title: Diffusion-weighted magnetic resonance imaging in preoperative assessment of non-small cell lung cancer.
abstract: BACKGROUND
  Diffusion-weighted magnetic resonance imaging (DWI) frequently shows heterogeneity of signal intensity (SI) in non-small cell lung cancer (NSCLC). The purpose of our study was to examine the association of SI and DWI patterns with histology, tumor invasiveness, lymph node metastasis, and (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) uptake in NSCLC.
  
  
  METHODS
  One hundred forty-five patients with NSCLC underwent preoperative DWI and FDG-PET. DWI patterns were visually classified as homogenous (HOM) (n = 81) or heterogeneous (HET) (n = 64). The former was further classified as faint (faint-HOM) (n = 27) or dark (dark-HOM) (n = 54) according to a cutoff value of SI. Associations of SI and DWI patterns with tumor histology, lymphatic or vascular invasion, pleural invasion, lymph node metastasis, and FDG uptake were evaluated.
  
  
  RESULTS
  All faint-HOM tumors were well-differentiated adenocarcinoma, whereas dark-HOM and HET tumors were less-differentiated adenocarcinoma or non adenocarcinoma. Although the dark areas in HET tumors showed a dense aggregation of tumor cells, their faint areas showed abundant fibrovascular stroma or necrosis, or a well-differentiated part of adenocarcinoma. Tumor size and the frequencies of lymphatic or vascular invasion, pleural invasion, and nodal metastasis were highest in HET tumors, followed by dark-HOM and faint-HOM (P = .1-P < .001) tumors. Sixty-five tumors having at least 1 of the invasions or metastasis showed significantly higher SI than the 81 tumors without (P < .001). HET tumors had the highest FDG uptake, followed by dark-HOM and faint-HOM tumors; differences between the groups were significant (P < .01 to P < .001).
  
  
  CONCLUSIONS
  The SI and heterogeneity of DWI reflect the histologic heterogeneity, tumor aggressiveness, and FDG-PET uptake in NSCLC.
authors: Department of Thoracic Surgery, Kameda Medical Center, Chiba, Japan. Electronic address: hnomori@qk9.so-net.ne.jp.
authors: Hiroaki
authors: H
authors: Nomori
authors: Department of Thoracic Surgery, Kameda Medical Center, Chiba, Japan.
authors: Yue
authors: Y
authors: Cong
authors: Department of Thoracic Surgery, Kameda Medical Center, Chiba, Japan.
authors: Masaru
authors: M
authors: Abe
authors: Department of Thoracic Surgery, Kameda Medical Center, Chiba, Japan.
authors: Hiroshi
authors: H
authors: Sugimura
authors: Department of Diagnostic Radiology, Kameda Medical Center, Chiba, Japan.
authors: Yoshiaki
authors: Y
authors: Kato
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D000077192:Adenocarcinoma of Lung; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D002454:Cell Differentiation; D038524:Diffusion Magnetic Resonance Imaging; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D009361:Neoplasm Invasiveness; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: Diffusion-weighted imaging; fluorodeoxyglucose; heterogeneity; lung cancer; magnetic resonance imaging; positron emission tomography