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Use of Angle‐Independent M‐Mode Sonography for Assessment of Diaphragm Displacement
Author(s) -
Orde Sam R.,
Boon Andrea J.,
Firth Daniel G.,
Villarraga Hector R.,
Sekiguchi Hiroshi
Publication year - 2016
Publication title -
journal of ultrasound in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 91
eISSN - 1550-9613
pISSN - 0278-4297
DOI - 10.7863/ultra.15.11100
Subject(s) - medicine , diaphragm (acoustics) , displacement (psychology) , ultrasonography , nuclear medicine , radiology , anatomy , acoustics , psychology , physics , psychotherapist , loudspeaker
Objectives Sonographic assessment of diaphragm displacement has conventionally been conducted with M‐mode sonography via an anterior subcostal approach. This method is subject to measurement errors when diaphragm displacement is not in line with the M‐mode plane. We aimed to compare measurements obtained by offline angle‐independent (anatomic) M‐mode sonography with conventional M‐mode sonography. Methods Fifty healthy adults were imaged with conventional and angle‐independent M‐mode sonography of the bilateral hemidiaphragms at 60% maximal inspiratory capacity using an inspiratory spirometer. Results Left hemidiaphragm displacement was successfully imaged by conventional M‐mode sonography in only 70% (n = 35), as lung expansion obscured imaging, whereas 92% (n = 46) were assessable by angle‐independent M‐mode sonography. All right hemidiaphragm displacement could be assessed. Conventional M‐mode results were higher than angle‐independent M‐mode results on the right (mean ± SD, 4.9 ± 1.4 versus 4.6 ± 1.2 cm, respectively; P = .003) and left (5.4 ± 1.3 versus 4.6 ± 1.0 cm; P < .001). Displacement values were different for right versus left hemidiaphragms on conventional M‐mode sonography (mean difference, 0.6 ± 0.2 cm; P = .005), with only mild agreement ( R 2 = 0.35; P < .001). There was no laterality seen in the diaphragm displacement on angle‐independent M‐mode sonography (mean difference, 0.1 ± 0.1 cm; P = .47), with good agreement ( R 2 = 0.76; P < .001). Conclusions Angle‐independent M‐mode sonography leads to better visualization and assessment of the left hemidiaphragm. It records lower displacement than conventional M‐mode sonography in the bilateral diaphragms, likely because of fewer orientation and translation errors. Future study is indicated to assess the clinical utility of angle‐independent M‐mode sonography in a population with diaphragm dysfunction.