title: Intra-individual comparison of CAIPIRINHA VIBE technique with conventional VIBE sequences in contrast-enhanced MRI of focal liver lesions.
abstract: OBJECTIVE
  To evaluate the impact of controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA) volume interpolated breath-hold examination (VIBE) magnetic resonance imaging (MRI) technique on image quality, reader confidence, and inter-observer agreement for the assessment of focal liver lesions in comparison with the standard VIBE approach.
  
  
  METHODS
  In this IRB-approved intra-individual comparison study, abdominal arterial and portal-venous contrast-enhanced MRI studies were retrospectively analyzed in 38 patients with malignant liver lesions. Each patient underwent both CAIPIRINHA and conventional VIBE 3T MRI within 3 months, showing stable disease. Images were evaluated using 5-point rating scales by two blinded radiologists with more than 20 and 5 years of experience in MRI, respectively. Readers scored dignity of liver lesions and assessed which liver segments were affected by malignancy (ranging from 1=definitely benign/not affected to 5=definitely malignant/affected by malignancy). Readers also rated overall image quality, sharpness of intrahepatic veins, and diagnostic confidence (ranging from 1=poor to 5=excellent).
  
  
  RESULTS
  Reviewers achieved a higher inter-observer reliability using CAIPIRINHA when they reported which liver segments were affected by malignancy compared to traditional VIBE series (κ=0.62 and 0.54, respectively, p<0.05). Similarly, CAIPIRINHA showed a slightly higher inter-rater agreement for the dignity of focal liver lesions versus the standard VIBE images (κ=0.50 and 0.49, respectively, p<0.05). CAIPIRINHA series also scored higher in comparison to standard VIBE sequences (mean scores: image quality, 4.2 and 3.5; sharpness of intrahepatic vessels, 3.8 and 3.2, respectively, p<0.05) for both reviewers and allowed for higher subjective diagnostic confidence (ratings, 3.8 and 3.2, respectively, p<0.05).
  
  
  CONCLUSIONS
  Compared to the standard VIBE approach, CAIPIRINHA VIBE technique provides improved image quality and sharpness of intrahepatic veins, as well as higher diagnostic confidence. Additionally, this technique allows for higher inter-observer agreement when reporting focal liver lesions for both dignity and allocation.
authors.affiliation: University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt,Germany; Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC, USA. Electronic address: MoritzAlbrecht@gmx.net.
authors.forename: M H
authors.initials: MH
authors.lastname: Albrecht
authors.affiliation: University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt,Germany. Electronic address: boris.bodelle@kgu.de.
authors.forename: B
authors.initials: B
authors.lastname: Bodelle
authors.affiliation: Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC, USA. Electronic address: vargaasz@musc.edu.
authors.forename: A
authors.initials: A
authors.lastname: Varga-Szemes
authors.affiliation: University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt,Germany. Electronic address: patricia.dewes@kgu.de.
authors.forename: P
authors.initials: P
authors.lastname: Dewes
authors.affiliation: University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt,Germany. Electronic address: andreas.bucher@kgu.de.
authors.forename: A M
authors.initials: AM
authors.lastname: Bucher
authors.affiliation: Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC, USA. Electronic address: BallBr@musc.edu.
authors.forename: B D
authors.initials: BD
authors.lastname: Ball
authors.affiliation: Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC, USA. Electronic address: dececco@musc.edu.
authors.forename: C N
authors.initials: CN
authors.lastname: De Cecco
authors.affiliation: Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC, USA. Electronic address: schoepf@musc.edu.
authors.forename: U J
authors.initials: UJ
authors.lastname: Schoepf
authors.affiliation: Shihezi University, Department of Psychology, Beisi Road, Xinjiang, China. Electronic address: zhuxun@shzu.edu.cn.
authors.forename: X
authors.initials: X
authors.lastname: Zhu
authors.affiliation: University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt,Germany. Electronic address: Zangos@em.uni-frankfurt.de.
authors.forename: S
authors.initials: S
authors.lastname: Zangos
authors.affiliation: University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt,Germany. Electronic address: tatjanagruber2004@yahoo.de.
authors.forename: T
authors.initials: T
authors.lastname: Gruber-Rouh
authors.affiliation: University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt,Germany. Electronic address: dochwichmann@gmail.com.
authors.forename: J L
authors.initials: JL
authors.lastname: Wichmann
authors.affiliation: University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt,Germany. Electronic address: thomas.lehnert@klinikum-kassel.de.
authors.forename: T
authors.initials: T
authors.lastname: Lehnert
authors.affiliation: University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt,Germany. Electronic address: t.vogl@em.uni-frankfurt.de.
authors.forename: T J
authors.initials: TJ
authors.lastname: Vogl
mesh_terms: D000328:Adult; D000368:Aged; D062485:Breath Holding; D003287:Contrast Media; D005260:Female; D006499:Hepatic Artery / Q000473:pathology; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008107:Liver Diseases / Q000175:diagnosis*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011169:Portal Vein / Q000473:pathology; D015203:Reproducibility of Results
chemical_list: D003287:Contrast Media
keywords: CAIPIRINHA VIBE; Focal liver lesions; Image quality; Interobserver agreement; Liver MRI; Oncologic radiology