title: Efficacy of the radial acquisition regime (RADAR) for acquiring head and neck MR images.
abstract: OBJECTIVE
  To investigate the efficacy of the radial acquisition regime (RADAR) for acquiring head and neck MR images.
  
  
  METHODS
  15 healthy volunteers underwent imaging with 4 sequences [fast spin echo T2weighted imaging (FSE-T2WI), RADAR T2weighted imaging (RADAR-T2WI), single-shot echo planar imaging diffusion-weighted imaging (SS-EPI-DWI) and RADAR diffusion-weighted imaging (RADAR-DWI)]. Both standard images and images during periodic mouth motion were acquired. Two radiologists scored the overall image artefacts and detectability of several anatomical structures without knowledge of sequence type. For each sequence, image distortion was quantitatively compared by the anteroposterior to right-left ratio of several anatomical structures. The mean scores of artefacts and distortion of several anatomical structures were compared using the multiple comparison test. The detectabilities were compared using the Wilcoxon signed-rank test.
  
  
  RESULTS
  Regardless of mouth motion, RADAR-T2WI was significantly superior to FSE-T2WI in artefacts and oral-area detectability (p < 0.01), and RADAR-DWI was significantly superior to SS-EPI-DWI in terms of artefacts (p < 0.01). In terms of image distortion, RADAR-DWI was significantly superior to SS-EPI-DWI (p < 0.01).
  
  
  CONCLUSIONS
  RADAR-T2WI could replace FSE-T2WI as a conventional T2WI protocol for the head and neck. For the RADAR-DWI sequence, validation studies are needed. Advances in knowledge: RADAR-T2WI was superior to FSE-T2WI with regard to artefacts and detectability, and RADAR-DWI was superior in terms of artefacts compared with SS-EPI-DWI.
authors.affiliation: 1 Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Kojima
authors.affiliation: 1 Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Hidetake
authors.initials: H
authors.lastname: Yabuuchi
authors.affiliation: 2 Hitachi Medical Corporation, Tokyo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Narita
authors.affiliation: 1 Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Kumazawa
authors.affiliation: 3 Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Yuzo
authors.initials: Y
authors.lastname: Yamasaki
authors.affiliation: 1 Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Yano
authors.affiliation: 1 Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Sakai
authors.affiliation: 4 Department of Radiology, Kimura Hospital, Fukuoka, Japan.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Kurihara
authors.affiliation: 4 Department of Radiology, Kimura Hospital, Fukuoka, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Hisada
authors.affiliation: 4 Department of Radiology, Kimura Hospital, Fukuoka, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Masaki
authors.affiliation: 5 Department of Surgery, Kimura Hospital, Fukuoka, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kimura
mesh_terms: D016477:Artifacts; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D017352:Echo-Planar Imaging; D005260:Female; D006257:Head / Q000000981:diagnostic imaging*; D064368:Healthy Volunteers; D006801:Humans; D007089:Image Enhancement; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D009068:Movement; D009333:Neck / Q000000981:diagnostic imaging*; D055815:Young Adult