title: Suction/Inspiration against resistance or standardized Mueller maneuver : a new breathing technique to improve contrast density within the pulmonary artery: a pilot CT study.
abstract: OBJECTIVE
  Our aim was to prospectively investigate whether the recently introduced suction/inspiration against resistance breathing method leads to higher computed tomography (CT) contrast density in the pulmonary artery compared to standard breathing.
  
  
  METHODS
  The present study was approved by the Medical Ethics committee and all subjects gave written informed consent. Fifteen patients, each without suspicious lung emboli, were randomly assigned to four different groups with different breathing maneuvers (suction against resistance, Valsalva, inspiration, expiration) during routine CT. Contrast enhancement in the central and peripheral sections of the pulmonary artery were measured and compared with one another.
  
  
  RESULTS
  Peripheral enhancement during suction yielded increased mean densities of 138.14 Hounsfield units (HU) (p = 0.001), compared to Valsalva and a mean density of 67.97 HU superior to inspiration (p = 0.075). Finally, suction in comparison to expiration resulted in a mean increase of 30.51 HU (p = 0.42). Central parts of pulmonary arteries presented significantly increased enhancement values (95.74 HU) for suction versus the Valsalva technique (p = 0.020), while all other mean densities were in favour of suction (versus inspiration: p = 0.201; versus expiration: p = 0.790) without reaching significance.
  
  
  CONCLUSIONS
  Suction/Inspiration against resistance is a promising technique to improve contrast density within pulmonary vessels, especially in the peripheral parts, in comparison to other breathing maneuvers.
  
  
  CONCLUSIONS
  • Suction/Inspiration against resistance is promising to improve contrast density within the pulmonary artery. • Patients potentially suffering pulmonary embolism are able to follow suction/inspiration against resistance. • Contrast density after suction is superior in comparison to other breathing maneuvers.
authors.affiliation: Department of Radiology, Paracelsus Medical University Salzburg, Salzburg, Austria. agutzeit2000@gmail.com.|Institute of Radiology and Nuclear Medicine, Clinical Research Unit, Hirslanden Hospital St. Anna, St. Anna Strasse 12, 6006, Lucerne, Switzerland. agutzeit2000@gmail.com.|Department of Radiology, Kantonsspital Winterthur, Brauerstrasse 15, 8401, Winterthur, Switzerland. agutzeit2000@gmail.com.
authors.forename: Andreas
authors.initials: A
authors.lastname: Gutzeit
authors.affiliation: Institute of Radiology and Nuclear Medicine, Clinical Research Unit, Hirslanden Hospital St. Anna, St. Anna Strasse 12, 6006, Lucerne, Switzerland.
authors.forename: Johannes M
authors.initials: JM
authors.lastname: Froehlich
authors.affiliation: Department of Radiology and Nuclear Medicine, Cantonal Hospital St. Gallen, 9007, St. Gallen, Switzerland.
authors.forename: Stephan
authors.initials: S
authors.lastname: Wälti
authors.affiliation: Department of Radiology, Duke University Medical Center, Durham, NC, USA.
authors.forename: Justus E
authors.initials: JE
authors.lastname: Roos
authors.affiliation: Department of Radiology, Paracelsus Medical University Salzburg, Salzburg, Austria.
authors.forename: Matthias
authors.initials: M
authors.lastname: Meissnitzer
authors.affiliation: Department of Radiology, Paracelsus Medical University Salzburg, Salzburg, Austria.
authors.forename: Klaus
authors.initials: K
authors.lastname: Hergan
authors.affiliation: Institute of Radiology and Nuclear Medicine, Clinical Research Unit, Hirslanden Hospital St. Anna, St. Anna Strasse 12, 6006, Lucerne, Switzerland.
authors.forename: Constantin
authors.initials: C
authors.lastname: von Weymarn
authors.affiliation: Department of Neurology, Cantonal Hospital Winterthur, Brauerstrasse 15, 8401, Winterthur, Switzerland.
authors.forename: David
authors.initials: D
authors.lastname: Czell
authors.affiliation: Institute of Radiology and Nuclear Medicine, Clinical Research Unit, Hirslanden Hospital St. Anna, St. Anna Strasse 12, 6006, Lucerne, Switzerland.
authors.forename: Matthias
authors.initials: M
authors.lastname: Goyen
authors.affiliation: Department of Radiology, Paracelsus Medical University Salzburg, Salzburg, Austria.|Institute of Radiology and Nuclear Medicine, Clinical Research Unit, Hirslanden Hospital St. Anna, St. Anna Strasse 12, 6006, Lucerne, Switzerland.
authors.forename: Carolin
authors.initials: C
authors.lastname: Reischauer
mesh_terms: D061605:Administration, Intravenous; D000328:Adult; D000368:Aged; D003287:Contrast Media / Q000008:administration & dosage*; D045853:Exhalation / Q000502:physiology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D001239:Inhalation / Q000502:physiology; D007472:Iohexol / Q000008:administration & dosage / Q000031:analogs & derivatives; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D011651:Pulmonary Artery / Q000000981:diagnostic imaging*; D011856:Radiographic Image Enhancement / Q000379:methods*; D011873:Radiology Information Systems; D055425:Respiratory-Gated Imaging Techniques / Q000379:methods*; D013396:Suction; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014636:Valsalva Maneuver
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide
keywords: Breathing; Computed tomography angiography; Contrast density; Pulmonary embolism; Pulmonary vessel