In vivo MR imaging and spectroscopy using hyperpolarized 129Xe.
Hyperpolarized 129Xe has been used to obtain gas phase images of mouse lung in vivo, showing distinct ventilation variation as a function of the breathing cycle. Spectra of 129Xe in the thorax show complex structure in both the gas phase (-4 to 3 ppm) and tissue-dissolved (190-205 ppm) regions. The alveolar gas peak shows correlated intensity and frequency oscillations, both attributable to changes in lung volume during breathing. The two major dissolved peaks near 195-200 ppm are attributed to lung parenchyma and to blood; they reach maximum intensity in 5-10 s and decay with an apparent T1 of 30 s. Another peak at 190 ppm takes 20-30 s to reach maximum; this must represent other well-vascularized tissue (e.g., heart and other muscles) in the thorax. The maximum integrated area of the tissue components reaches 30-80% of the maximum alveolar gas area, indicating that imaging at tissue frequencies can be achieved.
Wagshul
M E
ME
Department of Radiology, State University of New York at Stony Brook 11794-8460, USA.
Button
T M
TM
Li
H F
HF
Liang
Z
Z
Springer
C S
CS
Zhong
K
K
Wishnia
A
A
D000818:Animals; D008168:Lung / Q000502:physiology*; D008176:Lung Volume Measurements; D008279:Magnetic Resonance Imaging / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods; D051379:Mice; D012119:Respiration / Q000502:physiology*; D014979:Xenon Isotopes
D014979:Xenon Isotopes