title: Relationship between apparent diffusion coefficient and tumour cellularity in lung cancer.
abstract: OBJECTIVE
  To prospectively investigate the relationship between the apparent diffusion coefficient (ADC) and cellularity in lung cancer.
  
  
  METHODS
  Sixty patients histopathologically confirmed with lung cancer (41 men, 19 women) underwent diffusion-weighted magnetic resonance imaging of the chest (with b values of 50 and 1000 s/mm2). The median mean ADC (ADC mean) value and median minimum ADC (ADC min) value within each primary tumour were calculated and compared with the median nucleo-cytoplasmic ratio (NCR), which was selected to represent the cellularity. The correlation between the NCR and ADC mean/ADC min was calculated with SPSS 18.0 software.
  
  
  RESULTS
  The mean ADC mean values, ADC min values and median NCR were (1.07 ± 0.12) × 10(-3) mm2/s, (0.86 ± 0.14) × 10(-3) mm2/s, and (14.9 ± 2.6) %, respectively, in adenocarcinoma; (0.88 ± 0.10) × 10(-3) mm2/s, (0.73 ± 0.12) × 10(-3)) mm2/s, and (20.6 ± 4.4) %, respectively, in squamous cell carcinoma; and (0.89 ± 0.13) × 10(-3) mm2/s, (0.67 ± 0.13) × 10(-3) mm2/s, and (18.3 ± 3.5) %, respectively in small cell lung cancer. The NCR of squamous cell carcinoma and small cell lung cancer is greater than that of adenocarcinoma (P < 0.01 and P = 0.002, respectively). There was an inverse relationship between ADC mean/NCR and ADC min/NCR (r = -0.60, P = 0.001 and r = -0.47, P < 0.001, respectively).
  
  
  CONCLUSIONS
  There is a significant inverse relationship between tumour cellularity and ADC in lung cancer. However, tumour cellularity most likely is not the sole determinant of the ADC.
authors.affiliation: Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China; Department of Radiology, PLA 101st Hospital, Wuxi Jiangsu, China.
authors.forename: Lihua
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Jiuquan
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Respiratory Medicine, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Yongfeng
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Respiratory Medicine, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Wenwei
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Respiratory Medicine, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Xiangdong
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Pathology, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Xiaochu
authors.initials: X
authors.lastname: Yan
authors.affiliation: Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000473:pathology; D002467:Cell Nucleus / Q000473:pathology; D003593:Cytoplasm / Q000473:pathology; D004058:Diffusion; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology*; D008297:Male; D011446:Prospective Studies; D055752:Small Cell Lung Carcinoma / Q000473:pathology; D012984:Software; D013909:Thorax / Q000473:pathology