Navigator-triggered oxygen-enhanced MRI with simultaneous cardiac and respiratory synchronization for the assessment of interstitial lung disease.
OBJECTIVE
To evaluate an optimized method for oxygen-enhanced MRI of the lung, using simultaneous electrocardiograph (ECG) and navigator triggering. To correlate oxygen-enhanced MRI with lung function tests assessing alveolar-capillary gas exchange.


METHODS
A total of 12 healthy volunteers (aged 20-32 years) and 10 patients (aged 37-87 years) with interstitial lung diseases (ILD) underwent oxygen-enhanced MRI and pulmonary functional tests (PFTs) assessing alveolar-capillary gas exchange. The paradigm room-air-oxygen-room-air was acquired with a nonselective inversion-recovery half-Fourier single-shot turbo spin-echo sequence (inversion time = 1200 msec; acquisition time = 134.5 msec; slice thickness = 20 mm; matrix size = 128 x 128), using simultaneous double triggering (navigator plus ECG trigger). Cross-correlation was performed in regions of interest (ROIs) encompassing both lungs. The number of oxygen-activated pixels over the total number of pixels in the ROIs (OAP%) of volunteers and patients was compared. OAP%s were correlated with PFTs.


RESULTS
The mean OAP% of patients was significantly lower than that of volunteers (36.7 vs. 81.7, P = 0.001). OAP% correlated with the transfer lung factor for carbon monoxide (Tlco) (r = 0.64; P = 0.002), the transfer coefficient (Kco) (r = 0.75; P = 0.001), the arterial partial pressure (r = 0.77; P < 0.001), and the saturation (r = 0.70; P < 0.001) of oxygen.


CONCLUSIONS
Navigator-triggered oxygen-enhanced MRI of the lung may have a potential role in the quantitative assessment of lung function in ILD.
Molinari
Francesco
F
Department of Bioimaging and Radiological Sciences, Catholic University of Rome, Rome, Italy.
Eichinger
Monika
M
Risse
Frank
F
Plathow
Christian
C
Puderbach
Michael
M
Ley
Sebastian
S
Herth
Felix
F
Bonomo
Lorenzo
L
Kauczor
Hans-Ulrich
HU
Fink
Christian
C
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004562:Electrocardiography; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D017563:Lung Diseases, Interstitial / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000378:metabolism; D011659:Pulmonary Gas Exchange; D012129:Respiratory Function Tests; D015656:Respiratory Mechanics; D018709:Statistics, Nonparametric
D010100:Oxygen