title: Role of periodically rotated overlapping parallel lines with enhanced reconstruction diffusion-weighted imaging in correcting distortion and evaluating head and neck masses using 3 T MRI.
abstract: OBJECTIVE
  To investigate the role of periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) diffusion-weighted imaging (DWI) in correcting distortion and evaluating head and neck masses.
  
  
  METHODS
  Both PROPELLER and echo planar diffusion weighted imaging (EP-DWI) with different b values were performed using 3 T MRI in 50 patients with solid masses of the head and neck. Distortion severity of 50 masses with both DWI techniques and different b values was qualitatively scored and compared. The apparent diffusion coefficient (ADC) values of the 45 masses, in which the distortion scores with both DWI techniques were ≥2, were measured and calculated. The mean ADC value of each DWI sequence between benign and malignant masses was compared.
  
  
  RESULTS
  The mean distortion scores of PROPELLER DWIs were significantly higher than EP-DWIs (3.87 versus 1.96, and 3.88 versus 2.00, with b values of 1000 and 500 s/mm(2), respectively, p < 0.001), indicating distortion of the mass on PROPELLER DWIs was much less than that on EP-DWIs. With either PROPELLER or EP-DWI, the mean ADC value of 24 malignant tumours was significantly lower than that of 21 benign masses (p < 0.001).
  
  
  CONCLUSIONS
  Severe distortion of head and neck masses can be reduced significantly using PROPELLER DWI. Moreover, PROPELLER DWI plays an important role in differentiating malignancies from benign masses.
authors.affiliation: Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
authors.forename: X
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing, China; Beijing Key Laboratory of Nasal Diseases, Beijing, China. Electronic address: cjr.xianjunfang@vip.163.com.
authors.forename: J
authors.initials: J
authors.lastname: Xian
authors.affiliation: Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
authors.forename: X
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
authors.forename: J
authors.initials: J
authors.lastname: Guo
authors.affiliation: Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
authors.forename: J
authors.initials: J
authors.lastname: Li
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002681:China / Q000453:epidemiology; D038524:Diffusion Magnetic Resonance Imaging; D055088:Early Detection of Cancer; D017352:Echo-Planar Imaging; D005260:Female; D006258:Head and Neck Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D011446:Prospective Studies; D015203:Reproducibility of Results