title: The Value of MRI and Clinical Features in Differentiating Between Cellular and Fibrous Solitary Fibrous Tumors.
abstract: OBJECTIVE
  The purpose of this study is to evaluate the usefulness of MRI in differentiating between fibrous and cellular solitary fibrous tumors (SFTs).
  
  
  METHODS
  This retrospective study included 17 patients with histopathologically confirmed SFTs, including 10 patients with fibrous SFTs and seven patients with cellular SFTs. We evaluated the differences between fibrous and cellular SFTs with regard to clinical data and MRI findings, such as tumor margin definition, signal intensity, heterogeneity on T1- and T2-weighted images, presence of capsules, intratumoral cystic changes, flow signal void, perilesional edema, enhancement pattern on dynamic contrast-enhanced MRI (DCE-MRI), and mean apparent diffusion coefficient (ADC) values.
  
  
  RESULTS
  Statistically significant differences in fibrous and cellular SFTs were noted with respect to signal intensity on T2-weighted images (p = 0.044, by Fisher exact test) and enhancement patterns on DCE-MRI (p = 0.005, by Fisher exact test). Specifically, on T2-weighted images, five of the fibrous SFTs had high signal intensity, and the other five had signal isointensity, whereas all seven cellular SFTs had high signal intensity. On DCE-MRI, fibrous SFTs tended to show a gradual increase in enhancement, whereas cellular SFTs showed a rapid initial enhancement pattern. The mean (± SD) ADC value for cellular SFTs was 1.39 ± 0.35 × 10-3mm2/s, whereas that for fibrous SFTs was 1.37 ± 0.48 × 10-3mm2/s, with no statistically significant difference noted between the two (p = 0.755, by Fisher exact test).
  
  
  CONCLUSIONS
  Fibrous SFTs have nonspecific findings with regard to signal intensity on T2-weighted MR images and enhancement patterns on DCE-MRI, whereas cellular SFTs show high signal intensity on T2-weighted images and rapid initial enhancement on DCE-MRI.
authors.affiliation: 1 Department of Radiology, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka, 830-0011, Japan.
authors.forename: Shuji
authors.initials: S
authors.lastname: Nagata
authors.affiliation: 2 Department of Radiology, Saiseikai Futsukaichi Hospital, Chikushino, Fukuoka, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nishimura
authors.affiliation: 3 Department of Radiology, Mayo Clinic, Rochester, MN.
authors.forename: Kimberly K
authors.initials: KK
authors.lastname: Amrami
authors.affiliation: 4 Department of Pathology, Kurume University School of Medicine, Kurume, Fukuoka, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Akiba
authors.affiliation: 1 Department of Radiology, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka, 830-0011, Japan.
authors.forename: Tatsuyuki
authors.initials: T
authors.lastname: Tonan
authors.affiliation: 1 Department of Radiology, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka, 830-0011, Japan.
authors.forename: Kiminori
authors.initials: K
authors.lastname: Fujimoto
authors.affiliation: 1 Department of Radiology, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Fukuoka, 830-0011, Japan.
authors.forename: Toshi
authors.initials: T
authors.lastname: Abe
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D054364:Solitary Fibrous Tumors / Q000145:classification / Q000000981:diagnostic imaging* / Q000473:pathology*; D055815:Young Adult
keywords: DWI; T2-weighted MRI; apparent diffusion coefficient; dynamic contrast-enhanced MRI; solitary fibrous tumor