title: Three-dimensional black-blood T2mapping with compressed sensing and data-driven parallel imaging in the carotid artery.
abstract: To develop a 3D black-blood T2mapping sequence with a combination of compressed sensing (CS) and parallel imaging (PI) for carotid wall imaging.
  
  
  
  A 3D black-blood fast-spin-echo (FSE) sequence for T2mapping with CS and PI was developed and validated. Phantom experiments were performed to assess T2accuracy using a Eurospin Test Object, with different combination of CS and PI acceleration factors. A 2D multi-echo FSE sequence was used as a reference to evaluate the accuracy. The concordance correlation coefficient and Bland-Altman statistics were calculated. Twelve volunteers were scanned twice to determine the repeatability of the sequence and the intraclass correlation coefficient (ICC) was reported. Wall-lumen sharpness was calculated for different CS and PI combinations. Six patients with carotid stenosis >50% were scanned with optimised sequence. The T2maps were compared with multi-contrast images.
  
  
  
  Phantom scans showed good correlation in T2measurement between current and reference sequence (r=0.991). No significant difference was found between different combination of CS and PI accelerations (p=0.999). Volunteer scans showed good repeatability of T2measurement (ICC: 0.93, 95% CI 0.84-0.97). The mean T2of the healthy wall was 48.0±9.5ms. Overall plaque T2values from patients were 54.9±12.2ms. Recent intraplaque haemorrhage and fibrous tissue have higher T2values than the mean plaque T2values (88.1±6.8ms and 62.7±9.3ms, respectively).
  
  
  
  This study demonstrates the feasibility of combining CS and PI for accelerating 3D T2mapping in the carotid artery, with accurate T2measurements and good repeatability.
authors.affiliation: Department of Radiology, University of Cambridge, United Kingdom. Electronic address: jy338@cam.ac.uk.
authors.forename: Jianmin
authors.initials: J
authors.lastname: Yuan
authors.affiliation: Department of Radiology, University of Cambridge, United Kingdom.
authors.forename: Ammara
authors.initials: A
authors.lastname: Usman
authors.affiliation: GE Healthcare, Amersham, United Kingdom.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Reid
authors.affiliation: GE Healthcare, Waukesha, WI, USA.
authors.forename: Kevin F
authors.initials: KF
authors.lastname: King
authors.affiliation: Department of Radiology, Cambridge University Hospitals NHS Foundation Trust, United Kingdom.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Patterson
authors.affiliation: Department of Radiology, University of Cambridge, United Kingdom.
authors.forename: Jonathan H
authors.initials: JH
authors.lastname: Gillard
authors.affiliation: Department of Radiology, University of Cambridge, United Kingdom; Department of Radiology, Cambridge University Hospitals NHS Foundation Trust, United Kingdom.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Graves
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002339:Carotid Arteries / Q000000981:diagnostic imaging*; D016893:Carotid Stenosis / Q000000981:diagnostic imaging*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D055815:Young Adult
keywords: Carotid imaging; Compressed sensing; Parallel imaging; T(2) mapping