Morphological changes in the respiratory system: an MRI investigation of differences between the supine and left lateral decubitus positions

ABSTRACT

Preoperative serial imaging of the torso is typically carried out in the supine position (e.g. magnetic resonance imaging [MRI], CT), however, intraoperative patient positioning is often lateral, and for some procedures may involve deflation and/or ventilation of the lungs. This study examined the differences in lung anatomy between the supine and lateral decubitus positions. MRI data for 10 healthy female adult volunteers lying in supine and left lateral decubitus positions were analysed. 2D measurements in coronal, transverse and sagittal planes were used to calculate the cross-sectional area, height and width of the lungs and the shape of the diaphragm. 3D surface reconstructions of the lungs and bronchi were created to determine the volume change between positions. The volume of the right lung was found to increase due to the caudal shift of the insertion points of the right hemidiaphragm (mean volume increase of 25% ± 11, p ≪ 0.05). There was minimal change in the left lung parameters with no significant change in left lung volume between positions (mean volume change = 0% ± 44%, p > 0.05). This study presents new information characterising anatomical changes in the respiratory system when a patient is positioned in the lateral decubitus compared to supine position.

KEYWORDS:

• Surgery
• respiratory system
• lung volume
• lung morphology
• measurement
• image analysis
• 3D reconstruction

Acknowledgments

The authors would like to gratefully acknowledge the support of Sealy Australia, who provided the MRI clinical imaging that formed the basis for this research study.

Similarly, the authors would like to acknowledge the support of the Mater Public Radiology Department in Brisbane, Australia and in particular Mrs Sue Mills and Ms Margaux Page, for their continued support with MRI scanning.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

J. Paige Little

A/Prof Little is a  mechanical engineer and leads Spine Research in the Biomechanics and Spine Research Group at QUT.

Erin Chapman

Ms Chapman is a graduate Medical Engineer.

Adam Parr

Dr Parr is a consultant spinal orthopaedic surgeon at the Queensland Children’s Hospital.

Gregory Moloney

Dr Moloney is a senior anaesthetics consultant at the Queensland Children’s Hospital.

Simon Bowler

Dr Bowler is a respiratory and sleep physician at the Mater Private Hospital.

Robert D. Labrom

Dr Labrom is a senior spinal consultant at the Queensland Children’s Hospital and Clinical Co-Director of the Biomechanics and Spine Research Group at QUT.

Geoffrey N. Askin

Dr Askin is a senior spinal consultant at the Queensland Children’s Hospital and Clinical Director of the Biomechanics and Spine Research Group at QUT.