MR microimaging of the lung using volume projection encoding

✍ Scribed by Mark D. Shattuck; Sally L. Gewalt; Gary H. Glover; Laurence W. Hedlund; G. Allan Johnson

• Book ID: 102957480
• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 525 KB
• Volume: 38
• Category: Article
• ISSN: 0740-3194
• DOI: 10.1002/mrm.1910380613

✦ Synopsis

Abstract

Radial acquisition (RA) techniques have been extended to produce isotropic, three‐dimensional images of lung in live laboratory animals at spatial resolution down to 0.013 mm^3^ with a signal‐to‐noise ratio of 30:1. The pulse sequence and reconstruction algorithm have been adapted to allow acquisition of image matrices of up to 256^3^ in less than 15 min. Scan‐synchronous ventilation has been incorporated to limit breathing motion artifacts. The imaging sequence permits randomizing and/or discarding selected views to minimize the consequences of breathing motion. The signal in lung parenchyma was measured as a function of flip angle (α) for different repetition times and found to follow the predictions for which there is an optimum excitation (Ernst) angle. A single T~1~, relaxation value of 780 ± 54 ms fits all data from six guinea pigs at 2.0 T. This T~1~, value parameterizes the signal and allows for a priori optimization, such as calculation of the Ernst angle appropriate for lung imaging.