title: One-lung flooding reduces the ipsilateral diaphragm motion during mechanical ventilation.
abstract: BACKGROUND
  Diaphragm motion during spontaneous or mechanical respiration hinders image-guided percutaneous interventions of tumours in lung and upper abdomen. Motion-tracking methods can be applied but increase procedure complexity and procedure time. One-lung flooding (OLF) generates a suitable acoustic pathway to lung tumours and likely suppress diaphragm motion. The aim of this study was to quantify the effect of OLF on ipsilateral diaphragm motion during contralateral one-lung ventilation.
  
  
  METHODS
  To measure the diaphragm motion, M-mode ultrasonography of the right hemidiaphragm was performed during spontaneous breathing and mechanical ventilation, as well as after right-side lung flooding, in three pigs. Diaphragm motion was analysed using magnetic resonance images during left-side lung flooding and mechanical ventilation, in four pigs.
  
  
  RESULTS
  Double-lung ventilation increased the diaphragm movement in comparison with spontaneous breathing (17.8 ± 4.4 vs. 12.2 ± 3.4 mm, p = 0.014). Diaphragm movement on the flooded side during contralateral one-lung ventilation was significantly reduced compared to that during double-lung ventilation (3.9 ± 1.0 vs. 17.8 ± 4.4 mm, p = 0.041). By analysing the magnetic resonance images, the hemidiaphragm on the flooded side showed an average displacement of 4.2 mm, a maximum displacement of 15 mm close to the ventilated lung and no displacement at the lateral side.
  
  
  CONCLUSIONS
  OLF leads to a drastic reduction of diaphragm motion on the ipsilateral side which implies that targeting and motion compensation algorithms for interventions like high-intensity focused ultrasound ablation of intrapulmonary and hepatic lesions might not be required.
authors.affiliation: Department of Thoracic and Vascular Surgery, SRH Wald-Klinikum Gera, Teaching Hospital of Friedrich-Schiller University of Jena, Strasse des Friedens 122, 07548, Gera, Germany. thomas.lesser@wkg.srh.de.
authors.forename: Thomas Günther
authors.initials: TG
authors.lastname: Lesser
authors.affiliation: Institute of Animal Experimentation and Animal Welfare, Jena University Hospital, Friedrich-Schiller University, Jena, Germany. Harald.Schubert@med.uni-jena.de.
authors.forename: Harald
authors.initials: H
authors.lastname: Schubert
authors.affiliation: Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital, Friedrich-Schiller University, Jena, Germany. Daniel.Guellmar@med.uni-jena.de.
authors.forename: Daniel
authors.initials: D
authors.lastname: Güllmar
authors.affiliation: Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital, Friedrich-Schiller University, Jena, Germany. Juergen.Reichenbach@med.uni-jena.de.
authors.forename: Jürgen R
authors.initials: JR
authors.lastname: Reichenbach
authors.affiliation: Department of Thoracic and Vascular Surgery, SRH Wald-Klinikum Gera, Teaching Hospital of Friedrich-Schiller University of Jena, Strasse des Friedens 122, 07548, Gera, Germany. frank.wolfram@wkg.srh.de.
authors.forename: Frank
authors.initials: F
authors.lastname: Wolfram
mesh_terms: D000818:Animals; D003964:Diaphragm / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000662:veterinary; D009068:Movement; D011654:Pulmonary Edema / Q000503:physiopathology*; D011859:Radiography; D012119:Respiration; D012121:Respiration, Artificial / Q000379:methods*; D013552:Swine; D013553:Swine Diseases / Q000503:physiopathology*; D014463:Ultrasonography / Q000379:methods / Q000662:veterinary