Validity and reliability of rectus femoris ultrasound measurements: Comparison of curved-array and linear-array transducers

J Rehabil Res Dev. 2014;51(7):1155-64. doi: 10.1682/JRRD.2013.08.0187.

Abstract

Muscle-mass loss augers increased morbidity and mortality in critically ill patients. Muscle-mass loss can be assessed by wide linear-array ultrasound transducers connected to cumbersome, expensive console units. Whether cheaper, hand-carried units equipped with curved-array transducers can be used as alternatives is unknown. Accordingly, our primary aim was to investigate in 15 nondisabled subjects the validity of measurements of rectus femoris cross-sectional area by using a curved-array transducer against a linear-array transducer-the reference-standard technique. In these subjects, we also determined the reliability of measurements obtained by a novice operator versus measurements obtained by an experienced operator. Lastly, the relationship between quadriceps strength and rectus area recorded by two experienced operators with a curved-array transducer was assessed in 17 patients with chronic obstructive pulmonary disease (COPD). In nondisabled subjects, the rectus cross-sectional area measured with the curved-array transducer by the novice and experienced operators was valid (intraclass correlation coefficient [ICC]: 0.98, typical percentage error [%TE]: 3.7%) and reliable (ICC: 0.79, %TE: 9.7%). In the subjects with COPD, both reliability (ICC: 0.99) and repeatability (%TE: 7.6% and 9.8%) were high. Rectus area was related to quadriceps strength in COPD for both experienced operators (coefficient of determination: 0.67 and 0.70). In conclusion, measurements of rectus femoris cross-sectional area recorded with a curved-array transducer connected to a hand-carried unit are valid, reliable, and reproducible, leading us to contend that this technique is suitable for cross-sectional and longitudinal studies.

Keywords: COPD; critical illness myopathy; critical illness neuropathy; human muscle; intensive care unit; probe configuration; quadriceps femoris; reproducibility; sarcopenia; ultrasound imaging.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Validation Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Clinical Competence
  • Female
  • Healthy Volunteers
  • Humans
  • Male
  • Middle Aged
  • Muscle Strength
  • Observer Variation
  • Organ Size
  • Pulmonary Disease, Chronic Obstructive / pathology
  • Pulmonary Disease, Chronic Obstructive / physiopathology*
  • Quadriceps Muscle / anatomy & histology*
  • Quadriceps Muscle / diagnostic imaging*
  • Quadriceps Muscle / physiopathology
  • Reproducibility of Results
  • Transducers*
  • Ultrasonography / instrumentation
  • Young Adult