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MR microscopy of lung airways with hyperpolarized 3 He
Author(s) -
Chen X. Josette,
Chawla Mark S.,
Hedlund Laurence W.,
Möller Harald E.,
Macfall James R.,
Johnson G. Allan,
G. Elaine
Publication year - 1998
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.1910390113
Subject(s) - lung , airway , guinea pig , flip angle , nuclear magnetic resonance , materials science , nuclear medicine , magnetic resonance imaging , medicine , physics , radiology , surgery
A technique using hyperpolarized (HP) 3 He to image the small airways of the lung by using moderate flip angles and a short scanning period during early inspiration is demonstrated. Flip angles (α) ranging from 10–90° were used in guinea pig experiments with scanning during the entire inspiration period. A second series acquired data throughout a short window of the ventilatory cycle with α= 45°. The success of the animal studies has motivated implementation of similar imaging techniques in the clinical arena. Human studies involved imaging over the total inspiration period with α ≈ 10°. The first series of guinea pig experiments demonstrated that larger flip angles (50‐90°) destroy the magnetization before it reaches the smaller airways. At moderate flip angles (20‐40°), airway branching down to the fourth generation was apparent. Fifth‐order branchings were seen in the images of the second series. The trachea down to fourth generation pulmonary airway branching, along with some distal air spaces, was seen in the human lung images.