Oxygen-Enhanced MRI of the Lungs: Intraindividual Comparison Between 1.5 and 3 Tesla

Zusammenfassung

Ziel: Die Machbarkeit der sauerstoffverstärkten MRT der Lunge bei 3 Tesla sollte beurteilt und die Signalcharakteristika mit 1,5 Tesla verglichen werden. Material und Methoden: 13 Probanden unterzogen sich einer sauerstoffverstärkten MRT-Untersuchung bei 1,5 und 3 T mit einer koronar orientierten T 1-gewichteten, einschichtigen, nichtselektiven Inversion-Recovery-Half-Fourier-Fast-Spin-Echo-Sequenz mit Atem- und EKG-Triggerung. Je 40 Einzelmessungen wurden unter Raumluftatmung und unter Sauerstoffatmung (15 l/min über eine Atemmaske) durchgeführt. Das Signal-Rausch-Verhältnis (SNR) von Lungengewebe wurde mithilfe eines Differenzbildverfahrens ermittelt. Die Bildqualität der Einzelakquisitionen wurde visuell beurteilt. Der Mittelwert des sauerstoffvermittelten relativen Signalanstiegs und sein regionaler Variationskoeffizient wurden berechnet und der Signalanstieg in Parameterkarten farbcodiert dargestellt. Verteilung und Heterogenität des Signalanstiegs in den Parameterkarten bei beiden Feldstärken wurden visuell verglichen. Ergebnisse: Der mittlere relative Signalanstieg durch Sauerstoffatmung betrug 13 % (± 5.6 %) bei 1,5 T und 9.0 % (± 8.0 %) bei 3 T. Ein signifikant höherer Wert des regionalen Variationskoeffizienten zeigte sich bei 3 T. Auf den Parameterkarten zeigte sich visuell und quantitativ bei 3 T eine deutlich inhomogenere Verteilung des Signalanstiegs. Das SNR unterschied sich bei den beiden Feldstärken nicht signifikant, war jedoch bei 3 T tendenziell (um ca. 10 %) höher. Schlussfolgerung: Die sauerstoffverstärkte MRT-Bildgebung der Lunge lässt sich prinzipiell bei 3 T durchführen, wenngleich der Signalanstieg bei 3 T derzeit im Vergleich zu 1,5 T heterogener und etwas geringer ist.

Abstract

Purpose: To assess the feasibility of oxygen-enhanced MRI of the lung at 3 Tesla and to compare signal characteristics with 1.5 Tesla. Materials and Methods: 13 volunteers underwent oxygen-enhanced lung MRI at 1.5 and 3 T with a T 1-weighted single-slice non-selective inversion-recovery single-shot half-Fourier fast-spin-echo sequence with simultaneous respiratory and cardiac triggering in coronal orientation. 40 measurements were acquired during room air breathing and subsequently during oxygen breathing (15 L/min, close-fitting face-mask). The signal-to-noise ratio (SNR) of the lung tissue was determined with a difference image method. The image quality of all acquisitions was visually assessed. The mean values of the oxygen-induced relative signal enhancement and its regional coefficient of variation were calculated and the signal enhancement was displayed as color-coded parameter maps. Oxygen-enhancement maps were visually assessed with respect to the distribution and heterogeneity of the oxygen-related signal enhancement at both field strengths. Results: The mean relative signal enhancement due to oxygen breathing was 13 % (± 5.6 %) at 1.5 T and of 9.0 % (± 8.0 %) at 3 T. The regional coefficient of variation was significantly higher at 3 T. Visual and quantitative assessment of the enhancement maps showed considerably less homogeneous distribution of the signal enhancement at 3 T. The SNR was not significantly different but showed a trend to slightly higher values (increase of about 10 %) at 3 T. Conclusion: Oxygen-enhanced pulmonary MRI is feasible at 3 Tesla. However, signal enhancement is currently more heterogeneous and slightly lower at 3 T.

3 Tesla MRI - oxygen-enhanced lung MRI - lung MRI - high-field lung MRI

References

• 1 Edelman R R, Hatabu H, Tadamura E et al. Noninvasive assessment of regional ventilation in the human lung using oxygen-enhanced magnetic resonance imaging.  Nat Med. 1996;  2 1236-1239
• 2 Ohno Y, Chen Q, Hatabu H. Oxygen-enhanced magnetic resonance ventilation imaging of lung.  Eur J Radiol. 2001;  37 164-171
• 3 Ohno Y, Hatabu H. Basics concepts and clinical applications of oxygen-enhanced MR imaging.  Eur J Radiol. 2007;  64 320-328
• 4 Muller C J, Schwaiblmair M, Scheidler J et al. Pulmonary diffusing capacity: assessment with oxygen-enhanced lung MR imaging preliminary findings.  Radiology. 2002;  222 499-506
• 5 Nakagawa T, Sakuma H, Murashima S et al. Pulmonary ventilation-perfusion MR imaging in clinical patients.  J Magn Reson Imaging. 2001;  14 419-424
• 6 Arnold J F, Kotas M, Fidler F et al. Quantitative regional oxygen transfer imaging of the human lung.  J Magn Reson Imaging. 2007;  26 637-645
• 7 Dietrich O, Losert C, Attenberger U et al. Fast oxygen-enhanced multislice imaging of the lung using parallel acquisition techniques.  Magn Reson Med. 2005;  53 1317-1325
• 8 Bergin C J, Glover G H, Pauly J M. Lung parenchyma: magnetic susceptibility in MR imaging.  Radiology. 1991;  180 845-848
• 9 Fink C, Puderbach M, Biederer J et al. Lung MRI at 1.5 and 3 Tesla: observer preference study and lesion contrast using five different pulse sequences.  Invest Radiol. 2007;  42 377-383
• 10 Molinari F, Eichinger M, Risse F et al. Navigator-triggered oxygen-enhanced MRI with simultaneous cardiac and respiratory synchronization for the assessment of interstitial lung disease.  J Magn Reson Imaging. 2007;  26 1523-1529
• 11 Molinari F, Gaudino S, Fink C et al. Simultaneous cardiac and respiratory synchronization in oxygen-enhanced magnetic resonance imaging of the lung using a pneumotachograph for respiratory monitoring.  Invest Radiol. 2006;  41 476-485
• 12 Vaninbroukx J, Bosmans H, Sunaert S et al. The use of ECG and respiratory triggering to improve the sensitivity of oxygen-enhanced proton MRI of lung ventilation.  Eur Radiol. 2003;  13 1260-1265
• 13 Molinari F, Puderbach M, Eichinger M et al. Oxygen-enhanced magnetic resonance imaging: influence of different gas delivery methods on the T 1-changes of the lungs.  Invest Radiol. 2008;  43 427-432
• 14 Prisk G K, Yamada K, Henderson A C et al. Pulmonary perfusion in the prone and supine postures in the normal human lung.  J Appl Physiol. 2007;  103 883-894
• 15 Ohno Y, Oshio K, Uematsu H et al. Single-shot half-Fourier RARE sequence with ultra-short inter-echo spacing for lung imaging.  J Magn Reson Imaging. 2004;  20 336-339
• 16 Mai V M, Liu B, Li W et al. Influence of oxygen flow rate on signal and T(1) changes in oxygen-enhanced ventilation imaging.  J Magn Reson Imaging. 2002;  16 37-41
• 17 Bankier A A, O’Donnell C R, Mai V M et al. Impact of lung volume on MR signal intensity changes of the lung parenchyma.  J Magn Reson Imaging. 2004;  20 961-966
• 18 Dietrich O, Raya J G, Reeder S B et al. Measurement of signal-to-noise ratios in MR images: influence of multichannel coils, parallel imaging, and reconstruction filters.  J Magn Reson Imaging. 2007;  26 375-385
• 19 Dehnert C, Risse F, Ley S et al. Magnetic resonance imaging of uneven pulmonary perfusion in hypoxia in humans.  American journal of respiratory and critical care medicine. 2006;  174 1132-1138
• 20 Levin D L, Buxton R B, Spiess J P et al. Effects of age on pulmonary perfusion heterogeneity measured by magnetic resonance imaging.  J Appl Physiol. 2007;  102 2064-2070
• 21 Hintze C, Stemmer A, Bock M et al. A hybrid breath hold and continued respiration-triggered technique for time-resolved 3D MRI perfusion studies in lung cancer.  Fortschr Röntgenstr. 2010;  182 45-52
• 22 Ley-Zaporozhan J, Ley S, Sommerburg O et al. Clinical application of MRI in children for the assessment of pulmonary diseases.  Fortschr Röntgenstr. 2009;  181 419-432
• 23 Tetzlaff R, Eichinger M, Schobinger M et al. Semiautomatic assessment of respiratory motion in dynamic MRI – comparison with simultaneously acquired spirometry.  Fortschr Röntgenstr. 2008;  180 961-967
• 24 Wolf T, Anjorin A, Posselt H et al. MRT-basierte Flussmessungen im Truncus pulmonalis zur Detektion einer pulmonal-arteriellen Hypertonie in Patienten mit zystischer Fibrose.  Fortschr Röntgenstr. 2009;  181 139-146
• 25 Nael K, Michaely H J, Lee M et al. Dynamic pulmonary perfusion and flow quantification with MR imaging, 3.0 T vs. 1.5 T: initial results.  J Magn Reson Imaging. 2006;  24 333-339
• 26 Nael K, Saleh R, Nyborg G K et al. Pulmonary MR perfusion at 3.0 Tesla using a blood pool contrast agent: Initial results in a swine model.  J Magn Reson Imaging. 2007;  25 66-72
• 27 Ohno Y, Koyama H, Nogami M et al. Dynamic oxygen-enhanced MRI versus quantitative CT: pulmonary functional loss assessment and clinical stage classification of smoking-related COPD.  Am J Roentgenol. 2008;  190 W93-99
• 28 Ohno Y, Iwasawa T, Seo J B et al. Oxygen-enhanced magnetic resonance imaging versus computed tomography: multicenter study for clinical stage classification of smoking-related chronic obstructive pulmonary disease.  American journal of respiratory and critical care medicine. 2008;  177 1095-1102
• 29 Stock K W, Chen Q, Morrin M et al. Oxygen-enhanced magnetic resonance ventilation imaging of the human lung at 0.2 and 1.5T.  J Magn Reson Imaging. 1999;  9 838-841
• 30 Loffler R, Muller C J, Peller M et al. Optimization and evaluation of the signal intensity change in multisection oxygen-enhanced MR lung imaging.  Magn Reson Med. 2000;  43 860-866
• 31 Chen Q, Jakob P M, Griswold M A et al. Oxygen enhanced MR ventilation imaging of the lung.  MAGMA Magn Reson Mater Phy. 1998;  7 153-161
• 32 Jakob P M, Hillenbrand C M, Wang T et al. Rapid quantitative lung (1)H T(1) mapping.  J Magn Reson Imaging. 2001;  14 795-799
• 33 Nichols M B, Paschal C B. Measurement of longitudinal (T1) relaxation in the human lung at 3.0 Tesla with tissue-based and regional gradient analyses.  J Magn Reson Imaging. 2008;  27 224-228
• 34 Dietrich O, Raya J G, Fasol U et al. Oxygen-enhanced MRI of the lung at 3 Tesla: Feasibility and T 1 relaxation times.  Proceedings of the International Society for Magnetic Resonance in Medicine (ISMRM). 2006;  14 1307
• 35 Dietrich O, Reiser M F, Schoenberg S O. Artifacts in 3-T MRI: physical background and reduction strategies.  Eur J Radiol. 2008;  65 29-35
• 36 Puderbach M, Ohno Y, Kawamitsu H et al. Influence of inversion pulse type in assessing lung-oxygen-enhancement by centrically-reordered non-slice-selective inversion-recovery half-Fourier single-shot turbo spin-echo (HASTE) sequence.  J Magn Reson Imaging. 2007;  26 1133-1138