title: Usefulness of R2* maps generated by iterative decomposition of water and fat with echo asymmetry and least-squares estimation quantitation sequence for cerebral artery dissection.
abstract: BACKGROUND
  Acute intramural hematoma resulting from cerebral artery dissection is usually visualized as a region of intermediate signal intensity on T1-weighted images (WI). This often causes problems with distinguishing acute atheromatous lesions from surrounding parenchyma and dissection. The present study aimed to determine whether or not R2* maps generated by the iterative decomposition of water and fat with echo asymmetry and least-squares estimation quantitation sequence (IDEAL IQ) can distinguish cerebral artery dissection more effectively than three-dimensional variable refocusing flip angle TSE T1WI (T1-CUBE) and T2*WI.
  
  
  METHODS
  We reviewed data from nine patients with arterial dissection who were assessed by MR images including R2* maps, T2*WI, T1-CUBE, and 3D time-of-flight (TOF)-MRA. We visually assessed intramural hematomas in each patient as positive (clearly visible susceptibility effect reflecting intramural hematoma as hyperintensity on R2* map and hypointensity on T2*WI), negative (absent intramural hematoma), equivocal (difficult to distinguish between intramural hematoma and other paramagnetic substances such as veins, vessel wall calcification, or hemorrhage) and not evaluable (difficult to determine intramural hematoma due to susceptibility artifacts arising from skull base).
  
  
  RESULTS
  Eight of nine patients were assessed during the acute phase. Lesions in all eight patients were positive for intramural hematoma corresponding to dissection sites on R2* maps, while two lesions were positive on T2*WI and three lesions showed high-intensity on T1-CUBE reflected intramural hematoma during the acute phase.
  
  
  CONCLUSIONS
  R2* maps generated using IDEAL IQ can detect acute intramural hematoma associated with cerebral artery dissection more effectively than T2*WI and earlier than T1-CUBE.
authors.affiliation: Division of Radiology, Department of Pathophysiological, and Therapeutic Science, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago, 683-8504, Japan. katoayumy@gmail.com.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Kato
authors.affiliation: Division of Radiology, Department of Pathophysiological, and Therapeutic Science, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago, 683-8504, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Shinohara
authors.affiliation: Division of Clinical Radiology, Tottori University Hospital, Yonago, Japan.
authors.forename: Eijiro
authors.initials: E
authors.lastname: Yamashita
authors.affiliation: Division of Radiology, Department of Pathophysiological, and Therapeutic Science, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago, 683-8504, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Fujii
authors.affiliation: Division of Radiology, Department of Pathophysiological, and Therapeutic Science, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago, 683-8504, Japan.
authors.forename: Fuminori
authors.initials: F
authors.lastname: Miyoshi
authors.affiliation: Division of Radiology, Department of Pathophysiological, and Therapeutic Science, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago, 683-8504, Japan.
authors.forename: Keita
authors.initials: K
authors.lastname: Kuya
authors.affiliation: Division of Radiology, Department of Pathophysiological, and Therapeutic Science, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago, 683-8504, Japan.
authors.forename: Toshihide
authors.initials: T
authors.lastname: Ogawa
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002526:Cerebellar Diseases / Q000175:diagnosis*; D002543:Cerebral Hemorrhage / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005260:Female; D006406:Hematoma / Q000175:diagnosis*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed; D020217:Vertebral Artery Dissection / Q000175:diagnosis*
keywords: Cerebral artery dissection; IDEAL IQ; R2* map; T2*WI