Hyperpolarized Xe magnetic resonance spectroscopy in a rat model of bronchopulmonary dysplasia.

Premature infants often require mechanical ventilation and oxygen therapy, which can result in bronchopulmonary dysplasia (BPD), characterized by developmental arrest and impaired lung function. Conventional clinical methods for assessing the prenatal lung are not adequate for the detection and assessment of long-term health risks in infants with BPD, highlighting the need for a noninvasive tool for the characterization of lung microstructure and function. Theoretical diffusion models, like the model of xenon exchange (MOXE), interrogate alveolar gas exchange by predicting the uptake of inert hyperpolarized (HP) Xe gas measured with HP Xe magnetic resonance spectroscopy (MRS).

Effect of inhaled oxygen concentration on Xe chemical shift of red blood cells in rat lungs.

Purpose: To investigate the dependence of dissolved Xe chemical shift on the fraction of inhaled oxygen, F O , in the lungs of healthy rats.

Methods: The chemical shifts of Xe dissolved in red blood cells, δ , and blood plasma and/or tissue, δ , were measured using MRS in 12 Sprague Dawley rats mechanically ventilated at F O values of 0.14, 0.

Application of a stretched-exponential model for morphometric analysis of accelerated diffusion-weighted 129Xe MRI of the rat lung.

Objective: Diffusion-weighted, hyperpolarized Xe MRI is useful for the characterization of microstructural changes in the lung. A stretched exponential model was proposed for morphometric extraction of the mean chord length (L) from diffusion-weighted data. The stretched exponential model enables accelerated mapping of L in a single-breathhold using compressed sensing.

Flexible polarimetric probe for 3 × 3 Mueller matrix measurements of biological tissue.

Polarimetry is a noninvasive method that uses polarised light to assess biophysical characteristics of tissues. A series of incident polarisation states illuminates a biological sample, and analysis of sample-altered polarisation states enables polarimetric tissue assessment. The resultant information can, for example, help quantitatively differentiate healthy from pathologic tissue.

Texture analysis of optical coherence tomography speckle for characterizing biological tissues in vivo.

We demonstrate a method for differentiating tissue disease states using the intrinsic texture properties of speckle in optical coherence tomography (OCT) images of normal and tumor tissues obtained in vivo. This approach fits a gamma distribution function to the nonlog-compressed OCT image intensities, thus allowing differentiation of normal and tumor tissues in an ME-180 human cervical cancer mouse xenograft model. Quantitative speckle intensity distribution analysis thus shows promise for identifying tissue pathologies, with potential for early cancer detection in vivo.