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Sun A, Zhao B, Zheng Y, Long Y, Wu P, Wang B, Li R, Wang H. Motion-resolved real-time 4D flow MRI with low-rank and subspace modeling. Magn Reson Med 2023; 89:1839-1852. [PMID: 36533875 DOI: 10.1002/mrm.29557] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 11/01/2022] [Accepted: 11/25/2022] [Indexed: 12/23/2022]
Abstract
PURPOSE To develop a new motion-resolved real-time four-dimensional (4D) flow MRI method, which enables the quantification and visualization of blood flow velocities with three-directional flow encodings and volumetric coverage without electrocardiogram (ECG) synchronization and respiration control. METHODS An integrated imaging method is presented for real-time 4D flow MRI, which encompasses data acquisition, image reconstruction, and postprocessing. The proposed method features a specialized continuous ( k , t ) $$ \left(\mathbf{k},t\right) $$ -space acquisition scheme, which collects two sets of data (i.e., training data and imaging data) in an interleaved manner. By exploiting strong spatiotemporal correlation of 4D flow data, it reconstructs time-series images from highly-undersampled ( k , t ) $$ \left(\mathbf{k},t\right) $$ -space measurements with a low-rank and subspace model. Through data-binning-based postprocessing, it constructs a five-dimensional dataset (i.e., x-y-z-cardiac-respiratory), from which respiration-dependent flow information is further analyzed. The proposed method was evaluated in aortic flow imaging experiments with ten healthy subjects and two patients with atrial fibrillation. RESULTS The proposed method achieves 2.4 mm isotropic spatial resolution and 34.4 ms temporal resolution for measuring the blood flow of the aorta. For the healthy subjects, it provides flow measurements in good agreement with those from the conventional 4D flow MRI technique. For the patients with atrial fibrillation, it is able to resolve beat-by-beat pathological flow variations, which cannot be obtained from the conventional technique. The postprocessing further provides respiration-dependent flow information. CONCLUSION The proposed method enables high-resolution motion-resolved real-time 4D flow imaging without ECG gating and respiration control. It is able to resolve beat-by-beat blood flow variations as well as respiration-dependent flow information.
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Affiliation(s)
- Aiqi Sun
- Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai, China
| | - Bo Zhao
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas, USA.,Oden Institute for Computational Engineering and Sciences, University of Texas at Austin, Austin, Texas, USA
| | | | - Yuliang Long
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Peng Wu
- Philips Healthcare, Shanghai, China
| | - Bei Wang
- Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai, China
| | - Rui Li
- Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China
| | - He Wang
- Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai, China.,Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai, China
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2
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Moussavi A, Mißbach S, Serrano Ferrel C, Ghasemipour H, Kötz K, Drummer C, Behr R, Zimmermann WH, Boretius S. Comparison of cine and real-time cardiac MRI in rhesus macaques. Sci Rep 2021; 11:10713. [PMID: 34021218 PMCID: PMC8140156 DOI: 10.1038/s41598-021-90106-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 05/04/2021] [Indexed: 01/14/2023] Open
Abstract
Cardiac MRI in rhesus macaques, a species of major relevance for preclinical studies on biological therapies, requires artificial ventilation to realize breath holding. To overcome this limitation of standard cine MRI, the feasibility of Real-Time (RT) cardiac MRI has been tested in a cohort of ten adult rhesus macaques using a clinical MR-system. In spite of lower tissue contrast and sharpness of RT-MRI, cardiac functions were similarly well assessed by RT-MRI compared to cine MRI (similar intra-subject repeatability). However, systematic underestimation of the end-diastolic volume (31 ± 9%), end-systolic volume (20 ± 11%), stroke volume (40 ± 12%) and ejection fraction (13 ± 9%) hamper the comparability of RT-MRI results with those of other cardiac MRI methods. Yet, the underestimations were very consistent (< 5% variability) for repetitive measurements, making RT-MRI an appropriate alternative to cine MRI for longitudinal studies. In addition, RT-MRI enabled the analysis of cardio-respiratory coupling. All functional parameters showed lower values during expiration compared to inspiration, most likely due to the pressure-controlled artificial ventilation. In conclusion, despite systematic underestimation of the functional parameters, RT-MRI allowed the assessment of left ventricular function in macaques with significantly less experimental effort, measurement time, risk and burden for the animals compared to cine MRI.
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Affiliation(s)
- Amir Moussavi
- Functional Imaging Laboratory, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany. .,DZHK (German Center for Cardiovascular Research), Partner Site, Göttingen, Germany.
| | - Sophie Mißbach
- DZHK (German Center for Cardiovascular Research), Partner Site, Göttingen, Germany.,Platform Degenerative Diseases, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
| | - Claudia Serrano Ferrel
- Functional Imaging Laboratory, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany.,Institute of Pharmacology and Toxicology, University Medical Center, Göttingen, Germany
| | - Hasti Ghasemipour
- Functional Imaging Laboratory, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
| | - Kristin Kötz
- Functional Imaging Laboratory, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
| | - Charis Drummer
- DZHK (German Center for Cardiovascular Research), Partner Site, Göttingen, Germany.,Platform Degenerative Diseases, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
| | - Rüdiger Behr
- DZHK (German Center for Cardiovascular Research), Partner Site, Göttingen, Germany.,Platform Degenerative Diseases, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
| | - Wolfram-Hubertus Zimmermann
- DZHK (German Center for Cardiovascular Research), Partner Site, Göttingen, Germany.,Institute of Pharmacology and Toxicology, University Medical Center, Göttingen, Germany
| | - Susann Boretius
- Functional Imaging Laboratory, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany.,DZHK (German Center for Cardiovascular Research), Partner Site, Göttingen, Germany.,Johann-Friedrich-Blumenbach Institute for Zoology and Anthropology, University of Göttingen, Göttingen, Germany
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Bertelsen L, Vejlstrup N, Andreasen L, Olesen MS, Svendsen JH. Cardiac magnetic resonance systematically overestimates mitral regurgitations by the indirect method. Open Heart 2020; 7:openhrt-2020-001323. [PMID: 32675299 PMCID: PMC7368492 DOI: 10.1136/openhrt-2020-001323] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 06/03/2020] [Accepted: 06/09/2020] [Indexed: 12/12/2022] Open
Abstract
Objective Cardiac MRI is quickly emerging as the gold standard for assessment of mitral regurgitation, most commonly with the indirect method subtracting forward flow in aorta from volumetric segmentation of the left ventricle. We aimed to investigate how aortic flow measurements with increasing distance from the aortic valve affect calculated mitral regurgitations and whether measurements were influenced by breath-hold regimen. Methods Free-breathing and breath-hold phase contrast flows were measured in aorta at valve level, sinotubular (ST) junction, mid-ascending aorta and in the pulmonary trunk. Flow measurements were pairwise compared, and subsequently, after exclusion of patients with visible mitral and tricuspid regurgitations for left-sided and right-sided comparisons, respectively, flow-measured stroke volumes were compared with ventricular volumetric segmentations. Results Thirty-nine participants without arrhythmias or structural abnormalities of the large vessels were included. Stroke volumes measured with free-breathing and breath-hold flow decreased equally with increasing distance to the aortic valves (breath-hold flow: aortic valve 105.6±20.8 mL, ST junction 101.5±20.7 mL, mid-ascending aorta 98.1±21.5 mL). After exclusion of atrioventricular regurgitations, stroke volumes determined by volumetric measurements were higher compared with values determined by flow measurements, corresponding to ‘false’ atrioventricular regurgitations of 8.0%±5.8% with flow measured at valve level, 11.6%±5.2% at the ST junction and 15.3%±5.0% at the mid-ascending aorta. Conclusions Stroke volumes determined by flow decrease throughout the proximal aorta and are systematically lower than volumetrically measured stroke volumes. The indirect method systematically overestimates mitral regurgitations, especially with increasing distance from the aortic valves.
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Affiliation(s)
- Litten Bertelsen
- Department of Cardiology, Centre for Cardiac, Vascular, Pulmonary and Infectious Diseases, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Niels Vejlstrup
- Department of Cardiology, Centre for Cardiac, Vascular, Pulmonary and Infectious Diseases, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Laura Andreasen
- Department of Cardiology, Centre for Cardiac, Vascular, Pulmonary and Infectious Diseases, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.,Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Morten Salling Olesen
- Department of Cardiology, Centre for Cardiac, Vascular, Pulmonary and Infectious Diseases, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.,Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jesper Hastrup Svendsen
- Department of Cardiology, Centre for Cardiac, Vascular, Pulmonary and Infectious Diseases, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.,Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
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Murillo H, Restrepo CS, Marmol-Velez JA, Vargas D, Ocazionez D, Martinez-Jimenez S, Reddick RL, Baxi AJ. Infectious Diseases of the Heart: Pathophysiology, Clinical and Imaging Overview. Radiographics 2017; 36:963-83. [PMID: 27399236 DOI: 10.1148/rg.2016150225] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Myriad infectious organisms can infect the endocardium, myocardium, and pericardium, including bacteria, fungi, parasites, and viruses. Significant cardiac infections are rare in the general population but are associated with high morbidity and mortality as well as increased risk in certain populations, such as the elderly, those undergoing cardiac instrumentation, and intravenous drug abusers. Diagnostic imaging of cardiac infections plays an important role despite its variable sensitivity and specificity, which are due in part to the nonspecific manifestations of the central inflammatory process of infection and the time of onset with respect to the time of imaging. The primary imaging modality remains echocardiography. However, cardiac computed tomography and magnetic resonance (MR) imaging have emerged as the modalities of choice wherever available, especially for diagnosis of complex infectious complications including abscesses, infected prosthetic material, central lines and instruments, and the cryptic manifestations of viral and parasitic diseases. MR imaging can provide functional, morphologic, and prognostic value in a single examination by allowing characterization of inflammatory changes from the acute to chronic stages, including edema and the patterns and extent of delayed gadolinium enhancement. We review the heterogeneous and diverse group of cardiac infections based on their site of primary cardiac involvement with emphasis on their cross-sectional imaging manifestations. Online supplemental material is available for this article. (©)RSNA, 2016.
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Affiliation(s)
- Horacio Murillo
- From the Division of Medical Imaging, Sutter Medical Group, 1500 Expo Pkwy, Sacramento, CA 95815 (H.M.); Department of Radiology (C.S.R., A.J.B.), Division of Cardiology (J.A.M.), and Department of Pathology (R.L.R.), University of Texas Health Science Center at San Antonio, San Antonio, Tex; Department of Radiology, University of Colorado Anschutz Medical Center, Aurora, Colo (D.V.); Department of Radiology, University of Texas Health Science Center at Houston, Houston, Tex (D.O.); and Department of Radiology, Saint Luke's Health System, Kansas City, Mo (S.M.)
| | - Carlos Santiago Restrepo
- From the Division of Medical Imaging, Sutter Medical Group, 1500 Expo Pkwy, Sacramento, CA 95815 (H.M.); Department of Radiology (C.S.R., A.J.B.), Division of Cardiology (J.A.M.), and Department of Pathology (R.L.R.), University of Texas Health Science Center at San Antonio, San Antonio, Tex; Department of Radiology, University of Colorado Anschutz Medical Center, Aurora, Colo (D.V.); Department of Radiology, University of Texas Health Science Center at Houston, Houston, Tex (D.O.); and Department of Radiology, Saint Luke's Health System, Kansas City, Mo (S.M.)
| | - Juan Alejandro Marmol-Velez
- From the Division of Medical Imaging, Sutter Medical Group, 1500 Expo Pkwy, Sacramento, CA 95815 (H.M.); Department of Radiology (C.S.R., A.J.B.), Division of Cardiology (J.A.M.), and Department of Pathology (R.L.R.), University of Texas Health Science Center at San Antonio, San Antonio, Tex; Department of Radiology, University of Colorado Anschutz Medical Center, Aurora, Colo (D.V.); Department of Radiology, University of Texas Health Science Center at Houston, Houston, Tex (D.O.); and Department of Radiology, Saint Luke's Health System, Kansas City, Mo (S.M.)
| | - Daniel Vargas
- From the Division of Medical Imaging, Sutter Medical Group, 1500 Expo Pkwy, Sacramento, CA 95815 (H.M.); Department of Radiology (C.S.R., A.J.B.), Division of Cardiology (J.A.M.), and Department of Pathology (R.L.R.), University of Texas Health Science Center at San Antonio, San Antonio, Tex; Department of Radiology, University of Colorado Anschutz Medical Center, Aurora, Colo (D.V.); Department of Radiology, University of Texas Health Science Center at Houston, Houston, Tex (D.O.); and Department of Radiology, Saint Luke's Health System, Kansas City, Mo (S.M.)
| | - Daniel Ocazionez
- From the Division of Medical Imaging, Sutter Medical Group, 1500 Expo Pkwy, Sacramento, CA 95815 (H.M.); Department of Radiology (C.S.R., A.J.B.), Division of Cardiology (J.A.M.), and Department of Pathology (R.L.R.), University of Texas Health Science Center at San Antonio, San Antonio, Tex; Department of Radiology, University of Colorado Anschutz Medical Center, Aurora, Colo (D.V.); Department of Radiology, University of Texas Health Science Center at Houston, Houston, Tex (D.O.); and Department of Radiology, Saint Luke's Health System, Kansas City, Mo (S.M.)
| | - Santiago Martinez-Jimenez
- From the Division of Medical Imaging, Sutter Medical Group, 1500 Expo Pkwy, Sacramento, CA 95815 (H.M.); Department of Radiology (C.S.R., A.J.B.), Division of Cardiology (J.A.M.), and Department of Pathology (R.L.R.), University of Texas Health Science Center at San Antonio, San Antonio, Tex; Department of Radiology, University of Colorado Anschutz Medical Center, Aurora, Colo (D.V.); Department of Radiology, University of Texas Health Science Center at Houston, Houston, Tex (D.O.); and Department of Radiology, Saint Luke's Health System, Kansas City, Mo (S.M.)
| | - Robert Lee Reddick
- From the Division of Medical Imaging, Sutter Medical Group, 1500 Expo Pkwy, Sacramento, CA 95815 (H.M.); Department of Radiology (C.S.R., A.J.B.), Division of Cardiology (J.A.M.), and Department of Pathology (R.L.R.), University of Texas Health Science Center at San Antonio, San Antonio, Tex; Department of Radiology, University of Colorado Anschutz Medical Center, Aurora, Colo (D.V.); Department of Radiology, University of Texas Health Science Center at Houston, Houston, Tex (D.O.); and Department of Radiology, Saint Luke's Health System, Kansas City, Mo (S.M.)
| | - Ameya Jagdish Baxi
- From the Division of Medical Imaging, Sutter Medical Group, 1500 Expo Pkwy, Sacramento, CA 95815 (H.M.); Department of Radiology (C.S.R., A.J.B.), Division of Cardiology (J.A.M.), and Department of Pathology (R.L.R.), University of Texas Health Science Center at San Antonio, San Antonio, Tex; Department of Radiology, University of Colorado Anschutz Medical Center, Aurora, Colo (D.V.); Department of Radiology, University of Texas Health Science Center at Houston, Houston, Tex (D.O.); and Department of Radiology, Saint Luke's Health System, Kansas City, Mo (S.M.)
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5
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Bertelsen L, Svendsen JH, Køber L, Haugan K, Højberg S, Thomsen C, Vejlstrup N. Flow measurement at the aortic root - impact of location of through-plane phase contrast velocity mapping. J Cardiovasc Magn Reson 2016; 18:55. [PMID: 27599727 PMCID: PMC5013573 DOI: 10.1186/s12968-016-0277-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 08/25/2016] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Cardiovascular magnetic resonance (CMR) is considered the gold standard of cardiac volumetric measurements. Flow in the aortic root is often measured at the sinotubular junction, even though placing the slice just above valve level may be more precise. It is unknown how much flow measurements vary at different levels in the aortic root and which level corresponds best to left ventricle volumetry. METHODS All patients were older than 70 years presenting with at least one of the following diagnoses: diabetes, hypertension, prior stroke and/or heart failure. Patients with arrhythmias during CMR and aortic stenosis were excluded from the analyses. Stroke volumes were measured volumetrically (SVref) from steady-state free precision short axis images covering the entire left ventricle, excluding the papillary muscles and including the left ventricular outflow tract. Flow sequences (through-plane phase contrast velocity mapping) were obtained at valve level (SVV) and at the sinotubular junction (SVST). Firstly, SVV and SVST were compared to each other and secondly, after excluding patients with mitral regurgitations to ensure that stroke volumes measured volumetrically would theoretically be equal to flow measurements, SVV and SVST were compared to SVref. RESULTS Initially, 152 patients were included. 22 were excluded because of arrhythmias during scans and 9 were excluded for aortic stenosis. Accordingly, data from 121 patients were analysed and of these 63 had visually evident mitral regurgitation on cine images. On average, stroke volumes measured with flow at the sinotubular junction was 13-16 % lower than when measured at valve level (70.0 mL ±13.8 vs. 81.8 mL ±15.5). This was in excess of the expected difference caused by the outflow to the coronary arteries. In the 58 patients with no valvulopathy, stroke volumes measured at valve level (79.0 mL ±12.4) was closest to the volumetric measurement (85.4 mL ±12.0) but still significantly lower (p < 0.001). Flow measured at the ST-junction (68.1 mL ±11.6) was significantly lower than at valve level and the volumetric measurements. The mean difference between SVref-SVV (6.4 mL) and SVref-SVST (18.2 mL) showed similar variances (SD 7.4 vs. 8.1 respectively) and hence equal accuracy. CONCLUSIONS Aortic flow measured at valve level corresponded best with volumetric measurements and on average flow measured at the sinotubular junction underestimated flow approximately 15 % compared to valve level. TRIAL REGISTRATION ClinicalTrials.gov identifier: NCT02036450 . Registered 08/01/2014.
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Affiliation(s)
- Litten Bertelsen
- Department of Cardiology, The Heart Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Jesper Hastrup Svendsen
- Department of Cardiology, The Heart Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
- Danish National Research Foundation Centre for Cardiac Arrhythmia (DARC), Copenhagen, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lars Køber
- Department of Cardiology, The Heart Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Ketil Haugan
- Department of Cardiology, Roskilde Hospital, Roskilde, Denmark
| | - Søren Højberg
- Department of Cardiology Y, Bispebjerg Hospital, Copenhagen, Denmark
| | - Carsten Thomsen
- Department of Radiology, The Diagnostic Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Niels Vejlstrup
- Department of Cardiology, The Heart Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
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Körperich H, Barth P, Gieseke J, Müller K, Burchert W, Esdorn H, Kececioglu D, Beerbaum P, Laser KT. Impact of respiration on stroke volumes in paediatric controls and in patients after Fontan procedure assessed by MR real-time phase-velocity mapping. Eur Heart J Cardiovasc Imaging 2014; 16:198-209. [PMID: 25246504 DOI: 10.1093/ehjci/jeu179] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
AIMS Blood flow rate quantification using two-dimensional phase-contrast MRI (PC-MRI) results in averaging of flow information due to long acquisition times precluding the examination of short-term effects. The aim of this study was to determine respiration-related flow rate variations by non-electrocardiographic triggered real-time phase-contrast MRI (PC-MRI). METHODS AND RESULTS Real-time PC-MRI was applied to study respiration-driven blood flow fluctuations in the ascending aorta (AAo), superior vena cava (SVC), and inferior vena cava (IVC) under normal and forced breathing in 33 healthy children and 10 Fontan patients. Respiration-dependent flow rates were virtually generated by dividing the respiration curve into four segments: expiration, end-expiration, inspiration, and end-inspiration. Whereas in volunteers aortic flow rate was elevated during end-expiration (5.6 ± 3.0%) and decreased during end-inspiration (-5.8 ± 3.5%) in relation to mean blood flow (P < 0.05), highest flow was detected during inspiration in SVC (10.5 ± 14.1%) and IVC (22.5 ± 12.1%) and lowest flow during expiration (-11.6 ± 13.5%, -13.2 ± 14.1%, P < 0.05). Differences were increased under forced breathing in AAo (10.4 ± 5.5%, -7.4 ± 6.5%, P < 0.05) and SVC (40.0 ± 30.3%, -30.0 ± 19.2%, P < 0.05), whereas were unchanged in IVC (16.5 ± 23.6%, -13.7 ± 21.6%, P = n.s.). Regarding patients, respiratory-dependent flow rate variability was increased and had to be related to the patient's individual quality of Fontan circulation. CONCLUSION Real-time PC-MRI allows a physiological assessment of respiratory-related flow rate fluctuations in healthy subjects as well as in Fontan patients. Its capability for detection of short-term effects in clinical routine was demonstrated.
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Affiliation(s)
- Hermann Körperich
- Institute for Radiology, Nuclear Medicine and Molecular Imaging, Heart and Diabetes Center Northrhine-Westfalia, Ruhr-University of Bochum, Georgstraße 11, D-32545 Bad Oeynhausen, Germany
| | - Peter Barth
- Institute for Radiology, Nuclear Medicine and Molecular Imaging, Heart and Diabetes Center Northrhine-Westfalia, Ruhr-University of Bochum, Georgstraße 11, D-32545 Bad Oeynhausen, Germany
| | | | - Katja Müller
- Center for Congenital Heart Defects, Heart and Diabetes Centre Northrhine-Westfalia, Ruhr-University of Bochum, Bad Oeynhausen, Germany
| | - Wolfgang Burchert
- Institute for Radiology, Nuclear Medicine and Molecular Imaging, Heart and Diabetes Center Northrhine-Westfalia, Ruhr-University of Bochum, Georgstraße 11, D-32545 Bad Oeynhausen, Germany
| | - Hermann Esdorn
- Institute for Radiology, Nuclear Medicine and Molecular Imaging, Heart and Diabetes Center Northrhine-Westfalia, Ruhr-University of Bochum, Georgstraße 11, D-32545 Bad Oeynhausen, Germany
| | - Deniz Kececioglu
- Center for Congenital Heart Defects, Heart and Diabetes Centre Northrhine-Westfalia, Ruhr-University of Bochum, Bad Oeynhausen, Germany
| | - Philipp Beerbaum
- Medizinische Hochschule Hannover, Kinderheilkunde, Pädiatrische Kardiologie und Pädiatrische Intensivmedizin, Hannover, Germany
| | - Kai Thorsten Laser
- Center for Congenital Heart Defects, Heart and Diabetes Centre Northrhine-Westfalia, Ruhr-University of Bochum, Bad Oeynhausen, Germany
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7
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Kowallick JT, Joseph AA, Unterberg-Buchwald C, Fasshauer M, van Wijk K, Merboldt KD, Voit D, Frahm J, Lotz J, Sohns JM. Real-time phase-contrast flow MRI of the ascending aorta and superior vena cava as a function of intrathoracic pressure (Valsalva manoeuvre). Br J Radiol 2014; 87:20140401. [PMID: 25074791 DOI: 10.1259/bjr.20140401] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE Real-time phase-contrast flow MRI at high spatiotemporal resolution was applied to simultaneously evaluate haemodynamic functions in the ascending aorta (AA) and superior vena cava (SVC) during elevated intrathoracic pressure (Valsalva manoeuvre). METHODS Real-time phase-contrast flow MRI at 3 T was based on highly undersampled radial gradient-echo acquisitions and phase-sensitive image reconstructions by regularized non-linear inversion. Dynamic alterations of flow parameters were obtained for 19 subjects at 40-ms temporal resolution, 1.33-mm in-plane resolution and 6-mm section thickness. Real-time measurements were performed during normal breathing (10 s), increased intrathoracic pressure (10 s) and recovery (20 s). RESULTS Real-time measurements were technically successful in all volunteers. During the Valsalva manoeuvre (late strain) and relative to values during normal breathing, the mean peak flow velocity and flow volume decreased significantly in both vessels (p < 0.001) followed by a return to normal parameters within the first 10 s of recovery in the AA. By contrast, flow in the SVC presented with a brief (1-2 heartbeats) but strong overshoot of both the peak velocity and blood volume immediately after pressure release followed by rapid normalization. CONCLUSION Real-time phase-contrast flow MRI may assess cardiac haemodynamics non-invasively, in multiple vessels, across the entire luminal area and at high temporal and spatial resolution. ADVANCES IN KNOWLEDGE Future clinical applications of this technique promise new insights into haemodynamic alterations associated with pre-clinical congestive heart failure or diastolic dysfunction, especially in cases where echocardiography is technically compromised.
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Affiliation(s)
- J T Kowallick
- 1 Institute for Diagnostic and Interventional Radiology, Heart Center, University Medical Center Göttingen, Göttingen, Germany
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8
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Claessen G, Claus P, Delcroix M, Bogaert J, Gerche AL, Heidbuchel H. Interaction between respiration and right versus left ventricular volumes at rest and during exercise: a real-time cardiac magnetic resonance study. Am J Physiol Heart Circ Physiol 2014; 306:H816-24. [DOI: 10.1152/ajpheart.00752.2013] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Breathing-induced changes in intrathoracic pressures influence left ventricular (LV) and right ventricular (RV) volumes, the exact nature and extent of which have not previously been evaluated in humans. We sought to examine this “respiratory pump” using novel real-time cardiac magnetic resonance (CMR) imaging. Eight healthy subjects underwent serial multislice real-time CMR during normal breathing, breath holding, and the Valsalva maneuver. Subsequently, a separate cohort of nine subjects underwent real-time CMR at rest and during incremental exercise. LV and RV end-diastolic volume (EDV) and end-systolic volume (ESV) and diastolic and systolic eccentricity indexes were determined at peak inspiration and expiration. During normal breathing, inspiration resulted in an increase in RV volumes [RVEDV: +18 ± 8%, RVESV: +14 ± 12%, and RV stroke volume (SV): +21 ± 10%, P < 0.01] and an opposing decrease in LV volumes ( P < 0.0001 for interaction). During end-inspiratory breath holding, RV SV decreased by 9 ± 10% ( P = 0.046), whereas LV SV did not change. During the Valsalva maneuver, volumes decreased in both ventricles (RVEDV: −29 ± 11%, RVESV: −16 ± 14%, RV SV: −36 ± 14%, LVEDV: −22 ± 17%, and LV SV: −25 ± 17%, P < 0.01). The reciprocal effect of respiration on LV and RV volumes was maintained throughout exercise. The diastolic and systolic eccentricity indexes were greater during inspiration than during expiration, both at rest and during exercise ( P < 0.0001 for both). In conclusion, ventricular volumes oscillate with respiratory phase such that RV and LV volumes are maximal at peak inspiration and expiration, respectively. Thus, interpretation of RV versus LV volumes requires careful definition of the exact respiratory time point for proper interpretation, both at rest and during exercise.
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Affiliation(s)
- Guido Claessen
- Department of Cardiovascular Medicine, University Hospitals Leuven, Leuven, Belgium
| | - Piet Claus
- Department of Cardiovascular Imaging and Dynamics, University of Leuven, Leuven, Belgium
| | - Marion Delcroix
- Department of Pneumology, University Hospitals Leuven, Leuven, Belgium
| | - Jan Bogaert
- Department of Radiology, University Hospitals Leuven, Leuven, Belgium; and
| | - Andre La Gerche
- Department of Cardiovascular Medicine, University Hospitals Leuven, Leuven, Belgium
- St Vincent's Hospital Department of Medicine, University of Melbourne, Fitzroy, South Australia, Australia
| | - Hein Heidbuchel
- Department of Cardiovascular Medicine, University Hospitals Leuven, Leuven, Belgium
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Rigsby CK, Hilpipre N, McNeal GR, Zhang G, Boylan EE, Popescu AR, Choi G, Greiser A, Deng J. Analysis of an automated background correction method for cardiovascular MR phase contrast imaging in children and young adults. Pediatr Radiol 2014; 44:265-73. [PMID: 24306733 DOI: 10.1007/s00247-013-2830-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Revised: 09/16/2013] [Accepted: 10/21/2013] [Indexed: 11/28/2022]
Abstract
BACKGROUND Phase contrast magnetic resonance imaging (MRI) is a powerful tool for evaluating vessel blood flow. Inherent errors in acquisition, such as phase offset, eddy currents and gradient field effects, can cause significant inaccuracies in flow parameters. These errors can be rectified with the use of background correction software. OBJECTIVE To evaluate the performance of an automated phase contrast MRI background phase correction method in children and young adults undergoing cardiac MR imaging. MATERIALS AND METHODS We conducted a retrospective review of patients undergoing routine clinical cardiac MRI including phase contrast MRI for flow quantification in the aorta (Ao) and main pulmonary artery (MPA). When phase contrast MRI of the right and left pulmonary arteries was also performed, these data were included. We excluded patients with known shunts and metallic implants causing visible MRI artifact and those with more than mild to moderate aortic or pulmonary stenosis. Phase contrast MRI of the Ao, mid MPA, proximal right pulmonary artery (RPA) and left pulmonary artery (LPA) using 2-D gradient echo Fast Low Angle SHot (FLASH) imaging was acquired during normal respiration with retrospective cardiac gating. Standard phase image reconstruction and the automatic spatially dependent background-phase-corrected reconstruction were performed on each phase contrast MRI dataset. Non-background-corrected and background-phase-corrected net flow, forward flow, regurgitant volume, regurgitant fraction, and vessel cardiac output were recorded for each vessel. We compared standard non-background-corrected and background-phase-corrected mean flow values for the Ao and MPA. The ratio of pulmonary to systemic blood flow (Qp:Qs) was calculated for the standard non-background and background-phase-corrected data and these values were compared to each other and for proximity to 1. In a subset of patients who also underwent phase contrast MRI of the MPA, RPA, and LPA a comparison was made between standard non-background-corrected and background-phase-corrected mean combined flow in the branch pulmonary arteries and MPA flow. All comparisons were performed using the Wilcoxon sign rank test (α = 0.05). RESULTS Eighty-five children and young adults (mean age 14 years; range 10 days to 32 years) met the criteria for inclusion. Background-phase-corrected mean flow values for the Ao and MPA were significantly lower than those for non-background-corrected standard Ao (P = 0.0004) and MPA flow values (P < 0.0001), respectively. However, no significant difference was seen between the standard non-background (P = 0.295) or background-phase-corrected (P = 0.0653) mean Ao and MPA flow values. Neither the mean standard non-background-corrected (P = 0.408) nor the background-phase-corrected (P = 0.0684) Qp:Qs was significantly different from 1. However in the 27 patients with standard non-background-corrected data, the difference between the Ao and MPA flow values was greater than 10%. There were 19 patients with background-phase-corrected data in which the difference between the Ao and MPA flow values was greater than 10%. In the subset of 43 patients who underwent MPA and branch pulmonary artery phase contrast MRI, the sum of the standard non-background-corrected mean RPA and LPA flow values was significantly different from the standard non-background-corrected mean MPA flow (P = 0.0337). The sum of the background-phase-corrected mean RPA and LPA flow values was not significantly different from the background-phase-corrected mean MPA flow value (P = 0.1328), suggesting improvement in pulmonary artery flow calculations using background-phase-correction. CONCLUSION Our data suggest that background phase correction of phase contrast MRI data does not significantly change Qp:Qs quantification, and there are residual errors in expected Qp:Qs quantification despite background phase correction. However the use of background phase correction does improve quantification of MPA flow relative to combined RPA and LPA flow. Further work is needed to validate these findings in other patient populations, using other MRI units, and across vendors.
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Affiliation(s)
- Cynthia K Rigsby
- Department of Medical Imaging, Ann & Robert H. Lurie Children's Hospital of Chicago, 225 E. Chicago Ave, Box 9, Chicago, IL, 60611, USA,
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Pike D, Lindenmaier TJ, Sin DD, Parraga G. Imaging evidence of the relationship between atherosclerosis and chronic obstructive pulmonary disease. ACTA ACUST UNITED AC 2014. [DOI: 10.2217/iim.13.70] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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11
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Evaluation of hemodynamic changes by use of phase-contrast MRI for patients with interstitial pneumonia, with special focus on blood flow reduction after breath-holding and bronchopulmonary shunt flow. Jpn J Radiol 2012; 31:197-203. [DOI: 10.1007/s11604-012-0171-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 11/27/2012] [Indexed: 11/25/2022]
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Georgiopoulou VV, Kalogeropoulos AP, Psaty BM, Rodondi N, Bauer DC, Butler AB, Koster A, Smith AL, Harris TB, Newman AB, Kritchevsky SB, Butler J. Lung function and risk for heart failure among older adults: the Health ABC Study. Am J Med 2011; 124:334-41. [PMID: 21435424 PMCID: PMC3073738 DOI: 10.1016/j.amjmed.2010.12.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2010] [Revised: 12/04/2010] [Accepted: 12/06/2010] [Indexed: 11/18/2022]
Abstract
BACKGROUND The impact of abnormal spirometric findings on risk for incident heart failure among older adults without clinically apparent lung disease is not well elucidated. METHODS We evaluated the association of baseline lung function with incident heart failure, defined as first hospitalization for heart failure, in 2125 participants of the community-based Health, Aging, and Body Composition (Health ABC) Study (age, 73.6 ± 2.9 years; 50.5% men; 62.3% white; 37.7% black) without prevalent lung disease or heart failure. Abnormal lung function was defined either as forced vital capacity (FVC) or forced expiratory volume in 1(st) second (FEV(1)) to FVC ratio below lower limit of normal. Percent predicted FVC and FEV(1) also were assessed as continuous variables. RESULTS During follow-up (median, 9.4 years), heart failure developed in 68 of 350 (19.4%) participants with abnormal baseline lung function, as compared with 172 of 1775 (9.7%) participants with normal lung function (hazard ratio [HR] 2.31; 95% confidence interval [CI], 1.74-3.07; P <.001). This increased risk persisted after adjusting for previously identified heart failure risk factors in the Health ABC Study, body mass index, incident coronary heart disease, and inflammatory markers (HR 1.83; 95% CI, 1.33-2.50; P <.001). Percent predicted (%) FVC and FEV(1) had a linear association with heart failure risk (HR 1.21; 95% CI, 1.11-1.32 and 1.18; 95% CI, 1.10-1.26, per 10% lower %FVC and %FEV(1), respectively; both P <.001 in fully adjusted models). Findings were consistent in sex and race subgroups and for heart failure with preserved or reduced ejection fraction. CONCLUSIONS Abnormal spirometric findings in older adults without clinical lung disease are associated with increased heart failure risk.
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Assessment of left ventricular diastolic function by MR: why, how and when. Insights Imaging 2010; 1:183-192. [PMID: 22347914 PMCID: PMC3259379 DOI: 10.1007/s13244-010-0026-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Accepted: 05/11/2010] [Indexed: 01/19/2023] Open
Abstract
Cardiovascular magnetic resonance (CMR), a valuable non-invasive technique for the evaluation of the cardiovascular system, has already been accepted as the "gold standard" for the assessment of systolic function. The assessment of diastolic function is important not only for diagnosis purposes, but also in terms of prognosis. ECG-triggering phase-contrast (PC) CMR allows the routine assessment of diastolic function by measuring the transmitral and pulmonary venous flow with high accuracy and reproducibility, using morphological and quantitative parameters similar to those obtained by transthoracic echocardiography, which are so familiar to general cardiologists. Therefore, the increasing role of CMR in the assessment of the cardiovascular system requires a greater awareness and knowledge of this condition by radiologists. The aim of this study is to review the main mechanisms and common causes of left ventricle diastolic dysfunction, provide a practical approach for the assessment of LV diastolic function and illustrate the different degrees of diastolic dysfunction.
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Zuber M, Roos M, Kobza R, Toggweiler S, Meier R, Erne P. Detection and Hemodynamic Significance of Cardiac Pacemaker-Induced Phrenic Nerve Stimulation. ACTA ACUST UNITED AC 2010; 16:147-52. [DOI: 10.1111/j.1751-7133.2010.00157.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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15
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Cîndea N, Odille F, Bosser G, Felblinger J, Vuissoz PA. Reconstruction from free-breathing cardiac MRI data using reproducing kernel Hilbert spaces. Magn Reson Med 2009; 63:59-67. [PMID: 20027598 DOI: 10.1002/mrm.22170] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
This paper describes a rigorous framework for reconstructing MR images of the heart, acquired continuously over the cardiac and respiratory cycle. The framework generalizes existing techniques, commonly referred to as retrospective gating, and is based on the properties of reproducing kernel Hilbert spaces. The reconstruction problem is formulated as a moment problem in a multidimensional reproducing kernel Hilbert spaces (a two-dimensional space for cardiac and respiratory resolved imaging). Several reproducing kernel Hilbert spaces were tested and compared, including those corresponding to commonly used interpolation techniques (sinc-based and splines kernels) and a more specific kernel allowed by the framework (based on a first-order Sobolev RKHS). The Sobolev reproducing kernel Hilbert spaces was shown to allow improved reconstructions in both simulated and real data from healthy volunteers, acquired in free breathing.
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Bogaert J, Francone M. Cardiovascular magnetic resonance in pericardial diseases. J Cardiovasc Magn Reson 2009; 11:14. [PMID: 19413898 PMCID: PMC2685792 DOI: 10.1186/1532-429x-11-14] [Citation(s) in RCA: 136] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2008] [Accepted: 05/04/2009] [Indexed: 02/06/2023] Open
Abstract
The pericardium and pericardial diseases in particular have received, in contrast to other topics in the field of cardiology, relatively limited interest. Today, despite improved knowledge of pathophysiology of pericardial diseases and the availability of a wide spectrum of diagnostic tools, the diagnostic challenge remains. Not only the clinical presentation may be atypical, mimicking other cardiac, pulmonary or pleural diseases; in developed countries a shift for instance in the epidemiology of constrictive pericarditis has been noted. Accurate decision making is crucial taking into account the significant morbidity and mortality caused by complicated pericardial diseases, and the potential benefit of therapeutic interventions. Imaging herein has an important role, and cardiovascular magnetic resonance (CMR) is definitely one of the most versatile modalities to study the pericardium. It fuses excellent anatomic detail and tissue characterization with accurate evaluation of cardiac function and assessment of the haemodynamic consequences of pericardial constraint on cardiac filling. This review focuses on the current state of knowledge how CMR can be used to study the most common pericardial diseases.
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Affiliation(s)
- Jan Bogaert
- Department of Radiology, UZ Leuven, B-3000 Leuven, Belgium
| | - Marco Francone
- Department of Radiology, University of La Sapienza, Rome, Italy
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Effects of breath-hold and cardiac cycle on the MRI appearance of the aorta and inferior vena cava in t2 abdominal imaging. AJR Am J Roentgenol 2009; 192:1348-58. [PMID: 19380560 DOI: 10.2214/ajr.08.1646] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The purpose of this article is to review the MR principles of blood signal and normal flow-related phenomena seen in the aorta and inferior vena cava (IVC) on T2-weighted images of the abdomen and to discuss the physiologic and physical basis of signal alterations with breath-hold imaging. We define time-of-flight (TOF) loss and list the factors that affect it; explain the physiologic effects of breath-hold imaging on both aortic and IVC waveforms and velocity; state which abdominal T2 imaging techniques are most susceptible to variable TOF effects and explain why based on physiologic effects and MR principles; and describe three trouble-shooting techniques to confirm that unexpected signal does not reflect pathology. CONCLUSION T2 images customarily result in TOF loss and dark blood signal. Abdominal MRI relies extensively on breath-hold imaging techniques that may alter markedly the flow velocity in normal vessels. This marked flow change results in signal heterogeneity and variable TOF loss especially with faster sequences filling k-space in shorter time frames. Breath-hold imaging decreases k-space fill time, and of the breath-hold T2 techniques, single-shot fast spin-echo decreases k-space fill time the most. Atypical blood signal during breath-hold imaging may mimic pathology, but abnormal findings can be verified by review of other sequences and planes of imaging.
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The Valsalva maneuver: screening for drug-induced baroreflex dysfunction. Clin Auton Res 2008; 19:32-8. [PMID: 19011931 DOI: 10.1007/s10286-008-0508-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2008] [Accepted: 10/21/2008] [Indexed: 10/21/2022]
Abstract
OBJECTIVE Many drugs can interfere with baroreflex mechanisms thereby impairing blood pressure control, but few have undergone sufficient testing. The state of affairs may be explained by the lack of simple and inexpensive screening tests. METHODS In eleven healthy men, we tested the hypothesis that a simple Valsalva maneuver could detect drug-induced changes in baroreflex function that have previously been described using more elaborate and invasive methodologies. They performed Valsalva maneuvers after selective pharmacological inhibition of the norepinephrine transporter (NET) in a placebo-controlled, double-blind, randomized, crossover fashion. Patients with severe autonomic failure served as positive controls. RESULTS NET inhibition profoundly augmented the blood pressure decrease during phase II and attenuated the blood pressure overshoot in phase IV compared with placebo. Furthermore, NET inhibition increased the heart rate response during the Valsalva maneuver. INTERPRETATION The Valsalva maneuver recapitulated complex alterations in baroreflex regulation during NET inhibition. Thus, this simple and inexpensive test could be employed as a screening tool for drug-induced baroreflex dysfunction.
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Nogami M, Ohno Y, Higashino T, Takenaka D, Yoshikawa T, Koyama H, Kawamitsu H, Fujii M, Sugimura K. Influences of prolonged apnea and oxygen inhalation on pulmonary hemodynamics during breath holding: Quantitative assessment by velocity-encoded MR imaging with SENSE technique. Eur J Radiol 2007; 64:375-80. [PMID: 17904323 DOI: 10.1016/j.ejrad.2007.02.043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2007] [Revised: 02/02/2007] [Accepted: 02/02/2007] [Indexed: 10/22/2022]
Abstract
PURPOSE The purpose of our study was to assess the influence of prolonged apnea and administration of oxygen on pulmonary hemodynamics during breath holding (BH) by using velocity-encoded MR imaging combined with the SENSE technique (velocity MRI). MATERIALS AND METHODS Ten healthy male volunteers underwent velocity MRI during BH with and without O(2) inhalation. All velocity MRI data sets were obtained continuously with the 2D cine phase-contrast method during a single BH period. The data were then divided into three BH time phases as follows: first, second and third. To evaluate the influence of prolonged apnea on hemodynamics, stroke volume (SV) and maximal change in flow rate during ejection (MCFR) of second and third phases were statistically compared with those of first phase by using the ANOVA followed by Turkey's HSD multiple comparison test. To assess the influence of O(2) on hemodynamics, SV and MCFR with or without O(2) were compared by the paired t-test. To assess the measuring agreement of hemodynamic indices during prolonged breath holding, Bland-Altman's analysis was performed. RESULTS Prolonged apnea had no significant influence on SV and MCFR regardless of administration of O(2) (p>0.05). Mean MCFR for all phases was significantly lower with administration of O(2) than without (p<0.05). The limits of agreement for MCFR with O(2) were smaller than without. CONCLUSION O(2) inhalation modulated maximal change in flow rate during ejection, and did not influence stroke volume during breath holding. Influence of O(2) inhalation should be considered for MR measurements of pulmonary hemodynamics during breath holding.
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Affiliation(s)
- Munenobu Nogami
- 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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21
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Thompson RB, McVeigh ER. Cardiorespiratory-resolved magnetic resonance imaging: measuring respiratory modulation of cardiac function. Magn Reson Med 2007; 56:1301-10. [PMID: 17058205 PMCID: PMC2041918 DOI: 10.1002/mrm.21075] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A technique for cardiac- and respiratory-resolved MRI is described. A retrospectively gated-segmented acquisition scheme similar to that used in conventional cine cardiac imaging was used to collect image data that spanned both the cardiac and respiratory cycles. Raw k-space data were regridded in a cardiorespiratory phase space to allow image reconstruction at target cardiac and respiratory phases. The approach can be applied with various k-space trajectories and pulse sequences, and was implemented in this study with both a Cartesian steady-state free precession (SSFP) sequence and a radial phase-contrast (PC) pulse sequence. Free-breathing short-axis SSFP images of the heart were reconstructed at multiple respiratory and cardiac phases to illustrate separation of cardiac and respiratory motion without artifacts. A respiratory-resolved radial PC experiment was used to quantify the volumetric flow rates in the inferior vena cava (IVC), pulmonary artery (PA), and aorta (Ao) in five free-breathing normal volunteers and a positive-pressure ventilated dog. Total flow (ml/min) in each vessel was quantified as a function of respiratory phase (peak/minimum output = 1.85 +/- 0.29 (IVC), 1.36 +/- 0.15 (PA), 1.24 +/- 0.09 (Ao)). Peak flow occurred during inspiration for the IVC and PA, and during expiration for the Ao, and there was a complete pattern reversal for the positive-pressure ventilated dog.
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Affiliation(s)
- Richard B Thompson
- Department of Biomedical Engineering, University of Alberta, Edmonton, Canada.
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22
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Ley S, Mereles D, Puderbach M, Gruenig E, Schöck H, Eichinger M, Ley-Zaporozhan J, Fink C, Kauczor HU. Value of MR phase-contrast flow measurements for functional assessment of pulmonary arterial hypertension. Eur Radiol 2007; 17:1892-7. [PMID: 17225131 DOI: 10.1007/s00330-006-0559-9] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2006] [Revised: 10/24/2006] [Accepted: 12/04/2006] [Indexed: 10/23/2022]
Abstract
Goals of our study were to compare the pulmonary hemodynamics between healthy volunteers and patients with pulmonary arterial hypertension (PAH) and correlate MR flow measurements with echocardiography. Twenty-five patients with PAH and 25 volunteers were examined at 1.5 T. Phase-contrast flow measurements were performed in the ascending aorta and pulmonary trunk, resulting in the following parameters: peak velocity (cm/s), average blood flow (l/min), time to peak velocity (ms), velocity rise gradient and pulmonary distensibility (cm(2)). The bronchosystemic shunt was calculated. In PAH patients transthoracic echocardiography and right-heart catheterization (RHC) served as the gold standard. In comparison to volunteers, the PAH patients showed significantly reduced pulmonary velocities (P = 0.002), blood flow (P = 0.002) and pulmonary distensibility (P = 0.008). In patients, the time to peak velocity was shorter (P<0.001), and the velocity rise gradient was steeper (P = 0.002) than in volunteers. While in volunteers the peak velocity in the aorta was reached earlier, it was the reverse in patients. Patients showed a significant bronchosystemic shunt (P = 0.01). No meaningful correlation was found between MRI measurements and echocardiography or RHC. MRI is a feasible technique for the differentiation between PAH and volunteers. Further studies have to be conducted for the absolute calculation of pressure estimates.
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Affiliation(s)
- Sebastian Ley
- Department of Radiology (E010), German Cancer Research Center DKFZ, Heidelberg, Germany.
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23
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Park JB, Hu BS, Conolly SM, Nayak KS, Nishimura DG. Rapid cardiac-output measurement with ungated spiral phase contrast. Magn Reson Med 2006; 56:432-8. [PMID: 16802317 DOI: 10.1002/mrm.20970] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
An ungated spiral phase-contrast (USPC) method was used to measure cardiac output (CO) rapidly and conveniently. The USPC method, which was originally designed for small peripheral vessels, was modified to assess CO by measuring flow in the ascending aorta (AA). The modified USPC used a 12-interleaf spiral trajectory to acquire full-image data every 283 ms with 2-mm spatial resolution. The total scan time was 5 s. For comparison, a triggered real-time (TRT) method was used to indirectly calculate CO by measuring left-ventricular (LV) volume. The USPC and TRT measurements from all normal volunteers agreed. In a patient with patent ductus arteriosus (PDA), high CO was measured with USPC, which agreed well with the invasive cardiac-catheterized measurement. In normal volunteers, CO dropped about 20-30% with Valsalva maneuvering, and increased about 100% after exercise. Continuous 28-s cycling between Valsalva maneuvering and free-breathing showed that USPC can temporally resolve physiological CO changes.
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Affiliation(s)
- Jong B Park
- Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California, USA.
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Ley S, Fink C, Puderbach M, Zaporozhan J, Plathow C, Eichinger M, Hosch W, Kreitner KF, Kauczor HU. MRI Measurement of the hemodynamics of the pulmonary and systemic arterial circulation: influence of breathing maneuvers. AJR Am J Roentgenol 2006; 187:439-44. [PMID: 16861549 DOI: 10.2214/ajr.04.1738] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The purpose of this study was to use phase-contrast MRI to evaluate the influence of various breathing maneuvers on the hemodynamics of the pulmonary and systemic arterial circulation. SUBJECTS AND METHODS Twenty-five volunteers were examined with phase-contrast MRI. Flow measurements were acquired in the aorta, pulmonary trunk, and left and right pulmonary arteries during deep, large-volume inspiratory breath-hold, expiratory breath-hold, and smooth respiration (no breath-hold). Parameters assessed were peak velocity, blood flow, velocity gradient, and acceleration time. RESULTS Pulmonary blood flow and peak velocity were significantly reduced during inspiratory breath-hold and expiratory breath-hold compared with no breath-hold (p < 0.01). Pulmonary velocity gradient in inspiratory breath-hold was significantly (p </= 0.01) lower than in expiratory breath-hold and no breath-hold. There was no difference in velocity gradient between expiratory breath-hold and no breath-hold. Peak velocity in the aorta was lowest with no breath-hold. Velocity gradient was highest in expiratory breath-hold, and no breath-hold had the smallest SD. Acceleration time in the pulmonary trunk showed no difference between inspiratory breath-hold, expiratory breath-hold, and no breath-hold. Blood flow distribution to the left (45-47%) and to the right (53-55%) lung was not influenced by breathing maneuver. CONCLUSION Measurements during smooth respiration showed the smallest SD. Therefore, no-breath-hold measurements should be considered for assessment of hemodynamics in clinical practice.
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Affiliation(s)
- Sebastian Ley
- Department of Radiology (E010), German Cancer Research Center, (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
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Francone M, Dymarkowski S, Kalantzi M, Bogaert J. Real-time cine MRI of ventricular septal motion: a novel approach to assess ventricular coupling. J Magn Reson Imaging 2005; 21:305-9. [PMID: 15723377 DOI: 10.1002/jmri.20259] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The purpose of this study was to assess the feasibility of magnetic resonance imaging (MRI) to evaluate in real-time, the effects of respiration in ventricular septal motion and configuration in normal volunteers and cardiac patients. Real-time cine MRI studies, using the steady-state free precession (SSFP) technique, were performed in the cardiac short-axis during operator-guided deep inspiration and expiration in normal volunteers (N = 6), and in patients with constrictive pericarditis (CP; N = 6), restrictive cardiomyopathy (RCM; N = 4), chronic cor pulmonale (N = 5), and pericardial effusion. The respiratory effects on septal position and configuration during early ventricular filling were visually assessed. Results were compared with the short-axis breath-hold cine MRI studies, obtained at end-inspiration. In CP patients, onset of inspiration led to a leftward inversion in four of six patients and flattening of the septum in two of six patients during early ventricular filling. Septal abnormalities progressively disappeared during the following heartbeats. A similar pattern was found in one of six patients with pericardial effusion. The above pattern was absent in RCM patients. Although septal flattening during early inspiration was also found in two of six normal volunteers, flattening was minimal compared to that in CP patients. In all cor pulmonale patients, septal flattening or inversion was present, but this was not influenced by respiratory motion. Real-time cine MRI is a promising technique for determining the influence of respiration on septal motion and might be helpful in differentiating between different causes of impaired ventricular filling.
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Affiliation(s)
- Marco Francone
- Department of Radiology, Gasthuisberg University Hospital, Leuven, Belgium
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Gatehouse PD, Keegan J, Crowe LA, Masood S, Mohiaddin RH, Kreitner KF, Firmin DN. Applications of phase-contrast flow and velocity imaging in cardiovascular MRI. Eur Radiol 2005; 15:2172-84. [PMID: 16003509 DOI: 10.1007/s00330-005-2829-3] [Citation(s) in RCA: 204] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2005] [Accepted: 05/31/2005] [Indexed: 10/25/2022]
Abstract
A review of cardiovascular clinical and research applications of MRI phase-contrast velocity imaging, also known as velocity mapping or flow imaging. Phase-contrast basic principles, advantages, limitations, common pitfalls and artefacts are described. It can measure many different aspects of the complicated blood flow in the heart and vessels: volume flow (cardiac output, shunt, valve regurgitation), peak blood velocity (for stenosis), patterns and timings of velocity waveforms and flow distributions within heart chambers (abnormal ventricular function) and vessels (pulse-wave velocity, vessel wall disease). The review includes phase-contrast applications in cardiac function, heart valves, congenital heart diseases, major blood vessels, coronary arteries and myocardial wall velocity.
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Affiliation(s)
- Peter D Gatehouse
- Royal Brompton Hospital and National Heart and Lung Institute, Imperial College, London, UK.
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27
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Ley S, Puderbach M, Fink C, Eichinger M, Plathow C, Teiner S, Wiebel M, Müller FM, Kauczor HU. Assessment of hemodynamic changes in the systemic and pulmonary arterial circulation in patients with cystic fibrosis using phase-contrast MRI. Eur Radiol 2005; 15:1575-80. [PMID: 15761712 DOI: 10.1007/s00330-005-2721-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2004] [Revised: 02/01/2005] [Accepted: 02/17/2005] [Indexed: 10/25/2022]
Abstract
Cystic fibrosis (CF) leads to disabling lung disease and pulmonary hypertension (PH). The goal of this study was to assess the hemodynamics in the systemic and pulmonary arterial circulation of patients with CF using MRI. Ten patients with CF and 15 healthy volunteers were examined (1.5-T MRI). Phase-contrast flow measurements were assessed in the ascending aorta, pulmonary trunc, and the left and right pulmonary arteries (PA), resulting in the following parameters: peak velocity (PV) (centimeters per second) velocity rise gradient (VRG), time to PV (milliseconds), and the average area (centimeters squared). The blood flow ratio between the right and left lungs and the bronchosystemic shunt were calculated. For the ascending aorta and pulmonary trunc no parameter was significantly different between both populations. In the right PA a significantly lower PV (p=0.001) and VRG (p=0.02) was found. In the left PA there was a significantly (p=0.007) lower PV but no significant (p=0.07) difference between the VRG. The areas of the right (p=0.08) and left (p=0.5) PA were not significantly enlarged. For the volunteers a linear increase of PV in both PA was found with age, while it decreased in patients with CF. The blood flow distribution (right/left lung) showed no significant (p=0.7) difference between the groups. There was a significantly (p<0.001) higher bronchosystemic shunt volume in patients with CF (1.3 l/min) than in volunteers (0.1 l/min). Magnetic resonance based flow measurements in the right and left PA showed first indications for early development of PH. The significant increase in bronchosystemic shunt volume might be indicative fo the extent of parenchymal changes.
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Affiliation(s)
- Sebastian Ley
- Department of Radiology (E010), DKFZ, Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.
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Abstract
This article reviews common cardiovascular pathologies that can be noted first on plain film when previously unsuspected, and then illustrates how cross-sectional imaging can provide the follow-up information needed to make a diagnosis. First reviewed are the normal cardiac structures and contours as seen on the plain film of the chest, followed by specific types of pathologies as seen in older adults; patients with lung cancer invading the heart, pericardium, or large vessels; and postsurgical and posttraumatic findings. Also provided is a review of non-cardiac-related areas of plain film and cross-sectional imaging correlation. It is hoped that the reader gains a better understanding and appreciation for the great value of cross-sectional imaging, and the power of the plain film in helping detect and recognize thoracic pathology.
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Affiliation(s)
- André J Duerinckx
- Radiology Service, Veterans Affairs North Texas Healthcare System, Dallas, TX 75126, USA.
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