title: Non-small cell lung cancer: Whole-lesion histogram analysis of the apparent diffusion coefficient for assessment of tumor grade, lymphovascular invasion and pleural invasion.
abstract: OBJECTIVE
  Investigating the diagnostic accuracy of histogram analyses of apparent diffusion coefficient (ADC) values for determining non-small cell lung cancer (NSCLC) tumor grades, lymphovascular invasion, and pleural invasion.
  
  
  METHODS
  We studied 60 surgically diagnosed NSCLC patients. Diffusion-weighted imaging (DWI) was performed in the axial plane using a navigator-triggered single-shot, echo-planar imaging sequence with prospective acquisition correction. The ADC maps were generated, and we placed a volume-of-interest on the tumor to construct the whole-lesion histogram. Using the histogram, we calculated the mean, 5th, 10th, 25th, 50th, 75th, 90th, and 95th percentiles of ADC, skewness, and kurtosis. Histogram parameters were correlated with tumor grade, lymphovascular invasion, and pleural invasion. We performed a receiver operating characteristics (ROC) analysis to assess the diagnostic performance of histogram parameters for distinguishing different pathologic features.
  
  
  RESULTS
  The ADC mean, 10th, 25th, 50th, 75th, 90th, and 95th percentiles showed significant differences among the tumor grades. The ADC mean, 25th, 50th, 75th, 90th, and 95th percentiles were significant histogram parameters between high- and low-grade tumors. The ROC analysis between high- and low-grade tumors showed that the 95th percentile ADC achieved the highest area under curve (AUC) at 0.74. Lymphovascular invasion was associated with the ADC mean, 50th, 75th, 90th, and 95th percentiles, skewness, and kurtosis. Kurtosis achieved the highest AUC at 0.809. Pleural invasion was only associated with skewness, with the AUC of 0.648.
  
  
  CONCLUSIONS
  ADC histogram analyses on the basis of the entire tumor volume are able to stratify NSCLCs' tumor grade, lymphovascular invasion and pleural invasion.
authors.affiliation: Department of Radiology, Kanazawa Medical University, Uchinada, Ishikawa, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Tsuchiya
authors.affiliation: Department of Radiology, Kanazawa Medical University, Uchinada, Ishikawa, Japan.
authors.forename: Mariko
authors.initials: M
authors.lastname: Doai
authors.affiliation: Department of Thoracic Surgery, Kanazawa Medical University, Uchinada, Ishikawa, Japan.
authors.forename: Katsuo
authors.initials: K
authors.lastname: Usuda
authors.affiliation: Department of Thoracic Surgery, Kanazawa Medical University, Uchinada, Ishikawa, Japan.
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Uramoto
authors.affiliation: Department of Radiology, Kanazawa Medical University, Uchinada, Ishikawa, Japan.
authors.forename: Hisao
authors.identifier: http://orcid.org/0000-0003-0930-4732
authors.initials: H
authors.lastname: Tonami
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology*; D000368:Aged; D000369:Aged, 80 and over; D018287:Carcinoma, Large Cell / Q000473:pathology*; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology*; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007089:Image Enhancement; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008175:Lung Neoplasms / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009361:Neoplasm Invasiveness; D010997:Pleural Neoplasms / Q000473:pathology*; D011379:Prognosis; D012372:ROC Curve; D012189:Retrospective Studies; D047368:Tumor Burden
chemical_list: D003287:Contrast Media