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Panda A, Francois CJ, Bookwalter CA, Chaturvedi A, Collins JD, Leiner T, Rajiah PS. Non-Contrast Magnetic Resonance Angiography: Techniques, Principles, and Applications. Magn Reson Imaging Clin N Am 2023; 31:337-360. [PMID: 37414465 DOI: 10.1016/j.mric.2023.04.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/08/2023]
Abstract
Several non-contrast magnetic resonance angiography (MRA) techniques have been developed, providing an attractive alternative to contrast-enhanced MRA and a radiation-free alternative to computed tomography (CT) CT angiography. This review describes the physical principles, limitations, and clinical applications of bright-blood (BB) non-contrast MRA techniques. The principles of BB MRA techniques can be broadly divided into (a) flow-independent MRA, (b) blood-inflow-based MRA, (c) cardiac phase dependent, flow-based MRA, (d) velocity sensitive MRA, and (e) arterial spin-labeling MRA. The review also includes emerging multi-contrast MRA techniques that provide simultaneous BB and black-blood images for combined luminal and vessel wall evaluation.
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Affiliation(s)
- Ananya Panda
- Department of Radiology, All India Institute of Medical Sciences, Jodhpur, India
| | | | | | - Abhishek Chaturvedi
- Department of Radiology, University of Rochester Medical Center, Rochester, NY, USA
| | | | - Tim Leiner
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
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Tanaka Y, Ohno Y, Hanamatsu S, Obama Y, Ueda T, Ikeda H, Iwase A, Fukuba T, Hattori H, Murayama K, Yoshikawa T, Takenaka D, Koyama H, Toyama H. State-of-the-art MR Imaging for Thoracic Diseases. Magn Reson Med Sci 2021; 21:212-234. [PMID: 33952785 PMCID: PMC9199970 DOI: 10.2463/mrms.rev.2020-0184] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Since thoracic MR imaging was first used in a clinical setting, it has been suggested that MR imaging has limited clinical utility for thoracic diseases, especially lung diseases, in comparison with x-ray CT and positron emission tomography (PET)/CT. However, in many countries and states and for specific indications, MR imaging has recently become practicable. In addition, recently developed pulmonary MR imaging with ultra-short TE (UTE) and zero TE (ZTE) has enhanced the utility of MR imaging for thoracic diseases in routine clinical practice. Furthermore, MR imaging has been introduced as being capable of assessing pulmonary function. It should be borne in mind, however, that these applications have so far been academically and clinically used only for healthy volunteers, but not for patients with various pulmonary diseases in Japan or other countries. In 2020, the Fleischner Society published a new report, which provides consensus expert opinions regarding appropriate clinical indications of pulmonary MR imaging for not only oncologic but also pulmonary diseases. This review article presents a brief history of MR imaging for thoracic diseases regarding its technical aspects and major clinical indications in Japan 1) in terms of what is currently available, 2) promising but requiring further validation or evaluation, and 3) developments warranting research investigations in preclinical or patient studies. State-of-the-art MR imaging can non-invasively visualize lung structural and functional abnormalities without ionizing radiation and thus provide an alternative to CT. MR imaging is considered as a tool for providing unique information. Moreover, prospective, randomized, and multi-center trials should be conducted to directly compare MR imaging with conventional methods to determine whether the former has equal or superior clinical relevance. The results of these trials together with continued improvements are expected to update or modify recommendations for the use of MRI in near future.
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Affiliation(s)
- Yumi Tanaka
- Department of Radiology, Fujita Health University School of Medicine
| | - Yoshiharu Ohno
- Department of Radiology, Fujita Health University School of Medicine.,Joint Research Laboratory of Advanced Medical Imaging, Fujita Health University School of Medicine
| | - Satomu Hanamatsu
- Department of Radiology, Fujita Health University School of Medicine
| | - Yuki Obama
- Department of Radiology, Fujita Health University School of Medicine
| | - Takahiro Ueda
- Department of Radiology, Fujita Health University School of Medicine
| | - Hirotaka Ikeda
- Department of Radiology, Fujita Health University School of Medicine
| | - Akiyoshi Iwase
- Department of Radiology, Fujita Health University Hospital
| | - Takashi Fukuba
- Department of Radiology, Fujita Health University Hospital
| | - Hidekazu Hattori
- Department of Radiology, Fujita Health University School of Medicine
| | - Kazuhiro Murayama
- Joint Research Laboratory of Advanced Medical Imaging, Fujita Health University School of Medicine
| | | | | | | | - Hiroshi Toyama
- Department of Radiology, Fujita Health University School of Medicine
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Ohno Y, Hanamatsu S, Obama Y, Ueda T, Ikeda H, Hattori H, Murayama K, Toyama H. Overview of MRI for pulmonary functional imaging. Br J Radiol 2021; 95:20201053. [PMID: 33529053 DOI: 10.1259/bjr.20201053] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Morphological evaluation of the lung is important in the clinical evaluation of pulmonary diseases. However, the disease process, especially in its early phases, may primarily result in changes in pulmonary function without changing the pulmonary structure. In such cases, the traditional imaging approaches to pulmonary morphology may not provide sufficient insight into the underlying pathophysiology. Pulmonary imaging community has therefore tried to assess pulmonary diseases and functions utilizing not only nuclear medicine, but also CT and MR imaging with various technical approaches. In this review, we overview state-of-the art MR methods and the future direction of: (1) ventilation imaging, (2) perfusion imaging and (3) biomechanical evaluation for pulmonary functional imaging.
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Affiliation(s)
- Yoshiharu Ohno
- Department of Radiology, Fujita Health University, School of Medicine, Toyoake, Japan.,Joint Research Laboratory of Advanced Medical Imaging, Fujita Health University School of Medicine, Toyoake, Japan
| | - Satomu Hanamatsu
- Department of Radiology, Fujita Health University, School of Medicine, Toyoake, Japan
| | - Yuki Obama
- Department of Radiology, Fujita Health University, School of Medicine, Toyoake, Japan
| | - Takahiro Ueda
- Department of Radiology, Fujita Health University, School of Medicine, Toyoake, Japan
| | - Hirotaka Ikeda
- Department of Radiology, Fujita Health University, School of Medicine, Toyoake, Japan
| | - Hidekazu Hattori
- Department of Radiology, Fujita Health University, School of Medicine, Toyoake, Japan
| | - Kazuhiro Murayama
- Joint Research Laboratory of Advanced Medical Imaging, Fujita Health University School of Medicine, Toyoake, Japan
| | - Hiroshi Toyama
- Department of Radiology, Fujita Health University, School of Medicine, Toyoake, Japan
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Abstract
BACKGROUND One disadvantage of magnetic resonance imaging (MRI) is the inability to adequately image the lungs. Recent advances in hyperpolarized gas technology [e.g., helium-3 ((3)He) and xenon-129 ((129)Xe)] have changed this. However, the required technology is expensive and often needing extra physics or engineering staff. Hence there is considerable interest in developing (1)H (proton)-based MRI approaches that can be readily implemented on standard clinical systems. Thus, the purpose of this work was to compare a newly developed free breathing proton-based MR lung imaging method to that of a standard gadolinium (Gd) based perfusion approach. METHODS Healthy volunteers [10] were scanned using a 3-T MRI with 8 parallel receivers, and a cardiac gated fast spin echo (FSE) sequence. Acquisition was cardiac triggered, with different time delays incremented to cover the entire cardiac cycle. Image k-space was filled rectilinearly. But to reduce motion artefacts k-space was retrospectively sorted using the minimal variance algorithm (MVA), based on physiologic data recorded from both the respiratory bellows and electrocardiogram (ECG). Resorted and reconstructed FSE images were compared to contrast enhanced lung images, obtained following intravenous injection of Gd-DTPA-BMA. RESULTS Biphasic variation in FSE lung signal intensity was observed across the cardiac cycle with a maximal signal change following rapid cardiac ejection (between S and T waves), and following rapid isovolumetric relaxation. A difference image between systolic and diastolic states in the cardiac cycle resulted in images with improved lung contrast to noise ratio (CNR). FSE image intensity was uniform over lung parenchyma while Gd-based enhancement of spoiled gradient recalled echo (SPGR) images showed gravitational dependence. CONCLUSIONS Here we show how 1H-MR images of lung can be obtained during free breathing. The image contrast obtained during this approach is likely the result of flow and oxygen modulation during the cardiac cycle. This free breathing method provides lung images comparable to those obtained using Gd-enhancement. Besides having the advantage of free breathing, this approach doesn't require any Gd-contrast or suffer from methodological problems associated with perfusion (e.g., poor bolus timing). However, as gravitational differences typically observed in lung perfusion are not visible with this method it is not providing exclusive microvascular perfusion information.
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Affiliation(s)
- Sergei I Obruchkov
- 1 Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario, Canada ; 2 Imaging Research Centre, St. Joseph's Healthcare, Hamilton, Ontario, Canada ; 3 Department of Electrical and Computer Engineering, 4 McMaster School of Biomedical Engineering, 5 Department of Radiology, McMaster University, Hamilton, Ontario, Canada
| | - Michael D Noseworthy
- 1 Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario, Canada ; 2 Imaging Research Centre, St. Joseph's Healthcare, Hamilton, Ontario, Canada ; 3 Department of Electrical and Computer Engineering, 4 McMaster School of Biomedical Engineering, 5 Department of Radiology, McMaster University, Hamilton, Ontario, Canada
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Zhang WJ, Hubbard Cristinacce PL, Bondesson E, Nordenmark LH, Young SS, Liu YZ, Singh D, Naish JH, Parker GJM. MR Quantitative Equilibrium Signal Mapping: A Reliable Alternative to CT in the Assessment of Emphysema in Patients with Chronic Obstructive Pulmonary Disease. Radiology 2015; 275:579-88. [DOI: 10.1148/radiol.14132953] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Ohno Y, Seki S, Koyama H, Yoshikawa T, Matsumoto S, Takenaka D, Kassai Y, Yui M, Sugimura K. 3D ECG- and respiratory-gated non-contrast-enhanced (CE) perfusion MRI for postoperative lung function prediction in non-small-cell lung cancer patients: A comparison with thin-section quantitative computed tomography, dynamic CE-perfusion MRI, and perfus. J Magn Reson Imaging 2014; 42:340-53. [DOI: 10.1002/jmri.24800] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2014] [Accepted: 10/24/2014] [Indexed: 12/25/2022] Open
Affiliation(s)
- Yoshiharu Ohno
- Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine; Kobe Japan
- Division of Functional and Diagnostic Imaging Research, Department of Radiology; Kobe University Graduate School of Medicine; Kobe Japan
| | - Shinichiro Seki
- Division of Radiology, Department of Radiology; Kobe University Graduate School of Medicine; Kobe Japan
| | - Hisanobu Koyama
- Division of Radiology, Department of Radiology; Kobe University Graduate School of Medicine; Kobe Japan
| | - Takeshi Yoshikawa
- Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine; Kobe Japan
- Division of Functional and Diagnostic Imaging Research, Department of Radiology; Kobe University Graduate School of Medicine; Kobe Japan
| | - Sumiaki Matsumoto
- Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine; Kobe Japan
- Division of Functional and Diagnostic Imaging Research, Department of Radiology; Kobe University Graduate School of Medicine; Kobe Japan
| | - Daisuke Takenaka
- Division of Radiology, Department of Radiology; Kobe University Graduate School of Medicine; Kobe Japan
- Department of Radiology; Hyogo Cancer Center; Akashi Japan
| | | | - Masao Yui
- Toshiba Medical Systems Corporation; Otawara Japan
| | - Kazuro Sugimura
- Division of Radiology, Department of Radiology; Kobe University Graduate School of Medicine; Kobe Japan
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Hamedani H, Kadlecek SJ, Ishii M, Xin Y, Emami K, Han B, Shaghaghi H, Gopstein D, Cereda M, Gefter WB, Rossman MD, Rizi RR. Alterations of regional alveolar oxygen tension in asymptomatic current smokers: assessment with hyperpolarized (3)He MR imaging. Radiology 2014; 274:585-96. [PMID: 25322340 DOI: 10.1148/radiol.14132809] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To assess the ability of helium 3 ((3)He) magnetic resonance (MR) imaging of regional alveolar partial pressure of oxygen (Pao2) to depict smoking-induced functional alterations and to compare its efficacy to that of current diagnostic techniques. MATERIALS AND METHODS This study was approved by the local institutional review board and was compliant with HIPAA. All subjects provided informed consent. A total of 43 subjects were separated into three groups: nonsmokers, asymptomatic smokers, and symptomatic smokers. All subjects underwent a Pao2 imaging session followed by clinically standard pulmonary function tests (PFTs), the 6-minute walk test, and St George Respiratory Questionnaire (SGRQ). The whole-lung mean and standard deviation of Pao2 were compared with metrics derived from PFTs, the 6-minute walk test, and the SGRQ. A logistic regression model was developed to identify the predictors of alterations to the lungs of asymptomatic smokers. RESULTS The whole-lung standard deviation of Pao2 correlated with PFT metrics (forced expiratory volume in 1 second [FEV1]/forced vital capacity [FVC], Pearson r = -0.69, P < .001; percentage predicted FEV1, Pearson r = -0.67, P < .001; diffusing capacity of lung for carbon monoxide [Dlco], Pearson r = -0.45, P = .003), SGRQ score (Pearson r = 0.67, P < .001), and distance walked in 6 minutes (Pearson r = -0.47, P = .002). The standard deviation of Pao2 was significantly higher in asymptomatic smokers than in nonsmokers (change in the standard deviation of Pao2 = 7.59 mm Hg, P = .041) and lower when compared with symptomatic smokers (change in the standard deviation of Pao2 = 10.72 mm Hg, P = .001). A multivariate prediction model containing FEV1/FVC and the standard deviation of Pao2 (as significant predictors of subclinical changes in smokers) and Dlco (as a confounding variable) was formulated. This model resulted in an area under the receiver operating characteristic curve with a significant increase of 29.2% when compared with a prediction model based solely on nonimaging clinical tests. CONCLUSION The (3)He MR imaging heterogeneity metric (standard deviation of Pao2) enabled the differentiation of all three study cohorts, which indicates that it can depict smoking-related functional alterations in asymptomatic current smokers.
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Affiliation(s)
- Hooman Hamedani
- From the Department of Radiology (H.H., S.J.K., M.I., Y.X., K.E., B.H., H.S., D.G., W.G., R.R.R.), Department of Anesthesiology and Critical Care (M.C.), and Pulmonary, Allergy and Critical Care Division (M.D.R.), University of Pennsylvania, 308 Stemmler Hall, 3450 Hamilton Walk, Philadelphia, PA 19104
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François CJ, Hartung MP, Reeder SB, Nagle SK, Schiebler ML. MRI for acute chest pain: current state of the art. J Magn Reson Imaging 2013; 37:1290-300. [PMID: 23589367 DOI: 10.1002/jmri.24173] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 03/20/2013] [Indexed: 01/08/2023] Open
Abstract
This article reviews the magnetic resonance imaging (MRI) and angiography (MRA) techniques, imaging findings, and evidence for evaluating patients with acute chest pain due to acute pulmonary embolus (PE), aortic dissection (AD), and myocardial infarction (MI). When computed tomographic angiography (CTA) is contraindicated, MRI and MRA are important alternative imaging modalities for diagnosis and management of patients with acute PE, AD, and MI. Familiarity with the techniques, imaging findings, and evidence is critical to safely and appropriately managing patients presenting with acute chest pain.
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Affiliation(s)
- Christopher J François
- Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin 53792-3252, USA.
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Abstract
Pulmonary emphysema is a pathologic condition characterized by permanently enlarged airspaces distal to the terminal bronchiole with destruction of the alveolar walls. Functional information of the lungs is important to understand the pathophysiology of emphysema and that of chronic obstructive pulmonary disease. With the recent developments in magnetic resonance imaging (MRI) techniques, functional MRI with variable MR sequences can be used for the evaluation of different physiological and anatomic changes seen in cases of pulmonary emphysema. In this review article, we will focus on a brief description of each method, results of some of the most recent work, and the clinical application of such knowledge.
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Fan L, Xia Y, Guan Y, Yu H, Zhang TF, Liu SY, Li B. Capability of differentiating smokers with normal pulmonary function from COPD patients: a comparison of CT pulmonary volume analysis and MR perfusion imaging. Eur Radiol 2012; 23:1234-41. [DOI: 10.1007/s00330-012-2729-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2012] [Revised: 10/18/2012] [Accepted: 10/28/2012] [Indexed: 10/27/2022]
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Okajima Y, Ohno Y, Washko GR, Hatabu H. Assessment of pulmonary hypertension what CT and MRI can provide. Acad Radiol 2011; 18:437-53. [PMID: 21377593 DOI: 10.1016/j.acra.2011.01.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Revised: 01/06/2011] [Accepted: 01/12/2011] [Indexed: 01/06/2023]
Abstract
RATIONALES AND OBJECTIVES Pulmonary hypertension (PH) is a life-threatening condition, characterized by elevated pulmonary arterial pressure, which is confirmed based on invasive right heart catheterization (RHC). Noninvasive examinations may support diagnosis of PH before proceeding to RHC and play an important role in management and treatment of the disease. Although echocardiography is considered a standard tool in diagnosis, recent advances have made computed tomography (CT) and magnetic resonance (MR) imaging promising tools, which may provide morphologic and functional information. In this article, we review image-based assessment of PH with a focus on CT and MR imaging. CONCLUSIONS CT may provide useful morphologic information for depicting PH and seeking for underlying diseases. With the accumulated technological advancement, CT and MRI may provide practical tools for not only morphologic but also functional assessment of patients with PH.
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Affiliation(s)
- Yuka Okajima
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
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Vidal Melo MF, Winkler T, Harris RS, Musch G, Greene RE, Venegas JG. Spatial heterogeneity of lung perfusion assessed with (13)N PET as a vascular biomarker in chronic obstructive pulmonary disease. J Nucl Med 2009; 51:57-65. [PMID: 20008987 DOI: 10.2967/jnumed.109.065185] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED Although it is known that structural and functional changes in the pulmonary vasculature and parenchyma occur in the progress of chronic obstructive pulmonary disease (COPD), information is limited on early regional perfusion (Q(r)) alterations. METHODS We studied 6 patients with mild or moderate COPD and 9 healthy subjects (6 young and 3 age-matched). The PET (13)NN-labeled saline injection method was used to compute images of Q(r) and regional ventilation (V(r)). Transmission scans were used to assess regional density. We used the squared coefficient of variation to quantify Q(r) heterogeneity and length-scale analysis to quantify the contribution to total perfusion heterogeneity of regions ranging from less than 12 to more than 108 mm. RESULTS Perfusion distribution in COPD subjects showed larger Q(r) heterogeneity, higher contribution from large length scales and lower contribution from small length scales, and larger heterogeneity of Q(r) normalized by tissue density than did healthy subjects. Dorsoventral gradients of V(r) were present in healthy subjects, with larger ventilation in dependent regions, whereas no gradient was present in COPD. Heterogeneity of ventilation-perfusion ratios was larger in COPD. CONCLUSION Q(r) is significantly redistributed in COPD. Q(r) heterogeneity in COPD patients is greater than in healthy subjects, mainly because of the contribution of large lung regions and not because of changes in tissue density or V(r). The assessment of spatial heterogeneity of lung perfusion with (13)NN-saline PET may serve as a vascular biomarker in COPD.
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Affiliation(s)
- Marcos F Vidal Melo
- Department of Anesthesia and Critical Care, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA.
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Abstract
This article discusses the role of magnetic resonance angiography (MRA) in evaluating the pulmonary arterial system. For depiction of pulmonary arterial anatomy and morphology, MRA techniques are compared with CT angiography and digital subtraction x-ray angiography. Perfusion, flow, and function are emphasized, as the integrated MR examination offers a comprehensive assessment of vascular morphology and function. Advances in MR technology that improve spatial and temporal resolution and compensate for potential artifacts are reviewed as they pertain to pulmonary MRA. Current and emerging gadolinium contrast-enhanced and non-contrast-enhanced MRA techniques are discussed. The role of pulmonary MRA, clinical protocols, imaging findings, and interpretation pitfalls are reviewed for clinical indications.
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Affiliation(s)
- Elizabeth M Hecht
- Department of Radiology, New York University School of Medicine, 560 First Avenue, TCH-HW202, New York, NY 10016, USA.
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Quantitatively Assessed Dynamic Contrast-Enhanced Magnetic Resonance Imaging in Patients With Chronic Obstructive Pulmonary Disease: Correlation of Perfusion Parameters With Pulmonary Function Test and Quantitative Computed Tomography. Invest Radiol 2008; 43:403-10. [DOI: 10.1097/rli.0b013e31816901ab] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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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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Ohno Y, Iwasawa T, Seo JB, Koyama H, Takahashi H, Oh YM, Nishimura Y, Sugimura K. Oxygen-enhanced magnetic resonance imaging versus computed tomography: multicenter study for clinical stage classification of smoking-related chronic obstructive pulmonary disease. Am J Respir Crit Care Med 2008; 177:1095-102. [PMID: 18276941 DOI: 10.1164/rccm.200709-1322oc] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Oxygen-enhanced magnetic resonance imaging (MRI) has been proposed as a useful tool for assessing regional morphological and functional changes in chronic obstructive pulmonary disease (COPD). OBJECTIVES To prospectively and directly compare the efficacy of O(2)-enhanced MRI and quantitative computed tomography (CT) for smoking-related pulmonary functional loss assessment and clinical stage classification of smoking-related COPD. METHODS One hundred sixty smokers were classified into four age- and gender-matched groups by using the GOLD criteria for smokers: Smokers without COPD (n = 40), Mild COPD (n = 40), Moderate COPD (n = 40), and Severe or Very Severe COPD (n = 40). All smokers underwent O(2)-enhanced MRI, multidetector-row CT, and pulmonary function test. Mean relative enhancement ratio on O(2)-enhanced MRI and CT-based functional lung volume (FLV) on quantitative CT were calculated. To compare the efficacy of O(2)-enhanced MRI and quantitative CT for pulmonary functional loss assessment, both indexes were correlated with pulmonary functional parameters. To determine the efficacy of two methods for clinical stage classification, the four clinical groups' mean relative enhancement ratio and CT-based FLV were statistically compared. MEASUREMENTS AND MAIN RESULTS Correlations of both indexes with pulmonary functional parameters were significant (P < 0.0001). Pulmonary functional parameters and mean relative enhancement ratio for the four clinical groups showed significant differences (P < 0.05). CT-based FLVs of smokers without COPD and mild COPD were significantly different from those for moderate COPD and severe or very severe COPD (P < 0.05). CONCLUSIONS O(2)-enhanced MRI is effective for pulmonary functional loss assessment and clinical stage classification of smoking-related COPD and quantitative CT.
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Affiliation(s)
- Yoshiharu Ohno
- Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017, Japan.
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