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Suction against resistance: a new breathing technique to significantly improve the blood flow ratio of the superior and inferior vena cava

Gutzeit, Andreas ; Roos, Justus ; Hergan, Klaus ; von Weymarn, Constantin ; Wälti, Stephan ; Reischauer, Carolin ; Froehlich, Johannes

In: European Radiology, 2014, vol. 24, no. 12, p. 3034-3041

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    Title
    • Suction against resistance: a new breathing technique to significantly improve the blood flow ratio of the superior and inferior vena cava
    Author
    • Gutzeit, Andreas. Institute of Radiology and Nuclear Medicine, Clinical Research Unit of St. Anna Hospital Luzern, St. Anna Strasse 32, 6006, Luzern, Switzerland
    • Roos, Justus. Department of Radiology, Duke University, Durham, NC, USA
    • Hergan, Klaus. Department of Radiology, Paracelsus Medical University Salzburg, Salzburg, Austria
    • von Weymarn, Constantin. Institute of Radiology and Nuclear Medicine, Clinical Research Unit of St. Anna Hospital Luzern, St. Anna Strasse 32, 6006, Luzern, Switzerland
    • Wälti, Stephan. Department of Radiology, Cantonal Hospital, Winterthur, Switzerland
    • Reischauer, Carolin. Institute of Radiology and Nuclear Medicine, Clinical Research Unit of St. Anna Hospital Luzern, St. Anna Strasse 32, 6006, Luzern, Switzerland
    • Froehlich, Johannes. Institute of Radiology and Nuclear Medicine, Clinical Research Unit of St. Anna Hospital Luzern, St. Anna Strasse 32, 6006, Luzern, Switzerland
    Document Type
    • Postprint
    OAI-PMH Identifier
    • oai:doc.rero.ch:326262
    Summary
    Objectives: Optimal contrast within the pulmonary artery is achieved by the maximum amount of contrast-enhanced blood flowing through the superior vena cava (SVC), while minimum amounts of non-contrasted blood should originate from the inferior vena cava (IVC). This study aims to clarify whether "suction against resistance” might optimise this ratio. Methods: Phase-contrast pulse sequences on a 1.5T MRI magnet were used for flow quantification (mean flow (mL/s), stroke volume (Vol) in the SVC and IVC in volunteers. Different breathing manoeuvers were analysed repeatedly: free breathing; inspiration; expiration; suction against resistance, and Valsalva. To standardise breathing commands, volunteers performed suction and Valsalva manoeuvers with an MR-compatible manometer. Results: Suction against resistance was associated with a significant drop of the IVC/SVC flow quotient (1.63 [range 1.3-2.0] p < 0.05 at -10mmHg and 1.48 [1.1-1.9] p < 0.01 at -20mmHg) corresponding to increased blood flow from SVC and diminished flow originating from the IVC. The remaining breathing commands (free breathing 2.2; inspiration 2.4; expiration 2.4; Valsalva 10mmHg 2.3; Valsalva 20mmHg 2.6; and Valsalva 30mmHg 2.2) showed no differences (p > 0.05). Conclusions: Suction against resistance caused a significant drop in the IVC/SVC quotient. Theoretically, this breathing manoeuver might significantly improve the enhancement characteristics of CT angiography. Key Points: • Suction provokes reduction in blood flow in the inferior vena cava. • Ratio between the inferior and superior vena cava blood flow diminished during suction. • Manometer used during breathing standardises MR phase-contrast blood flow measurements.