title: Real-time measurement of alveolar size and population using phase contrast x-ray imaging.
abstract: Herein a propagation-based phase contrast x-ray imaging technique for measuring particle size and number is presented. This is achieved with an algorithm that utilizes the Fourier space signature of the speckle pattern associated with the images of particles. We validate this algorithm using soda-lime glass particles, demonstrating its effectiveness on random and non-randomly packed particles. This technique is then applied to characterise lung alveoli, which are difficult to measure dynamically in vivo with current imaging modalities due to inadequate temporal resolution and/or depth of penetration and field-of-view. We obtain an important result in that our algorithm is able to measure changes in alveolar size on the micron scale during ventilation and shows the presence of alveolar recruitment/de-recruitment in newborn rabbit kittens. This technique will be useful for ventilation management and lung diagnostic procedures.
authors.affiliation: School of Physics, Monash University, Vic 3800, Australia.
authors.forename: Andrew F T
authors.initials: AF
authors.lastname: Leong
authors.affiliation: School of Physics, Monash University, Vic 3800, Australia.
authors.forename: Genevieve A
authors.initials: GA
authors.lastname: Buckley
authors.affiliation: School of Physics, Monash University, Vic 3800, Australia.
authors.forename: David M
authors.initials: DM
authors.lastname: Paganin
authors.affiliation: The Ritchie Centre MIMR-PHI Institute of Medical Research and the Department of Obstetrics and Gynaecology, Monash University, Vic 3168, Australia.
authors.forename: Stuart B
authors.initials: SB
authors.lastname: Hooper
authors.affiliation: The Ritchie Centre MIMR-PHI Institute of Medical Research and the Department of Obstetrics and Gynaecology, Monash University, Vic 3168, Australia.
authors.forename: Megan J
authors.initials: MJ
authors.lastname: Wallace
authors.affiliation: School of Physics, Monash University, Vic 3800, Australia.
authors.forename: Marcus J
authors.initials: MJ
authors.lastname: Kitchen
keywords: (100.5070) Phase retrieval; (110.6150) Speckle imaging; (170.3660) Light propagation in tissues; (170.3880) Medical and biological imaging; (290.5850) Scattering, particles; (340.7440) X-ray imaging