Related Experiment Video
Updated: Jan 25, 2026

Induction of Acute Skeletal Muscle Regeneration by Cardiotoxin Injection
Published on: January 1, 2017
Echogenicity Is Related to Skeletal Muscle Strength in Patients With Acute Respiratory Failure
Michael J Berry1, D Clark Files, Claudia L Campos
1Department of Health and Exercise Science, Wake Forest University, Winston-Salem, North Carolina (Dr Berry and Ms Skaggs); Department of Internal Medicine, Wake Forest University School of Medicine, Wake Forest University, Winston-Salem, North Carolina (Drs Files, Campos, and Bakhru); and Department of Internal Medicine, University of Kentucky, Lexington, Kentucky (Dr Morris).
Purpose:
Patients with acute respiratory failure (ARF) show changes in skeletal muscle structure and strength. The purpose of this study was to examine the relationship between muscle thickness, echogenicity, and strength in patients with ARF.
Methods:
Thirteen (6 females, 7 males) patients with ARF participated in the study. Knee extensor strength was measured via a handheld dynamometer and quadriceps images were obtained via ultrasonography at hospital discharge. The ultrasonograms were used to obtain muscle thickness and both mean ± SD echogenicity of the rectus femoris, vastus lateralis, and vastus medialis. Partial correlations, controlling for age, body mass index, and fluid intake were used to describe the relationships among knee extensor strength and echogenicity and muscle thickness.
Results:
Knee extensor strength and vastus lateralis SD echogenicity were significantly correlated when controlling for age, body mass index, and fluid intake (r = 0.69, P = .029). Knee extensor strength and vastus lateralis echogenicity were 19.1 ± 8.0 kg and 19.8 ± 5.4 units, respectively. No other correlations between strength and ultrasound measures were found to be significant.
Conclusion:
These results show skeletal muscle echogenicity to be significantly correlated with skeletal muscle strength in patients with ARF. As such, it may be useful in identifying muscle weakness in these patients when they are unable or unwilling to perform voluntary strength testing.
Related Concept Videos
Acute Respiratory Failure-I
Definition: It is defined by specific criteria based on blood gas measurements. Hypoxemia happens when the partial pressure of oxygen (PaO2) falls below 60 mmHg. At the same time,...
Acute Respiratory Failure-II
The underlying physiological abnormalities that contribute to hypoxemic respiratory failure include:
Acute Respiratory Failure-V
Ensure that patients are monitored continuously for their response to therapy, including changes in...
Acute Respiratory Failure-III
Acute Respiratory Failure-IV
Classification of Skeletal Muscle Fibers
Slow-Twitch Muscle Fibers
Slow oxidative, muscle fibers appear red due to large numbers of capillaries and high levels of...

