Interobserver reliability of quantitative muscle sonographic analysis in the critically ill population

Aarti Sarwal, Selina M. Parry, Michael J. Berry, Fang Chi Hsu, Marc T. Lewis, Nicholas W. Justus, Peter E. Morris, Linda Denehy, Sue Berney, Sanjay Dhar, Michael S. Cartwright

Research output: Contribution to journalArticlepeer-review

97 Scopus citations


Objectives - There is growing interest in the use of quantitative high-resolution neuro muscular sonography to evaluate skeletal muscles in patients with critical illness. There is currently considerable methodological variability in the measurement technique of quantitative muscle analysis. The reliability of muscle parameters using different measurement techniques and assessor expertise levels has not been examined in patients with critical illness. The primary objective of this study was to determine the interobserver reliability of quantitative sonographic measurement analyses (thickness and echogenicity) between assessors of different expertise levels and using different techniques for selecting the region of interest. Methods - We conducted a cross-sectional observational study in neurocritical care and mixed surgical-medical intensive care units from 2 tertiary referral hospitals. Results - Twenty diaphragm and 20 quadriceps images were evaluated. Images were obtained by using standardized imaging acquisition techniques. Quantitative sonographic measurements included muscle thickness and echogenicity analysis (either by the trace or square technique). All images were analyzed twice independently by 4 assessors of differing expertise levels. Excellent interobserver reliability was obtained for all measurement techniques regardless of expertise level (intraclass correlation coefficient, >0.75 for all comparisons). There was less variability between assessors for echogenicity values when the square technique was used for the quadriceps muscle and the trace technique for the diaphragm. Conclusions - Excellent interobserver reliability exists regardless of expertise level for quantitative analysis of muscle parameters on sonography in the critically ill population. On the basis of these findings, it is recommended that echogenicity analysis be performed using the square technique for the quadriceps and the trace technique for the diaphragm.

Original languageEnglish
Pages (from-to)1191-1200
Number of pages10
JournalJournal of Ultrasound in Medicine
Issue number7
StatePublished - Jul 1 2015

Bibliographical note

Publisher Copyright:
©2015 by the American Institute of Ultrasound in Medicine.


  • Critical care weakness
  • Grayscale analysis
  • Muscle
  • Musculoskeletal ultrasound
  • Sonography

ASJC Scopus subject areas

  • Radiological and Ultrasound Technology
  • Radiology Nuclear Medicine and imaging


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