title: MRI of intracranial vertebral artery dissection: evaluation of intramural haematoma using a black blood, variable-flip-angle 3D turbo spin-echo sequence.
abstract: BACKGROUND
  We investigated the efficacy of three-dimensional black blood T1-weighted imaging (3D-BB-T1WI) using a variable refocusing flip angle turbo spin-echo sequence in the diagnosis of intracranial vertebral artery dissection (VAD).
  
  
  METHODS
  Sixteen consecutive patients diagnosed with intracranial VAD underwent magnetic resonance imaging that included 3D time-of-flight-MRA, axial spin-echo T1-weighted images (SE-T1WI) and oblique coronal 3D-BB-T1WI sequences. The visualization, morphology and extent of intramural haematomas were assessed and compared among the sequences. Results obtained by digital subtraction angiography (DSA), 3D-angiography and/or 3D-CT angiography (CTA) were used as standards of reference.
  
  
  RESULTS
  3D-BB-T1WI revealed intramural haematomas in all cases, whereas SE-T1WI and magnetic resonance angiography (MRA) failed to reveal a haematoma in one case and three cases, respectively. The mean visualization grading score for the intramural haematoma was the highest for 3D-BB-T1WI, and there was a statistically significant difference among the sequences (p < 0.001). At least a portion of the intramural haematoma was distinguishable from the lumen on 3D-BB-T1WI, whereas the haematomas were entirely indistinguishable from intraluminal signals on MRA in two cases (12.5%) and on SE-T1WI in one case (6.3%). 3D-BB-T1WI revealed the characteristic crescent shape of the intramural haematoma in 14 cases (87.5%), whereas SE-T1WI and MRA revealed a crescent shape in only 7 cases (43.8%) and 8 cases (50%), respectively. In a consensus reading, 3D-BB-T1WI was considered the most consistent sequence in representing the extent and morphology of the lesion in 14 cases (87.5%), compared to DSA and CTA.
  
  
  CONCLUSIONS
  3D-BB-T1WI is a promising method to evaluate intramural haematoma in patients with suspected intracranial VAD.
authors.affiliation: Department of Radiology, Faculty of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka-shi, Fukuoka 814-0180, Japan. k-takano@fukuoka-u.ac.jp
authors.forename: Koichi
authors.initials: K
authors.lastname: Takano
authors.forename: Shinnichi
authors.initials: S
authors.lastname: Yamashita
authors.forename: Koichiro
authors.initials: K
authors.lastname: Takemoto
authors.forename: Tooru
authors.initials: T
authors.lastname: Inoue
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Kuwabara
authors.forename: Kengo
authors.initials: K
authors.lastname: Yoshimitsu
mesh_terms: D000328:Adult; D000465:Algorithms; D002533:Cerebral Angiography / Q000379:methods*; D005260:Female; D006407:Hematoma, Epidural, Cranial / Q000209:etiology* / Q000473:pathology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020217:Vertebral Artery Dissection / Q000150:complications* / Q000473:pathology*