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Traser L, Burk F, Özen AC, Burdumy M, Bock M, Blaser D, Richter B, Echternach M. Respiratory kinematics and the regulation of subglottic pressure for phonation of pitch jumps - a dynamic MRI study. PLoS One 2020; 15:e0244539. [PMID: 33382744 PMCID: PMC7775092 DOI: 10.1371/journal.pone.0244539] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 12/11/2020] [Indexed: 11/18/2022] Open
Abstract
The respiratory system is a central part of voice production as it contributes to the generation of subglottic pressure, which has an impact on voice parameters including fundamental frequency and sound pressure level. Both parameters need to be adjusted precisely during complex phonation tasks such as singing. In particular, the underlying functions of the diaphragm and rib cage in relation to the phonation of pitch jumps are not yet understood in detail. This study aims to analyse respiratory movements during phonation of pitch jumps using dynamic MRI of the lungs. Dynamic images of the breathing apparatus of 7 professional singers were acquired in the supine position during phonation of upwards and downwards pitch jumps in a high, medium, and low range of the singer's tessitura. Distances between characteristic anatomical landmarks in the lung were measured from the series of images obtained. During sustained phonation, the diaphragm elevates, and the rib cage is lowered in a monotonic manner. During downward pitch jumps the diaphragm suddenly changed its movement direction and presented with a short inspiratory activation which was predominant in the posterior part and was associated with a shift of the cupola in an anterior direction. The magnitude of this inspiratory movement was greater for jumps that started at higher compared to lower fundamental frequency. In contrast, expiratory movement of the rib cage and anterior diaphragm were simultaneous and continued constantly during the jump. The data underline the theory of a regulation of subglottic pressure via a sudden diaphragm contraction during phonation of pitch jumps downwards, while the rib cage is not involved in short term adaptations. This strengthens the idea of a differentiated control of rib cage and diaphragm as different functional units during singing phonation.
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Affiliation(s)
- Louisa Traser
- Institute of Musicians’ Medicine, Medical Center–University of Freiburg, Freiburg, Germany
- Division of Phoniatrics, Department of Otorhinolaryngology, Head Neck Surgery, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- * E-mail:
| | - Fabian Burk
- Department of Otorhinolaryngology, Head- and Neck Surgery, Christian-Albrechts-University, Kiel, Germany
| | - Ali Caglar Özen
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Radiology, Medical Physics, Medical Center–University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- German Consortium for Translational Cancer Research Partner Site Freiburg, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Michael Burdumy
- Department of Radiology, Medical Physics, Medical Center–University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Michael Bock
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Radiology, Medical Physics, Medical Center–University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Daniela Blaser
- Division of Phoniatrics, Department of Otorhinolaryngology, Head Neck Surgery, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Bernhard Richter
- Institute of Musicians’ Medicine, Medical Center–University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Matthias Echternach
- Division of Phoniatrics and Pediatric Audiology, Department of Otorhinolaryngology, Munich University Hospital, Munich, Germany
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Eirich P, Wech T, Heidenreich JF, Stich M, Petri N, Nordbeck P, Bley TA, Köstler H. Cardiac real-time MRI using a pre-emphasized spiral acquisition based on the gradient system transfer function. Magn Reson Med 2020; 85:2747-2760. [PMID: 33270942 DOI: 10.1002/mrm.28621] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 10/21/2020] [Accepted: 11/10/2020] [Indexed: 12/28/2022]
Abstract
PURPOSE Segmented Cartesian acquisition in breath hold represents the current gold standard for cardiac functional MRI. However, it is also associated with long imaging times and severe restrictions in arrhythmic or dyspneic patients. Therefore, we introduce a real-time imaging technique based on a spoiled gradient-echo sequence with undersampled spiral k-space trajectories corrected by a gradient pre-emphasis. METHODS A fully automatic gradient waveform pre-emphasis based on the gradient system transfer function was implemented to compensate for gradient inaccuracies, to optimize fast double-oblique spiral MRI. The framework was tested in a phantom study and subsequently transferred to compressed sensing-accelerated cardiac functional MRI in real time. Spiral acquisitions during breath hold and free breathing were compared with this reference method for healthy subjects (N = 7) as well as patients (N = 2) diagnosed with heart failure and arrhythmia. Left-ventricular volumes and ejection fractions were determined and analyzed using a Wilcoxon signed-rank test. RESULTS The pre-emphasis successfully reduced typical artifacts caused by k-space misregistrations. Dynamic cardiac imaging was possible in real time (temporal resolution < 50 ms) with high spatial resolution (1.34 × 1.34 mm2 ), resulting in a total scan time of less than 50 seconds for whole heart coverage. Comparable image quality, as well as similar left-ventricular volumes and ejection fractions, were observed for the accelerated and the reference method. CONCLUSION The proposed technique enables high-resolution real-time cardiac MRI with no need for breath holds and electrocardiogram gating, shortening the duration of an entire functional cardiac exam to less than 1 minute.
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Affiliation(s)
- Philipp Eirich
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Würzburg, Germany.,Comprehensive Heart Failure Center Würzburg, Würzburg, Germany
| | - Tobias Wech
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Würzburg, Germany
| | - Julius F Heidenreich
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Würzburg, Germany
| | - Manuel Stich
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Würzburg, Germany
| | - Nils Petri
- Department of Internal Medicine I, University Hospital Würzburg, Würzburg, Germany
| | - Peter Nordbeck
- Department of Internal Medicine I, University Hospital Würzburg, Würzburg, Germany
| | - Thorsten A Bley
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Würzburg, Germany
| | - Herbert Köstler
- Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Würzburg, Germany
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Reichert A, Reiss S, Krafft AJ, Bock M. Passive needle guide tracking with radial acquisition and phase-only cross-correlation. Magn Reson Med 2020; 85:1039-1046. [PMID: 32767451 DOI: 10.1002/mrm.28448] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 07/07/2020] [Accepted: 07/07/2020] [Indexed: 12/24/2022]
Abstract
PURPOSE Acceleration of a passive tracking sequence based on phase-only cross-correlation (POCC) using radial undersampling. METHODS The phase-only cross-correlation (POCC) algorithm allows passive tracking of interventional instruments in real-time. In a POCC sequence, two cross-sectional images of a needle guide with a positive MR contrast are continuously acquired from which the instrument trajectory is calculated. Conventional Cartesian imaging for tracking is very time consuming; here, a higher temporal resolution is achieved using a highly undersampled radial acquisition together with a modified POCC algorithm that incorporates the point-spread-function. Targeting and needle insertion is performed in two phantom experiments with 16 fiducial targets, each using 4 and 16 radial projections for passive tracking. Additionally, targeting of eight deep lying basivertebral veins in the lumbar spines is performed for in vivo proof-of-application with four radial projections for needle guide tracking. RESULTS The radially undersampled POCC sequence yielded in the phantom experiments a lateral targeting accuracy of 1.1 ± 0.4 mm and 1.0 ± 0.5 mm for 16 and 4 radial projections, respectively, without any statistically significant difference. In the in vivo application, a mean targeting duration of 62 ± 13 s was measured. CONCLUSION Radial undersampling can drastically reduce the acquisition time for passive tracking in a POCC sequences for MR-guided needle interventions without compromising the targeting accuracy.
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Affiliation(s)
- Andreas Reichert
- Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Simon Reiss
- Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Axel Joachim Krafft
- Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Michael Bock
- Department of Radiology, Medical Physics, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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Heidt T, Reiss S, Lottner T, Özen AC, Bode C, Bock M, von Zur Mühlen C. Magnetic resonance imaging for pathobiological assessment and interventional treatment of the coronary arteries. Eur Heart J Suppl 2020; 22:C46-C56. [PMID: 32368198 PMCID: PMC7189741 DOI: 10.1093/eurheartj/suaa009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
X-ray-based fluoroscopy is the standard tool for diagnostics and intervention in coronary artery disease. In recent years, computed tomography has emerged as a non-invasive alternative to coronary angiography offering detection of coronary calcification and imaging of the vessel lumen by the use of iodinated contrast agents. Even though currently available invasive or non-invasive techniques can show the degree of vessel stenosis, they are unable to provide information about biofunctional plaque properties, e.g. plaque inflammation. Furthermore, the use of radiation and the necessity of iodinated contrast agents remain unfavourable prerequisites. Magnetic resonance imaging (MRI) is a radiation-free alternative to X-ray which offers anatomical and functional imaging contrasts fostering the idea of non-invasive biofunctional assessment of the coronary vessel wall. In combination with molecular contrast agents that target-specific epitopes of the vessel wall, MRI might reveal unique plaque properties rendering it, for example, ‘vulnerable and prone to rupture’. Early detection of these lesions may allow for early or prophylactic treatment even before an adverse coronary event occurs. Besides diagnostic imaging, advances in real-time image acquisition and motion compensation now provide grounds for MRI-guided coronary interventions. In this article, we summarize our research on MRI-based molecular imaging in cardiovascular disease and feature our advances towards real-time MRI-based coronary interventions in a porcine model.
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Affiliation(s)
- Timo Heidt
- Department of Cardiology, Cardiology and Angiology I, Heart Center Freiburg University and Faculty of Medicine, Hugstetterstr. 55, 79106 Freiburg, Germany
| | - Simon Reiss
- Department of Radiology, Medical Physics, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany
| | - Thomas Lottner
- Department of Radiology, Medical Physics, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany
| | - Ali C Özen
- Department of Radiology, Medical Physics, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany.,German Cancer Consortium Partner Site Freiburg, German Cancer Research Center (DKFZ), Stefan-Meier-Str. 17, 79104 Freiburg, Germany
| | - Christoph Bode
- Department of Cardiology, Cardiology and Angiology I, Heart Center Freiburg University and Faculty of Medicine, Hugstetterstr. 55, 79106 Freiburg, Germany
| | - Michael Bock
- Department of Radiology, Medical Physics, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany
| | - Constantin von Zur Mühlen
- Department of Cardiology, Cardiology and Angiology I, Heart Center Freiburg University and Faculty of Medicine, Hugstetterstr. 55, 79106 Freiburg, Germany
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