Distribution of lung tissue hysteresis during free breathing.

Purpose: To characterize and quantify free breathing lung tissue motion distributions.

Methods: Forty seven patient data sets were acquired using a 4DCT protocol consisting of 25 ciné scans at abutting couch positions on a 16-slice scanner. The tidal volume of each scan was measured by simultaneously acquiring spirometry and an abdominal pneumatic bellows.

On a PCA-based lung motion model.

Respiration-induced organ motion is one of the major uncertainties in lung cancer radiotherapy and is crucial to be able to accurately model the lung motion. Most work so far has focused on the study of the motion of a single point (usually the tumor center of mass), and much less work has been done to model the motion of the entire lung. Inspired by the work of Zhang et al (2007 Med.

Investigation of a breathing surrogate prediction algorithm for prospective pulmonary gating.

Purpose: A major challenge of four dimensional computed tomography (4DCT) in treatment planning and delivery has been the lack of respiration amplitude and phase reproducibility during image acquisition. The implementation of a prospective gating algorithm would ensure that images would be acquired only during user-specified breathing phases. This study describes the development and testing of an autoregressive moving average (ARMA) model for human respiratory phase prediction under quiet respiration conditions.

Aqueous liquid scintillation counting with fluor-containing nanosuspensions.

A microemulsion comprised of water, Brij 78, pentanol and styrene into which PPO and bis-MSB had been dissolved was prepared. Polymerization of the styrene resulted in a suspension of fluor-containing polystyrene nanoparticles (<100 nm). After a concentration step, the aqueous nanosuspension was able to detect (14)C with counting efficiencies over 50% of those of a commercially available scintillation cocktail.