title: Salivary gland tumors: use of intravoxel incoherent motion MR imaging for assessment of diffusion and perfusion for the differentiation of benign from malignant tumors.
abstract: OBJECTIVE
  To prospectively evaluate the intravoxel incoherent motion (IVIM) parameters (microvascular volume fraction, f; pure diffusion coefficient, D; and perfusion-related incoherent microcirculation, D*) for differentiating between benign and malignant salivary gland tumors.
  
  
  METHODS
  All participants in this prospective institutional review board-approved study provided written informed consent. The perfusion and diffusion of 20 (65%) benign (12 pleomorphic adenomas and eight Warthin tumors) and 11 (35%) malignant salivary gland tumors were assessed on the basis of the IVIM theory. Diffusion-weighted magnetic resonance imaging was performed by using 11 b values (0-800 sec/mm(2)). The IVIM parameters of the salivary gland tumors were determined by a radiologist, and significant differences between the tumor types were assessed by using the Steel-Dwass test.
  
  
  RESULTS
  The f values of Warthin tumors (0.156 ± 0.039 [standard deviation]) were significantly larger than those of pleomorphic adenomas (0.066 ± 0.031) (P = .003). The D values of malignant tumors (0.96 × 10(-3) mm(2)/sec ± 0.22) were significantly different from those of benign tumors (pleomorphic adenomas, 1.38 × 10(-3) mm(2)/sec ± 0.30 [P = .002]; Warthin tumors, 0.61 × 10(-3) mm(2)/sec ± 0.11 [P = .005]). The D* values of malignant tumors (21.99 × 10(-3) mm(2)/sec ± 19.01) were significantly smaller than those of Warthin tumors (42.64 × 10(-3) mm(2)/sec ± 20.17) (P = .022). The combination of D and D* criteria provided the best diagnostic accuracy (100%) for differentiation among the three tumor types.
  
  
  CONCLUSIONS
  IVIM imaging may be helpful for differentiation between benign and malignant salivary gland tumors.
authors.affiliation: Department of Radiology and Cancer Biology, Nagasaki University School of Dentistry, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan.
authors.forename: Misa
authors.initials: M
authors.lastname: Sumi
authors.forename: Marc
authors.initials: M
authors.lastname: Van Cauteren
authors.forename: Tadateru
authors.initials: T
authors.lastname: Sumi
authors.forename: Makoto
authors.initials: M
authors.lastname: Obara
authors.forename: Yoko
authors.initials: Y
authors.lastname: Ichikawa
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakamura
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009038:Motion; D011446:Prospective Studies; D012468:Salivary Gland Neoplasms / Q000175:diagnosis* / Q000473:pathology; D018709:Statistics, Nonparametric
chemical_list: D003287:Contrast Media