Artikel des Tages: Visualization of Inert Gas Wash-Out During High- Frequency Oscillatory Ventilation Using Fluorine-19 MRI

Der heutige Artikel beschäftigt sich mit der Lungenbildgebung unter Anwendung von ¹⁹F als NMR-Sonde. Die Autoren sind Mitarbeiter des Uniklinikums Mainz bzw. der Universität Mainz.

Aus dem Abstract:

High-frequency oscillatory ventilation is looked upon as a lung-protective ventilation strategy. For a further clarification of the physical processes promoting gas transport, a visualization of gas flow and the distribution of ventilation are of considerable interest. Therefore, fluorine-19 magnetic resonance imaging of the imaging gas octafluorocyclobutane (C4F8) during high-frequency oscillatory ventilation was performed in five healthy pigs. For that, a mutually compatible ventilation-imaging system was set up and transverse images were acquired every 5 sec using FLASH sequences on a 1.5 T scanner. Despite a drop in signal-to-noise ratio after the onset of high-frequency oscillatory ventilation, for each pig, the four experiments could be analyzed. A mean wash-out time (t) at 5 Hz of 52.7 6 18 sec and 125.9 6 39 sec at 10 Hz, respectively, were found for regions of interest including the whole lung.
This is in agreement with the clinical findings, in that washout of respiratory gases is significantly prolonged for increased high-frequency oscillatory ventilation frequencies.
Our study could be a good starting-point for a further optimization of high-frequency oscillatory ventilation.

Erschienen ist der Artikel in der Zeitschrift Magnetic Resonance in Medicine, Volume 64, Issue 5, Seiten 1478-1483.

Artikel des Tages: High resolution lung airway cast segmentation with proper topology suitable for computational fluid dynamic simulations

Nach langer Abstinenz melde ich mich auch hier mal wieder, mit einem Artikel über MRT an der Lunge, der im Oktober 2010 in der Zeitschrift Computerized Medical Imaging and Graphics erschienen ist (Volume 34, Issue 7, Seiten 572-578).
Aus Zeitgründen nur mit Abstract:

Developing detailed lung airway models is an important step towards understanding the respiratory system. While modern imaging and airway casting approaches have dramatically improved the potential detail of such models, challenges have arisen in image processing as the demand for greater detail pushes the image processing approaches to their limits. Airway segmentations with proper topology have neither loops nor invalid voxel-to-voxel connections. Here we describe a new technique for segmenting airways with proper topology and apply the approach to an image volume generated by magnetic resonance imaging of a silicone cast created from an excised monkey lung.