title: Simultaneous multislice diffusion-weighted MRI of the liver: Analysis of different breathing schemes in comparison to standard sequences.
abstract: To systematically evaluate image characteristics of simultaneous-multislice (SMS)-accelerated diffusion-weighted imaging (DWI) of the liver using different breathing schemes in comparison to standard sequences.
  
  
  
  DWI of the liver was performed in 10 healthy volunteers and 12 patients at 1.5T using an SMS-accelerated echo planar imaging sequence performed with respiratory-triggering and free breathing (SMS-RT, SMS-FB). Standard DWI sequences served as reference (STD-RT, STD-FB). Reduction of scan time by SMS-acceleration was measured. Image characteristics of SMS-DWI and STD-DWI with both breathing schemes were analyzed quantitatively (apparent diffusion coefficient [ADC], signal-to-noise ratio [SNR]) and qualitatively (5-point Likert scale, 5 = excellent). Qualitative and quantitative parameters were compared using Friedman test and Dunn-Bonferroni post-hoc method with P-values < 0.05 considered statistically significant.
  
  
  
  SMS-DWI provided diagnostic image quality in volunteers and patients both with RT and FB with a reduction of scan time of 70% (0:56 vs. 3:20 min in FB). Overall image quality did not significantly differ between FB and RT acquisition in both STD and SMS sequences (median STD-RT 5.0, STD-FB 4.5, SMS-RT: 4.75; SMS-FB: 4.5; P = 0.294). SNR in the right hepatic lobe was comparable between the four tested sequences. ADC values were significantly lower in SMS-DWI compared to STD-DWI irrespective of the breathing scheme (1.2 ± 0.2 × 10(-3) mm(2) /s vs. 1.0 ± 0.2 × 10(-3) mm(2) /s; P < 0.001).
  
  
  
  SMS-acceleration provides considerable scan time reduction for hepatic DWI with equivalent image quality compared to the STD technique both using RT and FB. Discrepancies in ADC between STD-DWI and SMS-DWI need to be considered when transferring the SMS technique to clinical routine reading. J. MAGN. RESON. IMAGING 2016;44:865-879.
authors.affiliation: Diagnostic and Interventional Radiology, University Department of Radiology, University Hospital of Tuebingen, Tuebingen, Germany.
authors.forename: Jana
authors.initials: J
authors.lastname: Taron
authors.affiliation: Section on Experimental Radiology, University Department of Radiology, University Hospital of Tuebingen, Tuebingen, Germany.
authors.forename: Petros
authors.initials: P
authors.lastname: Martirosian
authors.affiliation: Department of Biomedical Magnetic Resonance, University Hospital of Tuebingen, Tuebingen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Erb
authors.affiliation: Institute of Signal Processing and System Theory, University of Stuttgart, Stuttgart, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kuestner
authors.affiliation: Diagnostic and Interventional Radiology, University Department of Radiology, University Hospital of Tuebingen, Tuebingen, Germany.
authors.forename: Nina F
authors.initials: NF
authors.lastname: Schwenzer
authors.affiliation: Diagnostic and Interventional Radiology, University Department of Radiology, University Hospital of Tuebingen, Tuebingen, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Schmidt
authors.affiliation: Diagnostic and Interventional Radiology, University Department of Radiology, University Hospital of Tuebingen, Tuebingen, Germany.
authors.forename: Valerie S
authors.initials: VS
authors.lastname: Honndorf
authors.affiliation: Diagnostic and Interventional Radiology, University Department of Radiology, University Hospital of Tuebingen, Tuebingen, Germany.
authors.forename: Jakob
authors.initials: J
authors.lastname: Weiβ
authors.affiliation: Diagnostic and Interventional Radiology, University Department of Radiology, University Hospital of Tuebingen, Tuebingen, Germany.
authors.forename: Mike
authors.initials: M
authors.lastname: Notohamiprodjo
authors.affiliation: Diagnostic and Interventional Radiology, University Department of Radiology, University Hospital of Tuebingen, Tuebingen, Germany.
authors.forename: Konstantin
authors.initials: K
authors.lastname: Nikolaou
authors.affiliation: Diagnostic and Interventional Radiology, University Department of Radiology, University Hospital of Tuebingen, Tuebingen, Germany. christina.schraml@med.uni-tuebingen.de.
authors.forename: Christina
authors.initials: C
authors.lastname: Schraml
mesh_terms: D000328:Adult; D000465:Algorithms; D016477:Artifacts; D062485:Breath Holding; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008099:Liver / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D008297:Male; D009038:Motion; D015203:Reproducibility of Results; D015656:Respiratory Mechanics; D055425:Respiratory-Gated Imaging Techniques / Q000379:methods*; D012680:Sensitivity and Specificity
keywords: diffusion-weighted imaging; free breathing; liver; respiratory triggering; simultaneous multislice