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Dietrich O, Gaass T, Reiser MF. T1 relaxation time constants, influence of oxygen, and the oxygen transfer function of the human lung at 1.5 T—A meta-analysis. Eur J Radiol 2017; 86:252-260. [DOI: 10.1016/j.ejrad.2016.11.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 11/22/2016] [Accepted: 11/23/2016] [Indexed: 12/13/2022]
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Stadler A, Jakob PM, Griswold M, Stiebellehner L, Barth M, Bankier AA. T1 mapping of the entire lung parenchyma: Influence of respiratory phase and correlation to lung function test results in patients with diffuse lung disease. Magn Reson Med 2008; 59:96-101. [PMID: 18098282 DOI: 10.1002/mrm.21446] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The T(1) values of lung parenchyma of 25 patients with fibrosis and emphysema were measured in the entire lung, and the effect of inspiration and expiration was investigated. T(1) map acquisition was based on a snapshot-fast low-angle shot (FLASH) sequence. Lung function and blood gas tests were measured. The study documents reverse respiratory phase dependence of T(1) measurements of the entire lung parenchyma in patients with emphysema and fibrosis. Furthermore, expiratory measurements showed higher and reverse differences between patient groups compared to inspiratory measurements. For the emphysema group, the average T(1) value in inspiration was 1033 +/- 74 ms. The average of the mean T(1) values in expiration was 982 +/- 56 ms. For the patients with fibrosis, the average T(1) value in inspiration was 996 +/- 103 ms. Compared to that, the average T(1) value in expiration was 1282 +/- 170 ms. Linear regression of T(1) vs. lung function parameters showed the highest regression coefficients for total lung capacity (TLC) and residual volume (RV) in expiration, the values were inversely proportionally dependent on the pooled expiratory T(1) values. These findings underline the strong but nonuniform influence of the inspirational status during T(1) measurements of the lung. T(1) maps in both emphysema and fibrosis should preferably be acquired at expiration if reliable data are to be obtained.
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Affiliation(s)
- Alfred Stadler
- Department of Radiology, Medical University of Vienna, Vienna, Austria.
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Voorhees A, An J, Berger KI, Goldring RM, Chen Q. Magnetic resonance imaging-based spirometry for regional assessment of pulmonary function. Magn Reson Med 2006; 54:1146-54. [PMID: 16217776 DOI: 10.1002/mrm.20682] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In this work MRI-based spirometry is presented as a method for noninvasively assessing pulmonary mechanical function on a regional basis. A SPAMM tagging sequence was modified to allow continuous dynamic imaging of the lungs during respiration. A motion-tracking algorithm was developed to track material regions from time-resolved grid-tagged images. Experiments were performed to image the lungs during quiet breathing and volumetric strain was calculated from the measured displacement maps. Regional volume calculations, derived from volumetric strain, were integrated over the entire lung and compared to segmented volume calculations with good agreement. Results from this work demonstrate that MRI spirometry has the potential to become a clinically useful tool for measuring regional ventilation and assessing pulmonary diseases that regionally affect the mechanical function of the lung.
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Affiliation(s)
- Abram Voorhees
- Department of Radiology, New York University School of Medicine, New York 10016-3240, USA.
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Bankier AA, O'Donnell CR, Mai VM, Storey P, De Maertelaer V, Edelman RR, Chen Q. Impact of lung volume on MR signal intensity changes of the lung parenchyma. J Magn Reson Imaging 2005; 20:961-6. [PMID: 15558552 DOI: 10.1002/jmri.20198] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
PURPOSE To test the hypothesis that, in magnetic resonance (MR) imaging of healthy individuals, equal relative changes in lung volume cause equal relative changes in MR signal intensity of the lung parenchyma. MATERIALS AND METHODS In two experimental runs, 10 volunteers underwent spirometrically monitored MR imaging of the lungs, with MR images acquired at 10 incremental lung volumes ranging from total lung capacity to 10% above residual volume. Average signal intensity, signal variability, and signal intensity integrals were calculated for each volunteer and for each lung volume. The effect of lung volume on signal intensity was quantified using linear regression analysis complemented by the runs test. Slopes and intercepts of regression lines were compared with an analysis of covariance. Slopes of the lines of best fit for lung volumes and signal intensities from the two runs were compared to the slope of the line of identity. Comparisons between the two runs were visualized using Bland and Altman plots. RESULTS The slopes of the 10 individual regression lines yielded no significant differences (F = 1.703, P = 0.101; F = 1.321, P = 0.239). The common slopes were -0.556 +/- 0.027 (P = 0.0001) for the first and -0.597 +/- 0.0031 (P = 0.0001) for the second experimental run. Both slopes displayed no significant nonlinearity (P = 0.419 and P = 0.067). There was a strong association between changes in lung volumes (rs = 0.991, P = 0.0001) and changes in signal intensity (rs = 0.889, P = 0.0001) in the two experimental runs. Lines of best fit for lung volume and signal intensities were not significantly different from the slope of the line of identity (P = 0.321 and P = 0.212, respectively). CONCLUSION Equal changes in lung volume cause equal changes in MR signal intensity of the lung parenchyma. This linear and reproducible phenomenon could be helpful in comparing pulmonary MR signal intensity between individuals.
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Stadler A, Jakob PM, Griswold M, Barth M, Bankier AA. T1 mapping of the entire lung parenchyma: Influence of the respiratory phase in healthy individuals. J Magn Reson Imaging 2005; 21:759-64. [PMID: 15906333 DOI: 10.1002/jmri.20319] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To determine the effect of respiratory phase on the T1 values of the entire lung. MATERIALS AND METHODS We calculated T1 relaxation time on a pixel-by-pixel analysis of a series of Snapshot FLASH tomograms acquired after a single inversion pulse. Two sets of coronal T1 maps were acquired, one in full suspended inspiration and one in suspended expiration. RESULTS The average of the mean T1 values over the entire lung in inspiration was 1199+/-117 msec, the average of the mean T1 values in expiration was 1333+/-167 msec. This difference was statistically significant, at P=0.005. In inspiration the average coefficient of variation was 182+/-56 msec, in expiration it was 153+/-41 msec. This difference was not statistically significant. CONCLUSION T1 measurements of the entire lung are feasible. Our findings underline the need for a close monitoring of the inspirational status during MR examinations of the thorax, notably when T1 measurements of the lung are performed.
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Affiliation(s)
- Alfred Stadler
- Department of Radiology, Medical University of Vienna, Vienna, Austria.
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Marzola P, Lanzoni A, Nicolato E, Di Modugno V, Cristofori P, Osculati F, Sbarbati A. 1H MRI of pneumococcal pneumonia in a murine model. J Magn Reson Imaging 2005; 22:170-4. [PMID: 15971184 DOI: 10.1002/jmri.20354] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To detect and quantify pulmonary lesions due to pneumococcal pneumonia in a murine model by (1)H MRI. MATERIALS AND METHODS Pneumonia was induced in mice (N = 5) by intranasal administration of about 1 x 10(6) colony-forming units (CFU) of Streptococcus pneumonie. A group of noninfected animals (N = 5) was used as a control group. MRI was performed, 48 hours after infection induction, at 4.7 T. ECG-gated gradient-echo (GRE) sequences with TE = 5 msec were used. After MRI examination, the animals were sacrificed for histological examination. RESULTS Lungs appeared at MRI as regions with signal intensity (SI) at the level of the noise. Lesions appeared as hyperintense regions over the background and were localized mainly in the apical part of the lungs, in the medial and peribronchial regions. The anatomical localization of the lesions was confirmed by histology. The total lesion volume quantified by MRI data correlated with the total lesion volume quantified by histology. CONCLUSION This work shows that standard (1)H MRI allows detection and quantification of lesions due to pneumococcal pneumonia in mice.
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Ohno Y, Oshio K, Uematsu H, Nakatsu M, Gefter WB, Hatabu H. Single-shot half-fourier RARE sequence with ultra-short inter-echo spacing for lung imaging. J Magn Reson Imaging 2004; 20:336-9. [PMID: 15269963 DOI: 10.1002/jmri.20107] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
PURPOSE To improve the image quality of pulmonary magnetic resonance (MR) imaging using an ultra-short inter-echo spacing half-Fourier single shot rapid acquisition with relaxation enhancement (USHA-RARE) sequence. MATERIALS AND METHODS Pulmonary MR images were acquired by USHA-RARE sequence with various inter-echo spacings. The sequence parameters were as follows: repetition time (TR)/effective TE: infinite/39-41 msec; section thickness: 10 mm; acquisition matrix: 128 x 128; field of view: 450 x 450 mm. Inter-echo spacing varied (2.5 msec, 3.0 msec, 3.5 msec, 4.0 msec, 4.5 msec, 5.0 msec), and the respective phase-encoding steps were 80, 77, 75, 74, 73, and 72. Signal-to-noise ratios (SNRs), the signal ratios between lung and fat (lung-to-fat ratio: LFRs), and the signal ratios between the lung and the serratus anterior muscle (lung-to-muscle ratio: LMRs) of each inter-echo spacing were calculated, and statistically evaluated. RESULTS The SNRs at inter-echo spacings of < or = 3.0 msec were significantly higher than those > or = 4.0 msec (P < 0.05). The LFRs and LMRs at inter-echo spacing < or = 3.0 msec were significantly higher than those > or = 4.0 msec (P < 0.05). CONCLUSION USHA-RARE sequence does improve signal intensity from the lung.
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Affiliation(s)
- Yoshiharu Ohno
- Pulmonary Functional Imaging Research, Department of Radiology, University of Pennsylvania Medical Center, Philadelphia, PA, USA.
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Jakob PM, Wang T, Schultz G, Hebestreit H, Hebestreit A, Elfeber M, Hahn D, Haase A. Magnetization transfer short inversion time inversion recovery enhanced 1H MRI of the human lung. MAGMA (NEW YORK, N.Y.) 2002; 15:10-7. [PMID: 12413560 DOI: 10.1007/bf02693839] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The unique characteristics of the human lung arising from low proton density and multiple air-tissue interfaces of the alveoli cause difficulty in 1H lung magnetic resonance imaging. In addition, the dominating signal from sources such as the thoracic muscle and subcutaneous fat hampers the visualization of the lung parenchyma. In this contribution, an efficient tissue suppression technique is presented which allows one to significantly enhance lung parenchyma visibility. A short inversion time inversion recovery (STIR) experiment combined with a magnetization transfer (MT) experiment was used for magnetization preparation in order to suppress the signal from muscle. A half-Fourier single-shot turbo spin-echo sequence was used as acquisition module. This approach was used to perform lung anatomical imaging in eight healthy human subjects and five patients with cystic fibrosis. The results obtained demonstrate that with MT-STIR approach high quality human lung images can be obtained and that this approach has the potential for the evaluation of lung pathologies.
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Affiliation(s)
- Peter M Jakob
- Department of Physics, Physikalisches Institut, EP 5, University of Würzburg, Am Hubland, D-97074, Würzburg, Germany.
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Mai VM, Liu B, Polzin JA, Li W, Kurucay S, Bankier AA, Knight-Scott J, Madhav P, Edelman RR, Chen Q. Ventilation-perfusion ratio of signal intensity in human lung using oxygen-enhanced and arterial spin labeling techniques. Magn Reson Med 2002; 48:341-50. [PMID: 12210943 DOI: 10.1002/mrm.10230] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This study investigates the distribution of ventilation-perfusion (V/Q) signal intensity (SI) ratios using oxygen-enhanced and arterial spin labeling (ASL) techniques in the lungs of 10 healthy volunteers. Ventilation and perfusion images were simultaneously acquired using the flow-sensitive alternating inversion recovery (FAIR) method as volunteers alternately inhaled room air and 100% oxygen. Images of the T(1) distribution were calculated for five volunteers for both selective (T(1f)) and nonselective (T(1)) inversion. The average T(1) was 1360 ms +/- 116 ms, and the average T(1f) was 1012 ms +/- 112 ms, yielding a difference that is statistically significant (P < 0.002). Excluding large pulmonary vessels, the average V/Q SI ratios were 0.355 +/- 0.073 for the left lung and 0.371 +/- 0.093 for the right lung, which are in agreement with the theoretical V/Q SI ratio. Plots of the V/Q SI ratio are similar to the logarithmic normal distribution obtained by multiple inert gas elimination techniques, with a range of ratios matching ventilation and perfusion. This MRI V/Q technique is completely noninvasive and does not involve ionized radiation. A limitation of this method is the nonsimultaneous acquisition of perfusion and ventilation data, with oxygen administered only for the ventilation data.
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Affiliation(s)
- Vu M Mai
- Department of Radiology, Evanston Hospital, Evanston Northwestern Healthcare, Illinois, USA.
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Mai VM, Liu B, Li W, Polzin J, Kurucay S, Chen Q, Edelman RR. Influence of oxygen flow rate on signal and T(1) changes in oxygen-enhanced ventilation imaging. J Magn Reson Imaging 2002; 16:37-41. [PMID: 12112501 DOI: 10.1002/jmri.10131] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To investigate the optimal oxygen flow rate for oxygen-enhanced MR ventilation imaging. MATERIALS AND METHODS Using a cardiac-triggered nonselective inversion recovery (IR) half Fourier single-shot fast spin echo sequence, series of images were acquired with the subject alternately inhaling room air and 100% oxygen. Oxygen flow rates of 5 L/min, 10 L/min, 15 L/min, 20 L/min, and 25 L/min were studied, and signal intensity from the oxygen-enhanced ventilation images and T(1) of the lung were measured. RESULTS The average signal intensity was 63.0 +/- 21.0 for 5 L/min, 98.7 +/- 26.8 for 10 L/min, 133.8 +/- 20.0 for 15 L/min, 138.7 +/- 19.7 for 20 L/min, and 139.2 +/- 37.9 for 25 L/min. The average T(1)'s of the lung were 1399 msec +/- 130 msec for room air, 1314 msec +/- 101 msec for 5 L/min, 1276 msec +/- 105 msec for 10 L/min, 1207 msec +/- 71 msec for 15 L/min, 1206 msec +/- 90 msec for 20 L/min, and 1207 msec +/- 42 msec for 25 L/min. CONCLUSION The optimal flow rate is 15 L/min for oxygen-enhanced ventilation imaging.
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Affiliation(s)
- Vu M Mai
- Department of Radiology, Evanston Hospital, Evanston Northwestern Healthcare, Illinois 60201, USA.
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Current awareness. NMR IN BIOMEDICINE 2002; 15:75-86. [PMID: 11840556 DOI: 10.1002/nbm.746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Jakob PM, Hillenbrand CM, Wang T, Schultz G, Hahn D, Haase A. Rapid quantitative lung (1)H T(1) mapping. J Magn Reson Imaging 2001; 14:795-9. [PMID: 11747038 DOI: 10.1002/jmri.10024] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
In this contribution, a rapid and robust technique for quantitative T(1) mapping of the human lung is presented. Based on a series of Snapshot FLASH tomograms acquired after a single inversion pulse, high quality and quantitative T(1) parameter maps acquired in under five seconds were obtained from six healthy volunteers. The measured T(1) values are in good agreement with previously reported literature values. T(1) maps were also acquired with the volunteers breathing room air or 100% O(2). The T(1) difference between breathing room air and 100% O(2) is statistically significant at P < 0.0001.
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Affiliation(s)
- P M Jakob
- Department of Physics, University of Würzburg, Würzburg, Germany.
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Mai VM, Bankier AA, Prasad PV, Li W, Storey P, Edelman RR, Chen Q. MR ventilation-perfusion imaging of human lung using oxygen-enhanced and arterial spin labeling techniques. J Magn Reson Imaging 2001; 14:574-9. [PMID: 11747009 DOI: 10.1002/jmri.1221] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Magnetic resonance ventilation-perfusion (V/Q) imaging has been demonstrated using oxygen and arterial spin labeling techniques. Inhaled oxygen is used as a paramagnetic contrast agent in ventilation imaging using a multiple inversion recovery (MIR) approach. Pulmonary perfusion imaging is conducted using a flow-sensitive alternating inversion recovery with an extra radiofrequency pulse (FAIRER) technique. A half Fourier single-short turbo spin echo (HASTE) sequence is used for data acquisition in both techniques. V/Q imaging was performed in ten of the twenty volunteers, while either ventilation or perfusion was imaged in the other ten. This V/Q imaging scheme is completely noninvasive, does not involve ionized radiation, and shows promising potential for clinical use in the diagnosis of lung diseases such as pulmonary embolism.
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Affiliation(s)
- V M Mai
- Department of Radiology, Evanston Northwestern Healthcare and Northwestern University, Evanston, Illinois 60201, USA.
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Beckmann N, Tigani B, Mazzoni L, Fozard JR. MRI of lung parenchyma in rats and mice using a gradient-echo sequence. NMR IN BIOMEDICINE 2001; 14:297-306. [PMID: 11477650 DOI: 10.1002/nbm.706] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Signal of lung parenchymal tissue from the living rat and mouse lung was detected at 4.7 T with a good signal-to-noise ratio and motion-suppressed artifacts using a short TE gradient-echo sequence. Neither cardiac nor respiratory gating were applied, and animals respired freely during data collection. Mean T(2)* relaxation times of parenchyma in the anterior, middle and posterior regions of both lungs ranged between 403 and 657 micros and 397 and 751 micros, respectively for the rat and mouse. For the rat in the prone position, there was a gradient in T(2)* values, from the posterior to the anterior regions of both lungs. In the supine position, however, T(2)* values were larger in the posterior and in the anterior portions. For the mouse in both prone and supine positions, there was a tendential gradient in T(2)* from the anterior to the posterior portions. The robustness of the approach renders it well suited for routine applications, e.g. in pharmacological studies concerning asthma models in small rodents. The method was applied to lung inflammation models involving challenge with ovalbumin or lipopolysaccharide.
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Affiliation(s)
- N Beckmann
- Core Technologies Area, Novartis Pharma AG, Analytics and Imaging Sciences Unit, CH-4002 Basel, Switzerland.
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