title: Ultrasound point shear wave elastography assessment of liver and spleen stiffness: effect of training on repeatability of measurements.
abstract: OBJECTIVE
  To evaluate reproducibility of measurements of spleen stiffness (SS) and liver stiffness (LS) at several sites by using point shear wave elastography (pSWE) and to investigate any training effect.
  
  
  METHODS
  Healthy volunteers were consecutively enrolled. Measurements of SS and LS were performed by an expert (observer 1) and a novice (observer 2) at three different sites of liver and spleen. To assess the effect of training the study was conducted in two periods (period 1 and period 2). Concordance correlation coefficient was used to assess intra-observer and inter-observer reproducibility.
  
  
  RESULTS
  A total of 92 subjects (67 men and 25 women) were enrolled in the study. Both intra-observer and inter-observer agreement were higher for the liver than for the spleen. Overall, the highest intra-observer and inter-observer agreement were obtained for the assessment of LS through intercostal space, and for measurements at this site there was a significantly better performance of observer 2 after the training period. For both observers, training improved the repeatability of SS measurements at all sites. A good intra-observer agreement was obtained only for measurements at the spleen lower pole.
  
  
  CONCLUSIONS
  The results of this study show that a learning curve in pSWE acquisition should be taken into account both for SS and LS measurements.
  
  
  CONCLUSIONS
  Reproducibility of SS measurements depends on the expertise of the operator. To achieve good reproducibility between measurements a training period is required. A learning curve in pSWE acquisition should be taken into account. SS measurements are less reproducible than LS measurements.
authors.affiliation: Ultrasound Unit - Infectious Diseases Department, Fondazione IRCCS Policlinico San Matteo, University of Pavia, Via Taramelli 5, 27100, Pavia, Italy, giovanna.ferraioli@unipv.it.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Ferraioli
authors.forename: Carmine
authors.initials: C
authors.lastname: Tinelli
authors.forename: Raffaella
authors.initials: R
authors.lastname: Lissandrin
authors.forename: Mabel
authors.initials: M
authors.lastname: Zicchetti
authors.forename: Stefano
authors.initials: S
authors.lastname: Bernuzzi
authors.forename: Laura
authors.initials: L
authors.lastname: Salvaneschi
authors.forename: Carlo
authors.initials: C
authors.lastname: Filice
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D054459:Elasticity Imaging Techniques / Q000379:methods* / Q000592:standards* / Q000706:statistics & numerical data; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D015203:Reproducibility of Results; D013154:Spleen / Q000000981:diagnostic imaging*; D055815:Young Adult