title: Focal liver lesions at 3.0 T: lesion detectability and image quality with T2-weighted imaging by using conventional and dual-source parallel radiofrequency transmission.
abstract: OBJECTIVE
  To prospectively compare T2-weighted single-shot turbo spin-echo (TSE) sequences performed with parallel and conventional radiofrequency (RF) transmission at 3.0 T for liver lesion detection, image quality, lesion conspicuity, and lesion contrast.
  
  
  METHODS
  After written informed consent and institutional review board approval, 52 consecutive patients (32 men, 20 women; mean age, 56.6 years ± 13.7 [standard deviation]) underwent routine magnetic resonance (MR) imaging with a clinical 3.0-T unit. Two independent readers reviewed images acquired with conventional and dual-source parallel RF transmission for detection of focal liver lesions, with separate reading of a third radiologist, including all available imaging findings, clinical history, and histopathologic findings, as reference. Image quality and lesion conspicuity were rated on five- and three-point evaluation scales, respectively. Contrast ratios between focal liver lesions and adjacent liver parenchyma were calculated. Significance was determined by using nonparametric Wilcoxon signed-rank and marginal homogeneity tests.
  
  
  RESULTS
  With the reference standard, 106 index lesions were identified in 22 patients. Detection rate significantly improved from 87% (92 of 106) to 97% (103 of 106) (reader 1) and from 85% (90 of 106) to 96% (102 of 106) (reader 2) with parallel RF transmission (reader 1, P = .0078; reader 2, P = .002). Quality of parallel RF transmission images was assigned scores significantly higher, compared with quality of conventional RF transmission images (mean for reader 1, 2.88 ± 0.73 vs 4.04 ± 0.44; mean for reader 2, 2.81 ± 0.72 vs 4.04 ± 0.39; P < .0001 for both). Lesion conspicuity scores were significantly higher on parallel RF transmission images, compared with conventional RF transmission images (mean for reader 1, 2.02 ± 0.64 vs 2.92 ± 0.27; mean for reader 2, 2.06 ± 0.67 vs 2.90 ± 0.30; P < .0001 for both). Contrast ratios were significantly higher with parallel RF transmission (P < .05).
  
  
  CONCLUSIONS
  Compared with conventional RF transmission, parallel RF transmission significantly improved liver lesion detection rate, image quality, lesion conspicuity, and lesion contrast.
  
  
  BACKGROUND
  http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11101429/-/DC1.
authors.affiliation: Department of Radiology, University of Bonn, Sigmund-Freud-Strasse 25, 53127 Bonn, Germany. Guido.Kukuk@ukb.uni-bonn.de
authors.forename: Guido M
authors.initials: GM
authors.lastname: Kukuk
authors.forename: Jürgen
authors.initials: J
authors.lastname: Gieseke
authors.forename: Sebastian
authors.initials: S
authors.lastname: Weber
authors.forename: Dariusch R
authors.initials: DR
authors.lastname: Hadizadeh
authors.forename: Michael
authors.initials: M
authors.lastname: Nelles
authors.forename: Frank
authors.initials: F
authors.lastname: Träber
authors.forename: Hans H
authors.initials: HH
authors.lastname: Schild
authors.forename: Winfried A
authors.initials: WA
authors.lastname: Willinek
mesh_terms: D000328:Adult; D000368:Aged; D016477:Artifacts; D003287:Contrast Media; D003911:Dextrans; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D021621:Imaging, Three-Dimensional; D008099:Liver; D008107:Liver Diseases / Q000175:diagnosis* / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058185:Magnetite Nanoparticles; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds; D011446:Prospective Studies; D011846:Radio Waves; D018709:Statistics, Nonparametric
chemical_list: D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; D009942:Organometallic Compounds; C090600:gadobutrol; C065507:ferumoxides