.01). Nevertheless, the Ki-67 labeling index showed no significant difference between grade 3 and 4 gliomas (P>0.05). The expression of Ki-67 was negatively correlated with the ADC values and rADC values in tumor parenchyma (r=-0.627, r=-0.607; P<0.01).
  
  
  CONCLUSIONS
  The ADC and rADC values of tumor parenchyma can indirectly reflect the proliferation and malignancy of gliomas and therefore can be useful for the grading of glioma.
authors.affiliation: Department of Radiology, The First Affiliated Hospital of Jilin University, Changchun 130021, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Yin
authors.forename: Dan
authors.initials: D
authors.lastname: Tong
authors.forename: Xiao-yun
authors.initials: XY
authors.lastname: Liu
authors.forename: Ting-ting
authors.initials: TT
authors.lastname: Yuan
authors.forename: Yu-zhu
authors.initials: YZ
authors.lastname: Yan
authors.forename: Yue
authors.initials: Y
authors.lastname: Ma
authors.forename: Rui
authors.initials: R
authors.lastname: Zhao
mesh_terms: D000293:Adolescent; D000328:Adult; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D005910:Glioma / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D019394:Ki-67 Antigen