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Real-time Breath Analysis by Using Secondary Nanoelectrospray Ionization Coupled to High Resolution Mass Spectrometry
Published on: March 9, 2018
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Pulmonary blood mass dynamics on 4DCT during tidal breathing
Nicholas Myziuk1,2, Thomas Guerrero1,3,4, Gukan Sakthivel3
1Department of Radiation Oncology, Beaumont Health, Royal Oak, MI, United States of America.
Physics in Medicine and Biology
|January 18, 2019
Summary
Pulmonary blood mass varies with breathing in all patients, with greater mass during inhalation. This respiratory-induced variation in 4D CT scans reflects changes in pulmonary perfusion.
Area of Science:
- Medical Imaging
- Pulmonary Physiology
- Radiotherapy Physics
Background:
- Apparent lung mass on 4D CT scans varies with breathing phases.
- This variation is hypothesized to reflect physiological changes in pulmonary perfusion during tidal breathing.
Purpose of the Study:
- To characterize and quantify respiratory-induced variation in pulmonary blood mass (ΔPBM).
- To investigate the relationship between ΔPBM and tidal volume.
- To evaluate the spatial distribution of ΔPBM variation.
Main Methods:
- Computed ΔPBM from helical 4D CT scans of 89 patients undergoing stereotactic body radiotherapy.
- Converted Hounsfield Units to density and mass per voxel using a calibration curve.
- Analyzed lung parenchyma volume within each breathing phase.
Main Results:
- A difference in lung mass with breathing was found in all patients.
- ΔPBM increased during inhalation and decreased during exhalation.
- A significant positive correlation was observed between ΔPBM and tidal volume.
- Spatial distribution of ΔPBM variation agreed with previous findings.
Conclusions:
- Respiratory-induced variation in pulmonary mass is apparent on 4D CT scans.
- These variations reflect changes in pulmonary perfusion.
- 4D CT-derived ΔPBM can offer insights into pulmonary circulation and aid in diagnosing lung diseases.
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