Lung imaging under free-breathing conditions.
Respiratory motion and pulsatile blood flow can generate artifacts in morphological and functional lung imaging. Total acquisition time, and thus the achievable signal to noise ratio, is limited when performing breath-hold and/or electrocardiogram-triggered imaging. To overcome these limitations, imaging during free respiration can be performed using respiratory gating/triggering devices or navigator echoes. However, these techniques provide only poor gating resolution and can induce saturation bands and signal fluctuations into the lung volume. In this work, acquisition schemes for nonphase encoded navigator echoes were implemented into different sequences for morphological and functional lung imaging at 1.5 Tesla (T) and 0.2T. The navigator echoes allow monitoring of respiratory motion and provide an ECG-trigger signal for correction of the heart cycle without influencing the imaged slices. Artifact free images acquired during free respiration using a 3D GE, 2D multislice TSE or multi-Gradient Echo sequence for oxygen-enhanced T(2)(*) quantification are presented.
Oechsner
Markus
M
Department of Experimental Physics 5, University of Würzburg, Würzburg, Germany. oechsner@physik.uni-wuerzburg.de
Pracht
Eberhard D
ED
Staeb
Daniel
D
Arnold
Johannes F T
JF
Köstler
Herbert
H
Hahn
Dietbert
D
Beer
Meinrad
M
Jakob
Peter M
PM
D000465:Algorithms; D016477:Artifacts; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods; D008168:Lung / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009038:Motion; D010363:Pattern Recognition, Automated / Q000379:methods; D015203:Reproducibility of Results; D015656:Respiratory Mechanics; D055425:Respiratory-Gated Imaging Techniques / Q000379:methods*; D012680:Sensitivity and Specificity