Abstract
Background
Neuromuscular ultrasound can be used to assess the diaphragm. Before it can be used clinically, the reference ranges of diaphragm thickness and contractility must be determined. Methods: We measured the thickness of the diaphragm and the diaphragmatic thickening fraction (DTF) in 80 healthy volunteers with ultrasound and collected their demographic information to determine if age, sex, and body mass index (BMI) influence these measures. Results: The thickness of the diaphragm at resting end expiration was 0.193 ± 0.044 cm on the right side and 0.187 ± 0.039 cm on the left. The DTF was 104.8 ± 50.6% on the right side and 114.9 ± 49.2% on the left. Sex, weight, height, and BMI significantly affected the thickness of the diaphragm, but had little effect on the DTF. Conclusions: Normal reference values for the diaphragm should be helpful when evaluating the diaphragm. The DTF appears more useful than resting diaphragm thickness because it is affected less by individual variation.
Citations
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- Diaphragmatic ultrasound: approach, emerging evidence, and future perspectives in non-ICU patients
Sigmund J. Kharasch, Andrea Loewen, Kevin J. Solverson, Tara Lohmann, Irene W. Y. Ma
Internal and Emergency Medicine.2025; 20(3): 643. CrossRef - Ultrasound Assessment of Diaphragmatic Function: Methodology, Normative Values
P. G. Evgrafov, L. T. Khamidova, S. S. Petrikov
Russian Sklifosovsky Journal "Emergency Medical Ca.2025; 14(1): 37. CrossRef - Ultrasound examination in assessing the functional state of the diaphragm in patients with respiratory failure requiring respiratory support
P. G. Evgrafov, L. T. Hamidova, S. S. Petrikov, V. V. Kulabukhov
Messenger of ANESTHESIOLOGY AND RESUSCITATION.2024; 21(3): 76. CrossRef - Diaphragm Assessment by Multimodal Ultrasound Imaging in Healthy Subjects
Tianjie Zhang, Yan Liu, Dongwei Xu, Rui Dong, Ye Song
International Journal of General Medicine.2024; Volume 17: 4015. CrossRef - Efficacy of ultrasonographic diaphragmatic parameters in distinguishing diaphragmatic dysfunction in cats
Phasamon Saisawart, Somchin Sutthigran, Tanya Kasemsuwan, Run Sakulsirajit, Sukullaya Ritthikulprasert, Kittipong Tachampa, Chutimon Thanaboonnipat, Nan Choisunirachon
Journal of Feline Medicine and Surgery.2024;[Epub] CrossRef - EXpert consensus On Diaphragm UltraSonography in the critically ill (EXODUS): a Delphi consensus statement on the measurement of diaphragm ultrasound-derived parameters in a critical care setting
Mark E. Haaksma, Jasper M. Smit, Alain Boussuges, Alexandre Demoule, Martin Dres, Giovanni Ferrari, Paolo Formenti, Ewan C. Goligher, Leo Heunks, Endry H. T. Lim, Lidwine B. Mokkink, Eleni Soilemezi, Zhonghua Shi, Michele Umbrello, Luigi Vetrugno, Emmanue
Critical Care.2022;[Epub] CrossRef - Ultrasound Imaging of the Diaphragm
Jung Im Seok
Journal of the Korean Neurological Association.2021; 39(4): 270. CrossRef - Holistic Ultrasound to Predict Extubation Failure in Clinical Practice
Mark E Haaksma, Jasper M Smit, Micah LA Heldeweg, Jip S Nooitgedacht, Leila N Atmowihardjo, Annemijn H Jonkman, Heder J de Vries, Endry HT Lim, Thei Steenvoorden, Erik Lust, Armand RJ Girbes, Leo MA Heunks, Pieter R Tuinman
Respiratory Care.2021; 66(6): 994. CrossRef - Neuromuscular Ultrasound in Amyotrophic Lateral Sclerosis
Jung Im Seok
Journal of Neurosonology and Neuroimaging.2019; 11(1): 73. CrossRef - Sonographic evaluation of the diaphragm in patients with unilateral diaphragmatic paralysis
Jung Im Seok, Kyung Chan Kim, Hye Joo Rha, Sung Rok Lee
Annals of Clinical Neurophysiology.2018; 20(2): 93. CrossRef - Is ultrasonography a main armament or just a supplement for evaluating patients with neuromuscular disorder?
Ye-Ji Kwon, Byung-Jo Kim
Annals of Clinical Neurophysiology.2017; 19(2): 77. CrossRef