FREE BREATHING DYNAMIC 19F MR IMAGING OF LUNGS USING
OCTAFLUOROCYCLOBUTANE AT 1.5 T
Gulyaev M.V.1, Pavlova O.S.1,2, Rudenko A.Yu.3, Ozhiganov R.M.4, Dmitriev D.S.5,
Pistrak A.G.5, Ryabikov K.N.5, Tarasov V.P.5,6, Pirogov Y.A.2
1 – Faculty of Medicine, Lomonosov Moscow State University. Moscow, Russia.
2 – Faculty of Physics, Lomonosov Moscow State University. Moscow, Russia.
3 – Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University. Moscow, Russia.
4 – Higher Chemical College of the Russian Academy of Sciences, Mendeleev University of Chemical Technology of Russia.
Moscow, Russia.
5 – «S.P. HELPIC» LTD. Moscow, Russia.
6 – Federal Research Center of Problems of Chemical Physics and Medicinal Chemistry Russian Academy of Sciences.
Moscow region, Chernogolovka, Russia.
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urpose. To obtain the information about lung function in humans with octafluorocyclobutane (C4F8, OFCB) using 19F MRI at 1.5 T.
Materials and methods. We carried out this work on a laboratory bench with a 1.5 T magnet and open source software. The resonant frequency of the conventional 1H RF coils (~63.8 MHz) has been retuned to the resonant frequency of 19F (~60 MHz). To minimize the consumption of fluorinated gas, a gas mixture installation was designed and tested on one healthy volunteer. Two methods for assessing pulmonary function were implemented: wash-in/wash-out dynamics and single-breath imaging. The wash-in/wash-out dynamics technique was implemented using short breaths of the gas mixture (70% OFCB and 30% O2) and then air, respectively. The single-breath imaging was realized on one prolonged inhalation and exhalation of the gas mixture.
Results. The t-maps (effective time maps) and FV-maps (fractional ventilation maps) of the lungs were constructed. The FV values of the lungs were calculated: FVwash-in = 0.30 ± 0.06 and FVinsp = 0.34 ± 0.06 (for the wash-in and single-breath method, respectively); FVwash-out = 0.35 ± 0.04 and FVexp = 0.45 ± 0.06 (for the wash-out and single-breath method, respectively).
Discussion. This work builds on our previous work that assessed lung function with OFCB using 19F MRI at 0.5 T. In this paper, we implemented the 19F MRI studies for the assessment of pulmonary function on a 1.5 T MRI scanner. We solved the problem of retuning the RF coils to the 19F resonant frequency and developed a gas delivery system that can be used repeatedly for different patients – just replace the nozzle to inhale/exhale the gas mixture. We showed that the FV values calculated for a healthy volunteer are standard and were obtained previously using another fluorinated gas perfluoropropane.
Conclusion. We conclude that the use of OFCB provides informative 19F MR images for the assessment of pulmonary function at 1.5 T.
Keywords: 19F MRI, lungs, octafluorocyclobutane, wash-in, wash-out, single-breath.
Corresponding author: Gulyaev M.V., e-mail: Этот e-mail адрес защищен от спам-ботов, для его просмотра у Вас должен быть включен Javascript
For citation: Gulyaev M.V., Pavlova O.S., Rudenko A.Yu., Ozhiganov R.M., Dmitriev D.S., Pistrak A.G., Ryabikov K.N., Tarasov V.P., Pirogov Y.A. Free breathing dynamic 19F MR imaging of lungs using octafluorocyclobutane at 1.5 t. REJR 2024; 14(2):57-68. DOI: 10.21569/2222-7415-2024-14-2-57-68.
Received: 08.02.24 Accepted: 05.04.24