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Lin Q, Cheng C, Bao Y, Liu WV, Zhang L, Cai Z, Wan Q, Sun C, Li X, Deng Y. A clinically-recommended MR whole lung imaging protocol using free-breathing 3D isotropic zero echo time sequence. Heliyon 2024; 10:e34098. [PMID: 39071690 PMCID: PMC11282979 DOI: 10.1016/j.heliyon.2024.e34098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Revised: 06/30/2024] [Accepted: 07/03/2024] [Indexed: 07/30/2024] Open
Abstract
Rationale and objectives This study aimed to assess the feasibility and image quality of free-breathing 3D isotropic zero echo time (ZTE) whole-lung imaging and explore a clinically appropriate protocol for MR lung imaging. Materials and methods The study was approved by the local ethics committee. A total of thirty healthy volunteers were enrolled in this study from October 2022 to May 2023. Free-breathing pulmonary 3D isotropic ZTE scans were implemented with various acquisition planes and the number of excitations (NEX). ZTE images were evaluated by two radiologists for the overall Image quality and visibility of intrapulmonary structures as well as the signal-to-noise ratio (SNR) of the lung parenchyma. ZTE images with different acquisition parameters were compared. For preliminary clinical visual assessment, three patients with interstitial lung disease underwent both ZTE imaging and computed tomography (CT). Results The overall image quality of the lung in healthy subjects was good to excellent. The visibilities of pulmonary arteries and bronchus were up to the 7th and 5th generation, respectively. The display of lung fissures was poor. The overall image quality, the visibility of the pulmonary artery, and lung fissures in the axial acquisition were better than in the coronal acquisition (P = 0.011, 0.008, 0.010, respectively) but not statistically different from those in the sagittal acquisition (all P > 0.05). Conclusion The free-breathing pulmonary ZTE is feasible and may serve as an alternative method in chest imaging. Either axial or sagittal ZTE image acquisition would be preferred in clinical practice.
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Affiliation(s)
- Qiuxi Lin
- Department of Radiology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510120, China
| | - Cheng Cheng
- Department of Radiology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510120, China
- Department of Radiology, LIWAN Central Hospital of GUANGZHOU, 510120, China
| | - Yingying Bao
- Department of Radiology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510120, China
| | | | - Lei Zhang
- MR Research, GE Healthcare, Beijing, 100176, China
| | - Zhaofeng Cai
- Department of Radiology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510120, China
| | - Qi Wan
- Department of Radiology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510120, China
| | - Chongpeng Sun
- Department of Radiology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510120, China
| | - Xinchun Li
- Department of Radiology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510120, China
| | - Yu Deng
- Department of Radiology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510120, China
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Tarchi SM, Salvatore M, Lichtenstein P, Sekar T, Capaccione K, Luk L, Shaish H, Makkar J, Desperito E, Leb J, Navot B, Goldstein J, Laifer S, Beylergil V, Ma H, Jambawalikar S, Aberle D, D'Souza B, Bentley-Hibbert S, Marin MP. Radiology of fibrosis. Part I: Thoracic organs. J Transl Med 2024; 22:609. [PMID: 38956586 PMCID: PMC11218337 DOI: 10.1186/s12967-024-05244-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 04/27/2024] [Indexed: 07/04/2024] Open
Abstract
Sustained injury from factors such as hypoxia, infection, or physical damage may provoke improper tissue repair and the anomalous deposition of connective tissue that causes fibrosis. This phenomenon may take place in any organ, ultimately leading to their dysfunction and eventual failure. Tissue fibrosis has also been found to be central in both the process of carcinogenesis and cancer progression. Thus, its prompt diagnosis and regular monitoring is necessary for implementing effective disease-modifying interventions aiming to reduce mortality and improve overall quality of life. While significant research has been conducted on these subjects, a comprehensive understanding of how their relationship manifests through modern imaging techniques remains to be established. This work intends to provide a comprehensive overview of imaging technologies relevant to the detection of fibrosis affecting thoracic organs as well as to explore potential future advancements in this field.
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Affiliation(s)
- Sofia Maria Tarchi
- Department of Biomedical Sciences, Humanitas University, Milan, Italy.
- Department of Radiology, Columbia University Irving Medical Center, 630 W 168th Street, New York, NY, 10032, USA.
| | - Mary Salvatore
- Department of Radiology, Columbia University Irving Medical Center, 630 W 168th Street, New York, NY, 10032, USA
| | - Philip Lichtenstein
- Department of Radiology, Columbia University Irving Medical Center, 630 W 168th Street, New York, NY, 10032, USA
| | - Thillai Sekar
- Department of Radiology, Columbia University Irving Medical Center, 630 W 168th Street, New York, NY, 10032, USA
| | - Kathleen Capaccione
- Department of Radiology, Columbia University Irving Medical Center, 630 W 168th Street, New York, NY, 10032, USA
| | - Lyndon Luk
- Department of Radiology, Columbia University Irving Medical Center, 630 W 168th Street, New York, NY, 10032, USA
| | - Hiram Shaish
- Department of Radiology, Columbia University Irving Medical Center, 630 W 168th Street, New York, NY, 10032, USA
| | - Jasnit Makkar
- Department of Radiology, Columbia University Irving Medical Center, 630 W 168th Street, New York, NY, 10032, USA
| | - Elise Desperito
- Department of Radiology, Columbia University Irving Medical Center, 630 W 168th Street, New York, NY, 10032, USA
| | - Jay Leb
- Department of Radiology, Columbia University Irving Medical Center, 630 W 168th Street, New York, NY, 10032, USA
| | - Benjamin Navot
- Department of Radiology, Columbia University Irving Medical Center, 630 W 168th Street, New York, NY, 10032, USA
| | - Jonathan Goldstein
- Department of Radiology, Columbia University Irving Medical Center, 630 W 168th Street, New York, NY, 10032, USA
| | - Sherelle Laifer
- Department of Radiology, Columbia University Irving Medical Center, 630 W 168th Street, New York, NY, 10032, USA
| | - Volkan Beylergil
- Department of Radiology, Columbia University Irving Medical Center, 630 W 168th Street, New York, NY, 10032, USA
| | - Hong Ma
- Department of Radiology, Columbia University Irving Medical Center, 630 W 168th Street, New York, NY, 10032, USA
| | - Sachin Jambawalikar
- Department of Radiology, Columbia University Irving Medical Center, 630 W 168th Street, New York, NY, 10032, USA
| | - Dwight Aberle
- Department of Radiology, Columbia University Irving Medical Center, 630 W 168th Street, New York, NY, 10032, USA
| | - Belinda D'Souza
- Department of Radiology, Columbia University Irving Medical Center, 630 W 168th Street, New York, NY, 10032, USA
| | - Stuart Bentley-Hibbert
- Department of Radiology, Columbia University Irving Medical Center, 630 W 168th Street, New York, NY, 10032, USA
| | - Monica Pernia Marin
- Department of Radiology, Columbia University Irving Medical Center, 630 W 168th Street, New York, NY, 10032, USA
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3
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Bozovic G, Schaefer-Prokop CM, Bankier AA. Pulmonary functional imaging (PFI): A historical review and perspective. Acta Radiol 2022; 64:90-100. [PMID: 35118881 DOI: 10.1177/02841851221076324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PFI Pulmonary Functional Imaging (PFI) refers to visualization and measurement of ventilation, perfusion, gas flow and exchange as well as biomechanics. In this review, we will highlight the historical development of PFI, describing recent advances and listing the various techniques for PFI offered per modality. Challenges PFI is facing and requirements for PFI from a clinical point of view will be pointed out. Hereby the review is meant as an introduction to PFI.
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Affiliation(s)
- Gracijela Bozovic
- Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Cornelia M Schaefer-Prokop
- Department of Radiology, Meander Medical Centre, TZ Amersfoort, The Netherlands
- Department of Radiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Alexander A Bankier
- Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA
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4
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Salamon E, Lever S, Kuo W, Ciet P, Tiddens HAWM. Spirometer guided chest imaging in children: It is worth the effort! Pediatr Pulmonol 2017; 52:48-56. [PMID: 27273821 DOI: 10.1002/ppul.23490] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 04/28/2016] [Accepted: 05/06/2016] [Indexed: 12/12/2022]
Abstract
PURPOSE Computed tomography (CT) and magnetic resonance imaging (MRI) scans are used to assess and monitor several pediatric lung diseases. It is well recognized that lung volume at the moment of acquisition has a major impact on the appearance of lung parenchyma and airways. Importantly, the sensitivity of chest CT and MRI to detect bronchiectasis and gas trapping is highly dependent on adequate volume control during the image acquisition. This paper describes a feasible method to obtain accurate control of lung volume during chest imaging in pediatric patients with lung disease. PROCEDURE A procedure to obtain maximal respiratory manoeuvres with spirometry guidance during image acquisition for CT and MRI is described. This procedure requires training of the subject, an MRI compatible spirometer and close collaboration between a lung function scientist and the radiographer. A good to excellent target volume level for the inspiratory or expiratory scan can be achieved in around 90% of children. An important condition for this success rate is the training of the subject, executed prior to each chest CT or MRI, and instructions by the lung function scientist during the chest CT. CONCLUSION Implementing lung volume guidance with a spirometer is an important and feasible step to standardize chest imaging and to optimize the diagnostic yield of chest CT and MRI in children with lung disease. Training and the collaborative effort by a lung function scientist and radiographer is the key factor for success of this procedure. Pediatr Pulmonol. 2017;52:48-56. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Elizabeth Salamon
- Department of Pediatric Pulmonology, Erasmus Medical Center, Sophia Children's Hospital, Dr. Molewaterplein 60, Room SP-3464, 3015 GJ, Rotterdam, The Netherlands
| | - Sandra Lever
- Department of Pediatric Pulmonology, Erasmus Medical Center, Sophia Children's Hospital, Dr. Molewaterplein 60, Room SP-3464, 3015 GJ, Rotterdam, The Netherlands
| | - Wieying Kuo
- Department of Pediatric Pulmonology, Erasmus Medical Center, Sophia Children's Hospital, Dr. Molewaterplein 60, Room SP-3464, 3015 GJ, Rotterdam, The Netherlands.,Department of Radiology, Erasmus Medical Center, Dr. Molewaterplein 60, Room SP-3464, 3015 GJ, Rotterdam, The Netherlands
| | - Pierluigi Ciet
- Department of Pediatric Pulmonology, Erasmus Medical Center, Sophia Children's Hospital, Dr. Molewaterplein 60, Room SP-3464, 3015 GJ, Rotterdam, The Netherlands.,Department of Radiology, Erasmus Medical Center, Dr. Molewaterplein 60, Room SP-3464, 3015 GJ, Rotterdam, The Netherlands
| | - Harm A W M Tiddens
- Department of Pediatric Pulmonology, Erasmus Medical Center, Sophia Children's Hospital, Dr. Molewaterplein 60, Room SP-3464, 3015 GJ, Rotterdam, The Netherlands.,Department of Radiology, Erasmus Medical Center, Dr. Molewaterplein 60, Room SP-3464, 3015 GJ, Rotterdam, The Netherlands
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5
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Carinci F, Meyer C, Breuer FA, Jakob PM. In vivo imaging of the spectral line broadening of the human lung in a single breathhold. J Magn Reson Imaging 2016; 44:745-57. [DOI: 10.1002/jmri.25192] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 01/25/2016] [Indexed: 11/09/2022] Open
Affiliation(s)
- Flavio Carinci
- Research Center Magnetic Resonance Bavaria (MRB); Würzburg Germany
- Department of Experimental Physics 5; University of Würzburg; Würzburg Germany
- Siemens Healthcare Gmbh; Erlangen Germany
| | - Cord Meyer
- Department of Experimental Physics 5; University of Würzburg; Würzburg Germany
| | - Felix A. Breuer
- Research Center Magnetic Resonance Bavaria (MRB); Würzburg Germany
| | - Peter M. Jakob
- Research Center Magnetic Resonance Bavaria (MRB); Würzburg Germany
- Department of Experimental Physics 5; University of Würzburg; Würzburg Germany
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6
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Gai ND, Malayeri A, Agarwal H, Evers R, Bluemke D. Evaluation of optimized breath-hold and free-breathing 3D ultrashort echo time contrast agent-free MRI of the human lung. J Magn Reson Imaging 2015; 43:1230-8. [PMID: 26458867 DOI: 10.1002/jmri.25073] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 09/25/2015] [Indexed: 01/11/2023] Open
Abstract
PURPOSE To evaluate an optimized stack of radials ultrashort echo time (UTE) 3D magnetic resonance imaging (MRI) sequence for breath-hold and free-breathing imaging of the human lung. MATERIALS AND METHODS A 3D stack of ultrashort echo time radials trajectory was optimized for coronal and axial lower-resolution breath-hold and higher-resolution free-breathing scans using Bloch simulations. The sequence was evaluated in 10 volunteers, without the use of contrast agents. Signal-to-noise ratio (SNR) mean and 95% confidence interval (CI) were determined from separate signal and noise images in a semiautomated fashion. The four scanning schemes were evaluated for significant differences in image quality using Student's t-test. Ten clinical patients were scanned with the sequence and findings were compared with concomitant computed tomography (CT) in nine patients. Breath-hold 3D spokes images were compared with 3D stack of radials in five volunteers. A Mann-Whitney U-test was performed to test significance in both cases. RESULTS Breath-hold imaging of the entire lung in volunteers was performed with SNR (mean = 42.5 [CI]: 35.5-49.5; mean = 34.3 [CI]: 28.6-40) in lung parenchyma for coronal and axial scans, respectively, which can be used as a quick scout scan. Longer respiratory triggered free-breathing scan enabled high-resolution UTE scanning with mean SNR of 14.2 ([CI]: 12.9-15.5) and 9.2 ([CI]: 8.2-10.2) for coronal and axial scans, respectively. Axial free-breathing scans showed significantly higher image quality (P = 0.008) than the three other scanning schemes. The mean score for comparison with CT was 1.67 (score 0: n = 0; 1: n = 3; 2: n = 6). There was no significant difference between CT and MRI (P = 0.25). 3D stack of radials images were significantly better than 3D spokes images (P < 0.001). CONCLUSION The optimized 3D stack of radials trajectory was shown to provide high-quality MR images of the lung parenchyma without the use of MRI contrast agents. The sequence may offer the possibility of breath-hold imaging and provides greater flexibility in trading off slice thickness and parallel imaging for scan time.
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Affiliation(s)
- Neville D Gai
- Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Ashkan Malayeri
- Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Harsh Agarwal
- Philips Research N.A., Briarcliff Manor, New York, USA
| | - Robert Evers
- Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - David Bluemke
- Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
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7
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Mulkern R, Haker S, Mamata H, Lee E, Mitsouras D, Oshio K, Balasubramanian M, Hatabu H. Lung Parenchymal Signal Intensity in MRI: A Technical Review with Educational Aspirations Regarding Reversible Versus Irreversible Transverse Relaxation Effects in Common Pulse Sequences. CONCEPTS IN MAGNETIC RESONANCE. PART A, BRIDGING EDUCATION AND RESEARCH 2014; 43A:29-53. [PMID: 25228852 PMCID: PMC4163152 DOI: 10.1002/cmr.a.21297] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Lung parenchyma is challenging to image with proton MRI. The large air space results in ~l/5th as many signal-generating protons compared to other organs. Air/tissue magnetic susceptibility differences lead to strong magnetic field gradients throughout the lungs and to broad frequency distributions, much broader than within other organs. Such distributions have been the subject of experimental and theoretical analyses which may reveal aspects of lung microarchitecture useful for diagnosis. Their most immediate relevance to current imaging practice is to cause rapid signal decays, commonly discussed in terms of short T2* values of 1 ms or lower at typical imaging field strengths. Herein we provide a brief review of previous studies describing and interpreting proton lung spectra. We then link these broad frequency distributions to rapid signal decays, though not necessarily the exponential decays generally used to define T2* values. We examine how these decays influence observed signal intensities and spatial mapping features associated with the most prominent torso imaging sequences, including spoiled gradient and spin echo sequences. Effects of imperfect refocusing pulses on the multiple echo signal decays in single shot fast spin echo (SSFSE) sequences and effects of broad frequency distributions on balanced steady state free precession (bSSFP) sequence signal intensities are also provided. The theoretical analyses are based on the concept of explicitly separating the effects of reversible and irreversible transverse relaxation processes, thus providing a somewhat novel and more general framework from which to estimate lung signal intensity behavior in modern imaging practice.
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Affiliation(s)
| | - Steven Haker
- Brigham and Women's Hospital, Radiology, Boston, MA, 02115
| | - Hatsuho Mamata
- Brigham and Women's Hospital, Radiology, Boston, MA, 02115
| | - Edward Lee
- Children's Hospital, Radiology, Boston, MA, 02115
| | | | - Koichi Oshio
- Brigham and Women's Hospital, Radiology, Boston, MA, 02115
| | | | - Hiroto Hatabu
- Brigham and Women's Hospital, Radiology, Boston, MA, 02115
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Owrangi AM, Wang JX, Wheatley A, McCormack DG, Parraga G. Quantitative 1H and hyperpolarized 3He magnetic resonance imaging: Comparison in chronic obstructive pulmonary disease and healthy never-smokers. Eur J Radiol 2014; 83:64-72. [DOI: 10.1016/j.ejrad.2012.02.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Accepted: 02/27/2012] [Indexed: 10/28/2022]
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9
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Simon BA, Kaczka DW, Bankier AA, Parraga G. What can computed tomography and magnetic resonance imaging tell us about ventilation? J Appl Physiol (1985) 2012; 113:647-57. [PMID: 22653989 DOI: 10.1152/japplphysiol.00353.2012] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
This review provides a summary of pulmonary functional imaging approaches for determining pulmonary ventilation, with a specific focus on multi-detector x-ray computed tomography and magnetic resonance imaging (MRI). We provide the important functional definitions of pulmonary ventilation typically used in medicine and physiology and discuss the fact that some of the imaging literature describes gas distribution abnormalities in pulmonary disease that may or may not be related to the physiological definition or clinical interpretation of ventilation. We also review the current state-of-the-field in terms of the key physiological questions yet unanswered related to ventilation and gas distribution in lung disease. Current and emerging imaging research methods are described, including their strengths and the challenges that remain to translate these methods to more wide-spread research and clinical use. We also examine how computed tomography and MRI might be used in the future to gain more insight into gas distribution and ventilation abnormalities in pulmonary disease.
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Affiliation(s)
- Brett A Simon
- Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
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10
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Togao O, Ohno Y, Dimitrov I, Hsia CC, Takahashi M. Ventilation/perfusion imaging of the lung using ultra-short echo time (UTE) MRI in an animal model of pulmonary embolism. J Magn Reson Imaging 2011; 34:539-46. [PMID: 21761465 DOI: 10.1002/jmri.22645] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Accepted: 04/07/2011] [Indexed: 11/06/2022] Open
Abstract
PURPOSE To test the feasibility of ultra-short echo time (UTE) MRI for assessment of regional pulmonary ventilation/perfusion in a standard 3 Tesla clinical MRI system. MATERIALS AND METHODS MRI of the lungs was conducted with an optimized three-dimensional UTE sequence in normal rats and in a rat model of pulmonary embolism (PE) induced by a blood clot. Changes in signal intensities (SIs) due to inhalation of molecular oxygen or intravenous (i.v.) injection of Gd, which represents the distribution of ventilation and perfusion, respectively, were assessed in the lung parenchyma. RESULTS The UTE MRI with a TE of 100 μs could detect and map the changes in SI of the lung parenchyma due to the inhalation of 100% oxygen or i.v. injection of Gd in normal rats. Reduced T1 resulting from oxygen inhalation was also quantified. These changes were not observed on the images that were obtained simultaneously with a conventional range of TE (2.3 ms). Furthermore, the method could delineate the embolized lesions where the lung ventilation and perfusion were mismatched in a rat model with PE. CONCLUSION These results show the feasibility and diagnostic potential of UTE MRI for the assessment of pulmonary ventilation and perfusion which is essential for the evaluation of a variety of lung diseases.
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Affiliation(s)
- Osamu Togao
- UT Southwestern Medical Center, Dallas, Texas 75390-8542, USA
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11
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Mariappan YK, Glaser KJ, Hubmayr RD, Manduca A, Ehman RL, McGee KP. MR elastography of human lung parenchyma: technical development, theoretical modeling and in vivo validation. J Magn Reson Imaging 2011; 33:1351-61. [PMID: 21591003 PMCID: PMC3098473 DOI: 10.1002/jmri.22550] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
PURPOSE To develop a novel MR-based method for visualizing the elastic properties of human lung parenchyma in vivo and to evaluate the ability of this method to resolve differences in parenchymal stiffness at different respiration states in healthy volunteers. MATERIALS AND METHODS A spin-echo MR Elastography (MRE) pulse sequence was developed to provide both high shear wave motion sensitivity and short TE for improved visualization of lung parenchyma. The improved motion sensitivity of this approach was modeled and tested with phantom experiments. In vivo testing was then performed on 10 healthy volunteers at the respiratory states of residual volume (RV) and total lung capacity (TLC). RESULTS Shear wave propagation was visualized within the lungs of all volunteers and was processed to provide parenchymal shear stiffness maps for all 10 subjects. Density corrected stiffness values at TLC (1.83 ± 0.22 kPa) were higher than those at the RV (1.14 ± 0.14 kPa) with the difference being statistically significant (P < 0.0001). CONCLUSION (1)H-based MR elastography can noninvasively measure the shear stiffness of human lung parenchyma in vivo and can quantitate the change in shear stiffness due to respiration. The values obtained were consistent with previously reported in vitro assessments of cadaver lungs. Further work is required to increase the flexibility of the current acquisition and to investigate the clinical potential of lung MRE.
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Affiliation(s)
| | - Kevin J Glaser
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
| | - Rolf D Hubmayr
- Department of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN, USA
| | | | | | - Kiaran P McGee
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
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12
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Takahashi M, Togao O, Obara M, van Cauteren M, Ohno Y, Doi S, Kuro-o M, Malloy C, Hsia CC, Dimitrov I. Ultra-short echo time (UTE) MR imaging of the lung: comparison between normal and emphysematous lungs in mutant mice. J Magn Reson Imaging 2010; 32:326-33. [PMID: 20677258 DOI: 10.1002/jmri.22267] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
PURPOSE To investigate the utility of ultra-short echo time (UTE) sequence as pulmonary MRI to detect non-uniform disruption of lung architecture that is typical of emphysema. MATERIALS AND METHODS MRI of the lungs was conducted with a three-dimensional UTE sequence in transgenic mice with severe emphysema and their wild-type littermates in a 3 Tesla clinical MR system. Measurements of the signal intensity (SI) and transverse relaxation time (T2*) of the lung parenchyma were performed with various echo times (TEs) ranging from 100 micros to 2 ms. RESULTS Much higher SI of the lung parenchyma was observed at an UTE of 100 micros compared with longer TEs. The emphysematous lungs had reduced SIs and T2* than the controls, in particular at end-expiratory phase. The results suggested that both SI and T2* in lung parenchyma measured with the method represent fractional volume of lung tissue. CONCLUSION The UTE imaging provided MR signal from the lung parenchyma. Moreover, the UTE sequence was sensitive to emphysematous changes and may provide a direct assessment of lung parenchyma. UTE imaging has the potential to assist detection of localized pathological destruction of lung tissue architecture in emphysema.
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Affiliation(s)
- Masaya Takahashi
- Advanced Imaging Research Center, UT Southwestern Medical Center, 2201 Inwood Rd, Dallas, Texas 75390-8542, USA.
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13
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Togao O, Tsuji R, Ohno Y, Dimitrov I, Takahashi M. Ultrashort echo time (UTE) MRI of the lung: Assessment of tissue density in the lung parenchyma. Magn Reson Med 2010; 64:1491-8. [DOI: 10.1002/mrm.22521] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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14
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Iwasawa T, Takahashi H, Ogura T, Asakura A, Gotoh T, Kagei S, Nishimura JI, Obara M, Inoue T. Correlation of lung parenchymal MR signal intensity with pulmonary function tests and quantitative computed tomography (CT) evaluation: a pilot study. J Magn Reson Imaging 2008; 26:1530-6. [PMID: 17968893 DOI: 10.1002/jmri.21183] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
PURPOSE To evaluate the effect of ventilatory impairment on MR signal intensity of the lung parenchyma. MATERIALS AND METHODS Subjects were five normal volunteers (age = 30 +/- 7.9 years, mean +/- SD) and 19 male patients with chronic obstructive lung disease (COPD) (mean age = 70.4 +/- 6.5 years). Coronal MR images were obtained over entire lung fields at full inspiration and full expiration with cardiac triggering on a 1.5T system. Changes in the mean lung intensity between the two respiratory states were normalized by each intercept of the linear regression lines of the signal changes, and the slope of the relationship was calculated. Computed tomography (CT) images were also obtained in COPD patients at full inspiration using a multidetector row CT scanner. Attenuation values less than -950 Hounsfield units (HU) (RA-950) represented the percentage of relative lung area on the CT. RESULTS The mean slope of COPD patients (0.365 +/- 0.074) was less steep than that of the normal subjects (0.570 +/- 0.124, P < 0.001). In COPD patients, the slope correlated significantly with forced expiratory volume in one second (FEV1, r = 0.508, P = 0.026), but not with RA-950. CONCLUSION In COPD patients, lung signal change measured by MRI correlates with airflow obstruction, but not with volume of the emphysema measured by lung CT.
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Affiliation(s)
- Tae Iwasawa
- Department of Radiology, Kanagawa Cardiovascular and Respiratory Center, Yokohama, Japan.
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Nichols MB, Paschal CB. Measurement of longitudinal (T1) relaxation in the human lung at 3.0 Tesla with tissue-based and regional gradient analyses. J Magn Reson Imaging 2007; 27:224-8. [DOI: 10.1002/jmri.21243] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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