title: Comparison between the M and XL probes for liver fibrosis assessment by transient elastography.
abstract: OBJECTIVE
  Liver stiffness measurement (LSM) using Transient Elastography (TE) for liver fibrosis assessment is difficult to be performed in obese and overweight patients by standard M probe, thus the XL probe was developed. The aim of our paper was to assess the usefulness of the XL probe in daily clinical practice.
  
  
  METHODS
  Our study included 216 patients (mean BMI 30.1+/-4.1 kg/m2) with chronic hepatopathies, in which paired measurements were made using the M (3.5MHz) and XL (2.5 MHz) probes in the same session. In each patient 10 valid LSM were acquired with each probe, a median was calculated, expressed in kiloPascals (kPa). Unreliable TE measurements were considered: fewer than 10 valid shots; with a success rate (SR) <60% and/or interquartile range interval (IQR) ≥30%.
  
  
  RESULTS
  In 127 patients reliable LSM could not be obtained by standard M probe, 10 of them normal weight, 25 of them overweight, and 92 obese. By XL probe reliable measurements were obtained in 80/127(63%) of these patients: 8/10 (80%) of the normal weights, 17/25 (68%) of the overweight and 55/92 (59.8%) of the obese. In 98 patients with reliable M probe measurements, XL probe LSMs were also performed. XL LS values strongly and significantly correlated with those obtained by M probe (Spearman r=0.789, p<0.0001), but were significantly lower [median 6.4 kPa (range 3.1 - 53.8) vs 7.7 kPa (range 3.7-69.1), Wilcoxon paired t test p<0.001)].
  
  
  CONCLUSIONS
  By using the XL probe, reliable LSM by TE can be obtained in more than 60% of patients with unreliable measurements by M probe. LSM by XL probe are significantly correlated, but lower, than those obtained by M probe.
authors.affiliation: Department of Gastroenterology and Hepatology, "Victor Babes" University and Medicine Timisoara, Romania. roxanasirli@gmail.com.
authors.forename: Roxana
authors.initials: R
authors.lastname: Şirli
authors.affiliation: Department of Gastroenterology and Hepatology, "Victor Babes" University and Medicine Timisoara, Romania.
authors.forename: Ioan
authors.initials: I
authors.lastname: Sporea
authors.affiliation: Department of Gastroenterology and Hepatology, "Victor Babes" University and Medicine Timisoara, Romania.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Deleanu
authors.affiliation: Department of Gastroenterology and Hepatology, "Victor Babes" University and Medicine Timisoara, Romania.
authors.forename: Laura
authors.initials: L
authors.lastname: Culcea
authors.affiliation: Department of Gastroenterology and Hepatology, "Victor Babes" University and Medicine Timisoara, Romania.
authors.forename: Milana
authors.initials: M
authors.lastname: Szilaski
authors.affiliation: Department of Gastroenterology and Hepatology, "Victor Babes" University and Medicine Timisoara, Romania.
authors.forename: Alina
authors.initials: A
authors.lastname: Popescu
authors.affiliation: Department of Gastroenterology and Hepatology, "Victor Babes" University and Medicine Timisoara, Romania.
authors.forename: Mirela
authors.initials: M
authors.lastname: Dănilă
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D054459:Elasticity Imaging Techniques / Q000295:instrumentation*; D004867:Equipment Design; D005260:Female; D019694:Hepatitis B, Chronic / Q000000981:diagnostic imaging; D019698:Hepatitis C, Chronic / Q000000981:diagnostic imaging; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease / Q000000981:diagnostic imaging; D009765:Obesity / Q000000981:diagnostic imaging; D050177:Overweight / Q000000981:diagnostic imaging; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014159:Transducers