title: Advanced diffusion models in head and neck squamous cell carcinoma patients: Goodness of fit, relationships among diffusion parameters and comparison with dynamic contrast-enhanced perfusion.
abstract: We assessed advanced fitting models of diffusion weighted imaging (DWI) in head/neck squamous cell carcinoma (HNSCC) patients to determine the best goodness of fit and correlations among diffusion parameters. We compared these results with those of dynamic contrast-enhanced (DCE) perfusion parameters.
  
  
  
  We retrospectively evaluated 32 HNSCC patients (12 sinonasal, 20 pharynx/oral cavity). The DWI acquisition used single-shot spin-echo echo-planar imaging (EPI) with 12 b-values (0-2000). We calculated 14 DWI parameters using mono-exponential, bi-exponential, and tri-exponential models, stretched exponential model (SEM) and diffusion kurtosis imaging (DKI) models. We compared each model's goodness of fit using the residual sum of squares (RSS), Akaike Information Criterion (AIC) and Bayesian information criterion (BIC) value. We determined the correlation between each pair of DWI parameters and between each DWI parameter and DCE perfusion parameter.
  
  
  
  The tri-exponential fit's RSS, AIC and BIC values were significantly smaller than those for bi-exponential fit. The RSS, AIC and BIC values of the SEM fit and DKI fit were significantly smaller than mono-exponential model. Significant correlations were observed in 30 pairs (sinonasal cavity) and 31 (sinonasal cavity group) among 91 DWI parameter combinations. Significant correlations were also observed in nine pairs (both sinonasal cavity and pharynx/oral cavity group) among 64 DWI/DCE perfusion parameter pairs, in particular, high positive correlations between the tri-exponential model's intermediate diffusion fraction (f2) and the volume of the extracellular extravascular space per unit volume of tissue (ve) were observed in both patient groups.
  
  
  
  We identified several correlations between DWI parameters by advanced fitting models and correlations between DWI and DCE parameters. These will help determine HNSCC patients' detailed tissue structures.
authors.affiliation: Department of Diagnostic and Interventional Radiology, Hokkaido University Hospital, Sapporo, Japan. Electronic address: Noriyuki.Fujima@mb9.seikyou.ne.jp.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Fujima
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Sakashita
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Homma
authors.affiliation: Department of Diagnostic and Interventional Radiology, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Yukie
authors.initials: Y
authors.lastname: Shimizu
authors.affiliation: Department of Diagnostic and Interventional Radiology, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yoshida
authors.affiliation: Department of Diagnostic and Interventional Radiology, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Taisuke
authors.initials: T
authors.lastname: Harada
authors.affiliation: Department of Radiation Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan; The Global Station for Quantum Medical Science and Engineering, Global Institution for Collaborative Research and Education, Sapporo, Japan.
authors.forename: Khin Khin
authors.initials: KK
authors.lastname: Tha
authors.affiliation: Department of Diagnostic and Interventional Radiology, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Kohsuke
authors.initials: K
authors.lastname: Kudo
authors.affiliation: Department of Radiation Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan; The Global Station for Quantum Medical Science and Engineering, Global Institution for Collaborative Research and Education, Sapporo, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Shirato
mesh_terms: D000368:Aged; D001499:Bayes Theorem; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging*; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D017352:Echo-Planar Imaging / Q000379:methods; D005260:Female; D006257:Head / Q000000981:diagnostic imaging; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D009333:Neck / Q000000981:diagnostic imaging; D012189:Retrospective Studies; D000077195:Squamous Cell Carcinoma of Head and Neck
chemical_list: D003287:Contrast Media
keywords: Advanced fitting models; Diffusion weighted imaging; Dynamic contrast-enhanced perfusion; Head and neck squamous cell carcinoma