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Ponssen D, Joseph AA, Neef NE, Frahm J, Sommer M. Visualising the dynamic morphology of stuttering using real-time MRI. Lancet 2024; 403:1789-1790. [PMID: 38704173 DOI: 10.1016/s0140-6736(24)00624-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Revised: 02/27/2024] [Accepted: 03/23/2024] [Indexed: 05/06/2024]
Affiliation(s)
- Daniela Ponssen
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Arun A Joseph
- Biomedical NMR, Max-Planck-Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Nicole E Neef
- Department of Diagnostic and Interventional Neuroradiology, University Medical Center Göttingen, Göttingen, Germany
| | - Jens Frahm
- Biomedical NMR, Max-Planck-Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Martin Sommer
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany.
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Joseph AA, Voit D, Frahm J. Inferior vena cava revisited - Real-time flow MRI of respiratory maneuvers. NMR Biomed 2020; 33:e4232. [PMID: 31913551 DOI: 10.1002/nbm.4232] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 11/05/2019] [Accepted: 11/07/2019] [Indexed: 06/10/2023]
Abstract
Recent MRI studies of blood flow in the inferior vena cava (IVC) resulted in findings which are inconsistent with earlier observations by invasive procedures - most likely because ECG-gated MRI techniques are unable to resolve dynamic adjustments due to respiration. The purpose of this work was to apply real-time phase-contrast MRI at 50 ms resolution to re-evaluate IVC flow in response to normal and deep breathing as well as breath holding and Valsalva maneuver (11 young healthy subjects). Real-time flow MRI relied on highly undersampled radial gradient-echo sequences and a model-based nonlinear inverse reconstruction. A frequency analysis of the predominant pulsatility classified IVC flow in individual subjects as "cardiac", "respiratory" or "mixed" type. Peak flow velocities during free breathing ranged from 30 to 58 cm s-1 , while flow rates varied from 15 to 37 ml s-1 . The subject-specific IVC flow pattern persists during deep breathing although the enhanced respiratory influence may shift subjects form "cardiac" to "mixed" or from "mixed" to "respiratory" type. Peak velocities increased relative to normal breathing but led to similar flow rates of 16 to 34 ml s-1 . Inspiration during deep breathing elicited brief periods of flow reversal in all subjects with mean peak velocities of -21 cm s-1 . The observation of only mildly flattened parabolic velocity distributions within the IVC indicated mostly laminar flow. Breath holding reduced blood flow velocities and rates by more than 40% on average, while Valsalva maneuvers completely abolished venous return. In conclusion, IVC blood flow is dominated by the acquired respiratory behavior of individual subjects and its pressure-induced alterations relative to cardiac pulsation. The responses to breath holding and Valsalva maneuver are in full agreement with previous invasive observations of reduced or even ceased flow, respectively.
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Affiliation(s)
- Arun A Joseph
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Dirk Voit
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Jens Frahm
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Germany
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Kollmeier JM, Tan Z, Joseph AA, Kalentev O, Voit D, Merboldt KD, Frahm J. Real-time multi-directional flow MRI using model-based reconstructions of undersampled radial FLASH - A feasibility study. NMR Biomed 2019; 32:e4184. [PMID: 31580524 DOI: 10.1002/nbm.4184] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 08/12/2019] [Accepted: 08/15/2019] [Indexed: 06/10/2023]
Abstract
The purpose of this work was to develop an acquisition and reconstruction technique for two- and three-directional (2d and 3d) phase-contrast flow MRI in real time. A previous real-time MRI technique for one-directional (1d) through-plane flow was extended to 2d and 3d flow MRI by introducing in-plane flow sensitivity. The method employs highly undersampled radial FLASH sequences with sequential acquisitions of two or three flow-encoding datasets and one flow-compensated dataset. Echo times are minimized by merging the waveforms of flow-encoding and radial imaging gradients. For each velocity direction individually, model-based reconstructions by regularized nonlinear inversion jointly estimate an anatomical image, a set of coil sensitivities and a phase-contrast velocity map directly. The reconstructions take advantage of a dynamic phase reference obtained by interpolating consecutive flow-compensated acquisitions. Validations include pulsatile flow phantoms as well as in vivo studies of the human aorta at 3 T. The proposed method offers cross-sectional 2d and 3d flow MRI of the human aortic arch at 53 and 67 ms resolution, respectively, without ECG synchronization and during free breathing. The in-plane resolution was 1.5 × 1.5 mm2 and the slice thickness 6 mm. In conclusion, real-time multi-directional flow MRI offers new opportunities to study complex human blood flow without the risk of combining differential phase (i.e., velocity) information from multiple heartbeats as for ECG-gated data. The method would benefit from a further reduction of acquisition time and accelerated computing to allow for extended clinical trials.
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Affiliation(s)
- Jost M Kollmeier
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Zhengguo Tan
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Arun A Joseph
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Germany
| | - Oleksandr Kalentev
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Dirk Voit
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - K Dietmar Merboldt
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Jens Frahm
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Germany
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Hellwig SJ, Iltis PW, Joseph AA, Voit D, Frahm J, Schoonderwaldt E, Altenmüller E. Tongue involvement in embouchure dystonia: new piloting results using real-time MRI of trumpet players. J Clin Mov Disord 2019; 6:5. [PMID: 31754440 PMCID: PMC6852982 DOI: 10.1186/s40734-019-0080-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 10/09/2019] [Indexed: 11/10/2022]
Abstract
Background The embouchure of trumpet players is of utmost importance for tone production and quality of playing. It requires skilled coordination of lips, facial muscles, tongue, oral cavity, larynx and breathing and has to be maintained by steady practice. In rare cases, embouchure dystonia (EmD), a highly task specific movement disorder, may cause deterioration of sound quality and reduced control of tongue and lip movements. In order to better understand the pathophysiology of this movement disorder, we use real-time MRI to analyse differences in tongue movements between healthy trumpet players and professional players with embouchure dystonia. Methods Real-time MRI videos (with sound recording) were acquired at 55 frames per second, while 10 healthy subjects and 4 patients with EmD performed a defined set of exercises on an MRI-compatible trumpet inside a 3 Tesla MRI system. To allow for a comparison of tongue movements between players, temporal changes of MRI signal intensities were analysed along 7 standardized positions of the tongue using a customised MATLAB toolkit. Detailed results of movements within the oral cavity during performance of an ascending slurred 11-note harmonic series are presented. Results Playing trumpet in the higher register requires a very precise and stable narrowing of the free oral cavity. For this purpose the anterior section of the tongue is used as a valve in order to speed up airflow in a controlled manner. Conversely, the posterior part of the tongue is much less involved in the regulation of air speed. The results further demonstrate that healthy trumpet players control movements of the tongue rather precisely and stable during a sustained tone, whereas trumpet players with EmD exhibit much higher variability in tongue movements. Conclusion Control of the anterior tongue in trumpet playing emerges as a critical feature for regulating air speed and, ultimately, achieving a high-quality performance. In EmD the observation of less coordinated tongue movements suggests the presence of compensatory patterns in an attempt to regulate (or correct) pitch. Increased variability of the anterior tongue could be an objective sign of dystonia that has to be examined in further studies and extended to other brass instruments and may be also a potential target for therapy options.
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Affiliation(s)
| | | | - Arun A Joseph
- 3Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Dirk Voit
- 3Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Jens Frahm
- 3Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
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Voit D, Kalentev O, van Zalk M, Joseph AA, Frahm J. Rapid and motion-robust volume coverage using cross-sectional real-time MRI. Magn Reson Med 2019; 83:1652-1658. [PMID: 31670850 DOI: 10.1002/mrm.28029] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 09/13/2019] [Accepted: 09/13/2019] [Indexed: 01/29/2023]
Abstract
PURPOSE To develop a rapid and motion-robust technique for volumetric MRI, which is based on cross-sectional real-time MRI acquisitions with automatic advancement of the slice position. METHODS Real-time MRI with a frame-by-frame moving cross-section is performed with use of highly undersampled radial gradient-echo sequences offering spin density, T1 , or T2 /T1 contrast. Joint reconstructions of serial images and coil sensitivity maps from spatially overlapping sections are accomplished by nonlinear inversion with regularization to the preceding section-formally identical to dynamic real-time MRI. Shifting each frame by 20% to 25% of the section thickness ensures 75% to 80% overlap of successive sections. Acquisition times of 40 to 67 ms allow for rates of 15 to 25 sections per second, while volumes are defined by the number of cross-sections times the section shift. RESULTS Preliminary realizations at 3T comprise studies of the human brain, carotid arteries, liver, and prostate. Typically, coverage of a 90- to 180-mm volume at 0.8- to 1.2-mm in-plane resolution, 4- to 6-mm section thickness, and 0.8- to 1.5-mm section shift is accomplished within total measuring times of 4 to 6 seconds and a section speed of 15 to 37.5 mm per second. However, spatiotemporal resolution, contrast including options such as fat saturation and total measuring time are highly variable and may be adjusted to clinical needs. Promising volumetric applications range from fetal MRI to dynamic contrast-enhanced MRI. CONCLUSION The proposed method allows for rapid and motion-robust volume coverage in a variety of imaging scenarios.
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Affiliation(s)
- Dirk Voit
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Oleksandr Kalentev
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Maaike van Zalk
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Arun A Joseph
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Jens Frahm
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
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Aktas G, Kollmeier JM, Joseph AA, Merboldt KD, Ludwig HC, Gärtner J, Frahm J, Dreha-Kulaczewski S. Spinal CSF flow in response to forced thoracic and abdominal respiration. Fluids Barriers CNS 2019; 16:10. [PMID: 30947716 PMCID: PMC6449937 DOI: 10.1186/s12987-019-0130-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 03/27/2019] [Indexed: 11/15/2022] Open
Abstract
Background Respiration-induced pressure changes represent a powerful driving force of CSF dynamics as previously demonstrated using flow-sensitive real-time magnetic resonance imaging (MRI). The purpose of the present study was to elucidate the sensitivity of CSF flow along the spinal canal to forced thoracic versus abdominal respiration. Methods Eighteen subjects without known illness were studied using real-time phase-contrast flow MRI at 3 T in the aqueduct and along the spinal canal at levels C3, Th1, Th8 and L3. Subjects performed a protocol of forced breathing comprising four cycles of 2.5 s inspiration and 2.5 s expiration. Results The quantitative results for spinal CSF flow rates and volumes confirm previous findings of an upward movement during forced inspiration and reversed downward flow during subsequent exhalation—for both breathing types. However, the effects were more pronounced for abdominal than for thoracic breathing, in particular at spinal levels Th8 and L3. In general, CSF net flow volumes were very similar for both breathing conditions pointing upwards in all locations. Conclusions Spinal CSF dynamics are sensitive to varying respiratory performances. The different CSF flow volumes in response to deep thoracic versus abdominal breathing reflect instantaneous adjustments of intrathoracic and intraabdominal pressure, respectively. Real-time MRI access to CSF flow in response to defined respiration patterns will be of clinical importance for patients with disturbed CSF circulation like hydrocephalus, pseudotumor cerebri and others. Electronic supplementary material The online version of this article (10.1186/s12987-019-0130-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Gökmen Aktas
- School of Medicine, University Medical Center Göttingen, 37075, Göttingen, Germany
| | - Jost M Kollmeier
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, 37077, Göttingen, Germany
| | - Arun A Joseph
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, 37077, Göttingen, Germany.,DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, Germany
| | - Klaus-Dietmar Merboldt
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, 37077, Göttingen, Germany
| | - Hans-Christoph Ludwig
- Division of Pediatric Neurosurgery, Department of Neurosurgery, University Medical Center Göttingen, 37075, Göttingen, Germany
| | - Jutta Gärtner
- Division of Pediatric Neurology, Department of Pediatrics and Adolescent Medicine, University Medical Center Göttingen, 37075, Göttingen, Germany
| | - Jens Frahm
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, 37077, Göttingen, Germany.,DZHK (German Center for Cardiovascular Research), Partner Site Göttingen, Germany
| | - Steffi Dreha-Kulaczewski
- Division of Pediatric Neurology, Department of Pediatrics and Adolescent Medicine, University Medical Center Göttingen, 37075, Göttingen, Germany.
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Krohn S, Joseph AA, Voit D, Michaelis T, Merboldt KD, Buergers R, Frahm J. Multi-slice real-time MRI of temporomandibular joint dynamics. Dentomaxillofac Radiol 2019; 48:20180162. [PMID: 30028188 PMCID: PMC6398907 DOI: 10.1259/dmfr.20180162] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 05/29/2018] [Accepted: 06/28/2018] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVES The purpose of this work was to improve the clinical versatility of high-speed real-time MRI studies of temporomandibular joint (TMJ) dynamics by simultaneous recordings of multiple MRI movies in different sections. METHODS Real-time MRI at 3 T was realized using highly undersampled radial FLASH acquisitions and image reconstruction by regularized nonlinear inversion (NLINV). Multi-slice real-time MRI of two, three or four slices at 0.75 mm resolution and 6 to 8 mm thickness was accomplished at 50.0 ms, 33.3 ms or 25.5 ms temporal resolution, respectively, yielding simultaneous movies at 2 × 10, 3 × 10 or 4 × 10 frames per second in a frame-interleaved acquisition mode. Real-time MRI movies were evaluated by three blinded raters for visibility of the anterior and posterior border of disc, shape of the disk body and condyle head as well as movement of the disc and condyle (1 = excellent, 5 = no visibility). RESULTS Effective delineation of the disk atop the mandibular condyle was achieved by T1-weighted images with opposed-phase water-fat contrast. Compared to 8 mm sections, multi-slice recordings with 6 mm thickness provided sharper delineation of relevant structures as confirmed by inter-rater evaluation. Respective dual-slice and triple-slice recordings of a single TMJ as well as dual-slice recordings of both joints (one slice per TMJ) received the highest visibility ratings of ≤ 2 corresponding to high confidence in diagnostic content. CONCLUSIONS The improved access to TMJ dynamics by multi-slice real-time MRI will contribute to more effective treatment of temporomandibular disorders.
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Affiliation(s)
- Sebastian Krohn
- Department of Prosthodontics, University Medical Center, Göttingen, Germany
| | - Arun A Joseph
- Biomedizinische NMR, MPI für biophysikalische Chemie, Göttingen, Germany
- DZHK, German Center for Cardiovascular Research, Göttingen, Germany
| | - Dirk Voit
- Biomedizinische NMR, MPI für biophysikalische Chemie, Göttingen, Germany
| | - Thomas Michaelis
- Biomedizinische NMR, MPI für biophysikalische Chemie, Göttingen, Germany
| | | | - Ralf Buergers
- Department of Prosthodontics, University Medical Center, Göttingen, Germany
| | - Jens Frahm
- Biomedizinische NMR, MPI für biophysikalische Chemie, Göttingen, Germany
- DZHK, German Center for Cardiovascular Research, Göttingen, Germany
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Maier IL, Hofer S, Joseph AA, Merboldt KD, Eggert E, Behme D, Schregel K, von der Brelie C, Rohde V, Koch J, Psychogios MN, Frahm J, Liman J, Bähr M. Quantification of spinal cord compression using T1 mapping in patients with cervical spinal canal stenosis - Preliminary experience. Neuroimage Clin 2018; 21:101639. [PMID: 30553763 PMCID: PMC6411921 DOI: 10.1016/j.nicl.2018.101639] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 10/22/2018] [Accepted: 12/09/2018] [Indexed: 11/29/2022]
Abstract
Background Degenerative changes of the cervical spinal column are the most common cause of spinal cord lesions in the elderly. Conventional clinical, electrophysiological and radiological diagnostics of spinal cord compression are often inconsistent. Materials and methods The feasibility and diagnostic potential of a novel T1 mapping method at 0.5 mm resolution and 4 s acquisition time was evaluated in 14 patients with degenerative cervical spinal canal stenosis (SCS) and 6 healthy controls. T1 mapping was performed in axial sections of the stenosis as well as above and below. All subjects received standard T2-weighted MRI of the cervical spine (including SCS-grading 0-III), electrophysiological and clinical examinations. Results Patients revealed significantly decreased T1 relaxation times of the compressed spinal cord within the SCS (912 ± 53 ms, mean ± standard deviation) in comparison to unaffected segments above (1027 ± 39 ms, p < .001) and below (1056 ± 93 ms, p < .001). There was no difference in mean T1 in unaffected segments in patients (p = .712) or between segments in controls (p = .443). Moreover, T1 values were significantly lower in grade II (881 ± 46 ms, p = .005) than in grade I SCS (954 ± 29 ms). Patients with central conduction deficit tended to have lower T1 values within the SCS than patients without (909 ± 50 ms vs 968 ± 7 ms, p = .069). Conclusion Rapid high-resolution T1 mapping is a robust MRI method for quantifying spinal cord compression in patients with cervical SCS. It promises additional diagnostic insights and warrants more extended patient studies. Rapid T1 mapping at 0.5 mm resolution was tested in cervical spinal canal stenosis (SCS). T1 relaxation times significantly decreased within the SCS. T1 relaxation times were significantly lower in grade II vs grade I SCS. Central conduction deficits were inversely correlated with T1 relaxation time. Rapid T1 mapping robustly and accurately quantifies spinal cord compression.
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Affiliation(s)
- Ilko L Maier
- Department of Neurology, University Medical Center Göttingen, Germany.
| | - Sabine Hofer
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany.
| | - Arun A Joseph
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany; German Center for Cardiovascular Research (DZHK), partner site Göttingen, Germany
| | - K Dietmar Merboldt
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Eva Eggert
- Department of Neurology, University Medical Center Göttingen, Germany
| | - Daniel Behme
- Department of Neuroradiology, University Medical Center Göttingen, Germany
| | - Katharina Schregel
- Department of Neuroradiology, University Medical Center Göttingen, Germany
| | | | - Veit Rohde
- Department of Neurosurgery, University Medical Center Göttingen, Germany
| | - Jan Koch
- Department of Neurology, University Medical Center Göttingen, Germany
| | | | - Jens Frahm
- Biomedizinische NMR, Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany; German Center for Cardiovascular Research (DZHK), partner site Göttingen, Germany
| | - Jan Liman
- Department of Neurology, University Medical Center Göttingen, Germany
| | - Mathias Bähr
- Department of Neurology, University Medical Center Göttingen, Germany
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Maier IL, Hofer S, Joseph AA, Merboldt KD, Tan Z, Schregel K, Knauth M, Bähr M, Psychogios MN, Liman J, Frahm J. Carotid artery flow as determined by real-time phase-contrast flow MRI and neurovascular ultrasound: A comparative study of healthy subjects. Eur J Radiol 2018; 106:38-45. [PMID: 30150049 DOI: 10.1016/j.ejrad.2018.07.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Revised: 04/02/2018] [Accepted: 07/11/2018] [Indexed: 10/28/2022]
Abstract
BACKGROUND The assessment of carotid artery flow by neurovascular ultrasound (nvUS) can be complemented by real-time phase-contrast (RT-PC) flow MRI which apart from quantitative flow parameters offers velocity distributions across the entire vessel lumen. MATERIALS AND METHODS The feasibility and diagnostic potential of RT-PC flow MRI was evaluated in 20 healthy volunteers in comparison to conventional nvUS. RT-PC flow MRI at 40 ms temporal resolution and 0.8 mm in-plane resolution resulted in velocity maps with low phase noise and high spatiotemporal accuracy by exploiting respective advances of a recent nonlinear inverse model-based reconstruction. Peak-systolic velocities (PSV), end-diastolic velocities (EDV), flow volumes and comprehensive velocity profiles were determined in the common, internal and external carotid artery on both sides. RESULTS Flow characteristics such as pulsatility and individual abnormalities shown on nvUS could be reproduced and visualized in detail by RT-PC flow MRI. PSV to EDV differences revealed good agreement between both techniques, mean PSV and EDV were significantly lower and flow volumes were higher for MRI. CONCLUSION Our findings suggest that RT-PC flow MRI adds to clinical diagnostics, e.g. by alterations of dynamic velocity distributions in patients with carotid stenosis. Lower PSV and EDV values than for nvUS mainly reflect the longer MRI acquisition time which attenuates short peak velocities, while higher flow volumes benefit from a proper assessment of the true vessel lumen.
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Affiliation(s)
- Ilko L Maier
- Department of Neurology, University Medical Center Göttingen, Germany.
| | - Sabine Hofer
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany.
| | - Arun A Joseph
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany; German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, Germany.
| | - K Dietmar Merboldt
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany.
| | - Zhengguo Tan
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany.
| | - Katharina Schregel
- Department of Neuroradiology, University Medical Center Göttingen, Germany; Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Michael Knauth
- Department of Neuroradiology, University Medical Center Göttingen, Germany.
| | - Mathias Bähr
- Department of Neurology, University Medical Center Göttingen, Germany.
| | | | - Jan Liman
- Department of Neurology, University Medical Center Göttingen, Germany.
| | - Jens Frahm
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany; German Center for Cardiovascular Research (DZHK), Partner Site Göttingen, Germany.
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Seif Amir Hosseini A, Beham A, Uhlig J, Streit U, Uhlig A, Ellenrieder V, Joseph AA, Voit D, Frahm J, Uecker M, Lotz J, Biggemann L. Intra- and interobserver variability in the diagnosis of GERD by real-time MRI. Eur J Radiol 2018; 104:14-19. [DOI: 10.1016/j.ejrad.2018.04.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 04/19/2018] [Accepted: 04/25/2018] [Indexed: 01/11/2023]
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Dreha-Kulaczewski S, Konopka M, Joseph AA, Kollmeier J, Merboldt KD, Ludwig HC, Gärtner J, Frahm J. Respiration and the watershed of spinal CSF flow in humans. Sci Rep 2018; 8:5594. [PMID: 29618801 PMCID: PMC5884798 DOI: 10.1038/s41598-018-23908-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 03/15/2018] [Indexed: 11/09/2022] Open
Abstract
The dynamics of human CSF in brain and upper spinal canal are regulated by inspiration and connected to the venous system through associated pressure changes. Upward CSF flow into the head during inspiration counterbalances venous flow out of the brain. Here, we investigated CSF motion along the spinal canal by real-time phase-contrast flow MRI at high spatial and temporal resolution. Results reveal a watershed of spinal CSF dynamics which divides flow behavior at about the level of the heart. While forced inspiration prompts upward surge of CSF flow volumes in the entire spinal canal, ensuing expiration leads to pronounced downward CSF flow, but only in the lower canal. The resulting pattern of net flow volumes during forced respiration yields upward CSF motion in the upper and downward flow in the lower spinal canal. These observations most likely reflect closely coupled CSF and venous systems as both large caval veins and their anastomosing vertebral plexus react to respiration-induced pressure changes.
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Affiliation(s)
- Steffi Dreha-Kulaczewski
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Neurology, University Medical Center Göttingen, 37075, Göttingen, Germany.
| | - Mareen Konopka
- School of Medicine, University Medical Center Göttingen, 37075, Göttingen, Germany
| | - Arun A Joseph
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, 37077, Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany
| | - Jost Kollmeier
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, 37077, Göttingen, Germany
| | - Klaus-Dietmar Merboldt
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, 37077, Göttingen, Germany
| | - Hans-Christoph Ludwig
- Department of Neurosurgery, Division of Pediatric Neurosurgery, University Medical Center Göttingen, 37075, Göttingen, Germany
| | - Jutta Gärtner
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Neurology, University Medical Center Göttingen, 37075, Göttingen, Germany
| | - Jens Frahm
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, 37077, Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany
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Maier I, Hofer S, Joseph AA, Merboldt KD, Tan Z, Schregel K, Knauth M, Bähr M, Psychogios MN, Liman J, Frahm J. Abstract TP201: Carotid Artery Flow as Determined by Real-Time Phase-Contrast Flow Mri and Neurovascular Ultrasound: a Comparative Study of Healthy Subjects. Stroke 2018. [DOI: 10.1161/str.49.suppl_1.tp201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background:
The assessment of carotid artery flow by neurovascular ultrasound (nvUS) may be complemented by real-time phase-contrast (RT-PC) flow MRI which apart from quantitative flow parameters offers velocity distributions across the entire vessel lumen.
Methods:
The feasibility and diagnostic potential of RT-PC flow MRI was evaluated in 20 healthy volunteers in comparison to conventional nvUS. RT-PC flow MRI at 40 ms temporal resolution and 0.8 mm in-plane resolution resulted in velocity maps with low phase noise and high spatiotemporal accuracy by exploiting respective advances of a recent nonlinear inverse model-based reconstruction. Peak-systolic velocities (PSV), end-diastolic velocities (EDV), flow volumes and comprehensive velocity profiles were determined in the common, internal and external carotid artery on both sides.
Results:
Characteristics in pulsatility and laminar flow, including individual flow abnormalities shown on nvUS, could be reproduced and visualized in detail by RT-PC flow MRI. Fig. 1 shows a representative color-coded duplex sonography with doppler spectrum (A), flow volume measurement by RT-PC flow MRI (B) and a three-dimensional representation of through-plane velocities at peak systole (C) and end diastole (D) in the internal carotid artery. PSV to EDV differences revealed good agreement between both techniques, mean PSV and EDV were significantly lower and flow volumes were higher for MRI.
Conclusions:
Our findings suggest that RT-PC flow MRI may add to clinical diagnostics, e.g. by alterations of dynamic velocity distributions in patients with carotid stenosis. Lower PSV and EDV values than for nvUS mainly reflect the longer MRI acquisition time which attenuates short peak velocities, while higher flow volumes benefit from a proper assessment of the true vessel lumen.
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Affiliation(s)
- Ilko Maier
- Neurology, Univ Medicine Goettingen, Göttingen, Germany
| | - Sabine Hofer
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Arun A Joseph
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Klaus-Dietmar Merboldt
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Zhengguo Tan
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | | | - Michael Knauth
- Neuroradiology, Univ Medicine Goettingen, Göttingen, Germany
| | - Mathias Bähr
- Neurology, Univ Medicine Goettingen, Göttingen, Germany
| | | | - Jan Liman
- Neurology, Univ Medicine Goettingen, Göttingen, Germany
| | - Jens Frahm
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
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Tan Z, Hohage T, Kalentev O, Joseph AA, Wang X, Voit D, Merboldt KD, Frahm J. An eigenvalue approach for the automatic scaling of unknowns in model-based reconstructions: Application to real-time phase-contrast flow MRI. NMR Biomed 2017; 30. [PMID: 28960554 DOI: 10.1002/nbm.3835] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 07/25/2017] [Accepted: 08/27/2017] [Indexed: 05/13/2023]
Abstract
The purpose of this work is to develop an automatic method for the scaling of unknowns in model-based nonlinear inverse reconstructions and to evaluate its application to real-time phase-contrast (RT-PC) flow magnetic resonance imaging (MRI). Model-based MRI reconstructions of parametric maps which describe a physical or physiological function require the solution of a nonlinear inverse problem, because the list of unknowns in the extended MRI signal equation comprises multiple functional parameters and all coil sensitivity profiles. Iterative solutions therefore rely on an appropriate scaling of unknowns to numerically balance partial derivatives and regularization terms. The scaling of unknowns emerges as a self-adjoint and positive-definite matrix which is expressible by its maximal eigenvalue and solved by power iterations. The proposed method is applied to RT-PC flow MRI based on highly undersampled acquisitions. Experimental validations include numerical phantoms providing ground truth and a wide range of human studies in the ascending aorta, carotid arteries, deep veins during muscular exercise and cerebrospinal fluid during deep respiration. For RT-PC flow MRI, model-based reconstructions with automatic scaling not only offer velocity maps with high spatiotemporal acuity and much reduced phase noise, but also ensure fast convergence as well as accurate and precise velocities for all conditions tested, i.e. for different velocity ranges, vessel sizes and the simultaneous presence of signals with velocity aliasing. In summary, the proposed automatic scaling of unknowns in model-based MRI reconstructions yields quantitatively reliable velocities for RT-PC flow MRI in various experimental scenarios.
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Affiliation(s)
- Zhengguo Tan
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Thorsten Hohage
- Institut für Numerische und Angewandte Mathematik, Georg-August-Universität, Göttingen, Germany
| | - Oleksandr Kalentev
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Arun A Joseph
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
- DZHK, German Center for Cardiovascular Research, partner site Göttingen, Germany
| | - Xiaoqing Wang
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Dirk Voit
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - K Dietmar Merboldt
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Jens Frahm
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
- DZHK, German Center for Cardiovascular Research, partner site Göttingen, Germany
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Krohn S, Gersdorff N, Wassmann T, Merboldt KD, Joseph AA, Buergers R, Frahm J. Real-time MRI of the temporomandibular joint at 15 frames per second—A feasibility study. Eur J Radiol 2016; 85:2225-2230. [DOI: 10.1016/j.ejrad.2016.10.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 09/05/2016] [Accepted: 10/18/2016] [Indexed: 10/20/2022]
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Olthoff A, Joseph AA, Weidenmüller M, Riley B, Frahm J. Real-time MRI of swallowing: intraoral pressure reduction supports larynx elevation. NMR Biomed 2016; 29:1618-1623. [PMID: 27687293 DOI: 10.1002/nbm.3621] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 08/14/2016] [Accepted: 08/16/2016] [Indexed: 06/06/2023]
Abstract
The reduction in intraoral pressure during swallowing has previously been linked to bolus transport, although no such relation has yet been proven. The purpose of this work was to evaluate the time course of intraoral pressure during swallowing using simultaneous real-time magnetic resonance imaging (MRI) and dynamic pressure recordings. Real-time MRI based on highly undersampled radial fast low-angle shot (FLASH) and regularized nonlinear inverse reconstruction was performed at 3 T using a standard head coil and a mid-sagittal section covering the entire oral cavity. Voluntary swallowing (10 mL of pineapple juice or saliva) was monitored for about 30 s in 11 normal subjects at spatial and temporal resolution of 1.3 × 1.3 × 8 mm3 and 40 ms, respectively. Simultaneously, the intraoral atmospheric pressure was recorded at a resolution of 10 ms during the entire course of deglutition. Quantitative measures of bolus transport, larynx elevation and submental muscle changes were obtained from the image series. As a key result, negative intraoral pressure accompanied laryngeal elevation during swallowing in all subjects. A reduction in submental muscle length during swallowing was also observed. No correlations of maximum negative pressure with larynx elevation and submental muscle change were found. In conclusion, intraoral pressure reduction during swallowing is not connected to oral bolus transport, but supports laryngeal elevation by palatal fixation of the tongue.
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Affiliation(s)
- Arno Olthoff
- Phoniatrics and Pedaudiology, Department of Otorhinolaryngology, University Medical Center, Göttingen, Germany.
| | - Arun A Joseph
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
- DZHK, German Center for Cardiovascular Research, partner site Göttingen, Germany
| | - Matthias Weidenmüller
- Phoniatrics and Pedaudiology, Department of Otorhinolaryngology, University Medical Center, Göttingen, Germany
| | - Blake Riley
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Jens Frahm
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
- DZHK, German Center for Cardiovascular Research, partner site Göttingen, Germany
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Wang X, Joseph AA, Kalentev O, Merboldt KD, Voit D, Roeloffs VB, van Zalk M, Frahm J. High-resolution myocardial T 1 mapping using single-shot inversion recovery fast low-angle shot MRI with radial undersampling and iterative reconstruction. Br J Radiol 2016; 89:20160255. [PMID: 27759423 PMCID: PMC5604905 DOI: 10.1259/bjr.20160255] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
OBJECTIVE To develop a novel method for rapid myocardial T1 mapping at high spatial resolution. METHODS The proposed strategy represents a single-shot inversion recovery experiment triggered to early diastole during a brief breath-hold. The measurement combines an adiabatic inversion pulse with a real-time readout by highly undersampled radial FLASH, iterative image reconstruction and T1 fitting with automatic deletion of systolic frames. The method was implemented on a 3-T MRI system using a graphics processing unit-equipped bypass computer for online application. Validations employed a T1 reference phantom including analyses at simulated heart rates from 40 to 100 beats per minute. In vivo applications involved myocardial T1 mapping in short-axis views of healthy young volunteers. RESULTS At 1-mm in-plane resolution and 6-mm section thickness, the inversion recovery measurement could be shortened to 3 s without compromising T1 quantitation. Phantom studies demonstrated T1 accuracy and high precision for values ranging from 300 to 1500 ms and up to a heart rate of 100 beats per minute. Similar results were obtained in vivo yielding septal T1 values of 1246 ± 24 ms (base), 1256 ± 33 ms (mid-ventricular) and 1288 ± 30 ms (apex), respectively (mean ± standard deviation, n = 6). CONCLUSION Diastolic myocardial T1 mapping with use of single-shot inversion recovery FLASH offers high spatial resolution, T1 accuracy and precision, and practical robustness and speed. Advances in knowledge: The proposed method will be beneficial for clinical applications relying on native and post-contrast T1 quantitation.
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Affiliation(s)
- Xiaoqing Wang
- 1 Biomedizinische NMR Forschungs GmbH, Max-Planck Institut für Biophysikalische Chemie, Göttingen, Germany
| | - Arun A Joseph
- 1 Biomedizinische NMR Forschungs GmbH, Max-Planck Institut für Biophysikalische Chemie, Göttingen, Germany.,2 DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Germany
| | - Oleksandr Kalentev
- 1 Biomedizinische NMR Forschungs GmbH, Max-Planck Institut für Biophysikalische Chemie, Göttingen, Germany
| | - Klaus-Dietmar Merboldt
- 1 Biomedizinische NMR Forschungs GmbH, Max-Planck Institut für Biophysikalische Chemie, Göttingen, Germany
| | - Dirk Voit
- 1 Biomedizinische NMR Forschungs GmbH, Max-Planck Institut für Biophysikalische Chemie, Göttingen, Germany
| | - Volkert B Roeloffs
- 1 Biomedizinische NMR Forschungs GmbH, Max-Planck Institut für Biophysikalische Chemie, Göttingen, Germany
| | - Maaike van Zalk
- 1 Biomedizinische NMR Forschungs GmbH, Max-Planck Institut für Biophysikalische Chemie, Göttingen, Germany
| | - Jens Frahm
- 1 Biomedizinische NMR Forschungs GmbH, Max-Planck Institut für Biophysikalische Chemie, Göttingen, Germany.,2 DZHK (German Centre for Cardiovascular Research), partner site Göttingen, Germany
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Tan Z, Roeloffs V, Voit D, Joseph AA, Untenberger M, Merboldt KD, Frahm J. Model-based reconstruction for real-time phase-contrast flow MRI: Improved spatiotemporal accuracy. Magn Reson Med 2016; 77:1082-1093. [PMID: 26949221 DOI: 10.1002/mrm.26192] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 02/09/2016] [Accepted: 02/09/2016] [Indexed: 12/27/2022]
Abstract
PURPOSE To develop a model-based reconstruction technique for real-time phase-contrast flow MRI with improved spatiotemporal accuracy in comparison to methods using phase differences of two separately reconstructed images with differential flow encodings. METHODS The proposed method jointly computes a common image, a phase-contrast map, and a set of coil sensitivities from every pair of flow-compensated and flow-encoded datasets obtained by highly undersampled radial FLASH. Real-time acquisitions with five and seven radial spokes per image resulted in 25.6 and 35.7 ms measuring time per phase-contrast map, respectively. The signal model for phase-contrast flow MRI requires the solution of a nonlinear inverse problem, which is accomplished by an iteratively regularized Gauss-Newton method. Aspects of regularization and scaling are discussed. The model-based reconstruction was validated for a numerical and experimental flow phantom and applied to real-time phase-contrast MRI of the human aorta for 10 healthy subjects and 2 patients. RESULTS Under all conditions, and compared with a previously developed real-time flow MRI method, the proposed method yields quantitatively accurate phase-contrast maps (i.e., flow velocities) with improved spatial acuity, reduced phase noise and reduced streaking artifacts. CONCLUSION This novel model-based reconstruction technique may become a new tool for clinical flow MRI in real time. Magn Reson Med 77:1082-1093, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Zhengguo Tan
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Volkert Roeloffs
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Dirk Voit
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Arun A Joseph
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany.,DZHK, German Center for Cardiovascular Research, partner site Göttingen, Germany
| | - Markus Untenberger
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - K Dietmar Merboldt
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Jens Frahm
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany.,DZHK, German Center for Cardiovascular Research, partner site Göttingen, Germany
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18
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Sohns JM, Kowallick JT, Joseph AA, Merboldt KD, Voit D, Fasshauer M, Staab W, Frahm J, Lotz J, Unterberg-Buchwald C. Peak flow velocities in the ascending aorta-real-time phase-contrast magnetic resonance imaging vs. cine magnetic resonance imaging and echocardiography. Quant Imaging Med Surg 2015; 5:685-90. [PMID: 26682138 DOI: 10.3978/j.issn.2223-4292.2015.08.08] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
This prospective study of eight healthy volunteers evaluates peak flow velocities (PFV) in the ascending aorta using real-time phase-contrast magnetic resonance imaging (MRI) in comparison to cine phase-contrast MRI and echocardiography. Flow measurements by echocardiography and cine phase-contrast MRI with breath-holding were performed according to clinical standards. Real-time phase-contrast MRI at 40 ms temporal resolution and 1.3 mm in-plane resolution was based on highly undersampled radial fast low-angle shot (FLASH) sequences with image reconstruction by regularized nonlinear inversion (NLINV). Evaluations focused on the determination of PFV. Linear regressions and Bland-Altman plots were used for comparisons of methods. When averaged across subjects, real-time phase-contrast MRI resulted in PFV of 120±20 cm s(-1) (mean ± SD) in comparison to 122±16 cm s(-1) for cine MRI and 124±20 cm s(-1) for echocardiography. The maximum deviations between real-time phase-contrast MRI and echocardiography ranged from -20 to +14 cm s(-1) (cine MRI: -10 to +12 cm s(-1)). Thus, in general, real-time phase-contrast MRI of cardiac outflow revealed quantitative agreement with cine MRI and echocardiography. The advantages of real-time MRI are measurements during free breathing and access to individual cardiac cycles.
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Affiliation(s)
- Jan M Sohns
- 1 Institute for Diagnostic and Interventional Radiology, Heart Center, University Medical Center Göttingen, Göttingen, Germany ; 2 German Centre for Cardiovascular Research, DZHK, partnersite Göttingen, Germany ; 3 Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany ; 4 Department of Cardiology and Pneumology, Heart Center, University Medical Center Göttingen, Göttingen, Germany
| | - Johannes T Kowallick
- 1 Institute for Diagnostic and Interventional Radiology, Heart Center, University Medical Center Göttingen, Göttingen, Germany ; 2 German Centre for Cardiovascular Research, DZHK, partnersite Göttingen, Germany ; 3 Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany ; 4 Department of Cardiology and Pneumology, Heart Center, University Medical Center Göttingen, Göttingen, Germany
| | - Arun A Joseph
- 1 Institute for Diagnostic and Interventional Radiology, Heart Center, University Medical Center Göttingen, Göttingen, Germany ; 2 German Centre for Cardiovascular Research, DZHK, partnersite Göttingen, Germany ; 3 Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany ; 4 Department of Cardiology and Pneumology, Heart Center, University Medical Center Göttingen, Göttingen, Germany
| | - K Dietmar Merboldt
- 1 Institute for Diagnostic and Interventional Radiology, Heart Center, University Medical Center Göttingen, Göttingen, Germany ; 2 German Centre for Cardiovascular Research, DZHK, partnersite Göttingen, Germany ; 3 Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany ; 4 Department of Cardiology and Pneumology, Heart Center, University Medical Center Göttingen, Göttingen, Germany
| | - Dirk Voit
- 1 Institute for Diagnostic and Interventional Radiology, Heart Center, University Medical Center Göttingen, Göttingen, Germany ; 2 German Centre for Cardiovascular Research, DZHK, partnersite Göttingen, Germany ; 3 Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany ; 4 Department of Cardiology and Pneumology, Heart Center, University Medical Center Göttingen, Göttingen, Germany
| | - Martin Fasshauer
- 1 Institute for Diagnostic and Interventional Radiology, Heart Center, University Medical Center Göttingen, Göttingen, Germany ; 2 German Centre for Cardiovascular Research, DZHK, partnersite Göttingen, Germany ; 3 Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany ; 4 Department of Cardiology and Pneumology, Heart Center, University Medical Center Göttingen, Göttingen, Germany
| | - Wieland Staab
- 1 Institute for Diagnostic and Interventional Radiology, Heart Center, University Medical Center Göttingen, Göttingen, Germany ; 2 German Centre for Cardiovascular Research, DZHK, partnersite Göttingen, Germany ; 3 Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany ; 4 Department of Cardiology and Pneumology, Heart Center, University Medical Center Göttingen, Göttingen, Germany
| | - Jens Frahm
- 1 Institute for Diagnostic and Interventional Radiology, Heart Center, University Medical Center Göttingen, Göttingen, Germany ; 2 German Centre for Cardiovascular Research, DZHK, partnersite Göttingen, Germany ; 3 Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany ; 4 Department of Cardiology and Pneumology, Heart Center, University Medical Center Göttingen, Göttingen, Germany
| | - Joachim Lotz
- 1 Institute for Diagnostic and Interventional Radiology, Heart Center, University Medical Center Göttingen, Göttingen, Germany ; 2 German Centre for Cardiovascular Research, DZHK, partnersite Göttingen, Germany ; 3 Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany ; 4 Department of Cardiology and Pneumology, Heart Center, University Medical Center Göttingen, Göttingen, Germany
| | - Christina Unterberg-Buchwald
- 1 Institute for Diagnostic and Interventional Radiology, Heart Center, University Medical Center Göttingen, Göttingen, Germany ; 2 German Centre for Cardiovascular Research, DZHK, partnersite Göttingen, Germany ; 3 Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany ; 4 Department of Cardiology and Pneumology, Heart Center, University Medical Center Göttingen, Göttingen, Germany
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Shabir I, Khurana ML, Joseph AA, Eunice M, Mehta M, Ammini AC. Phenotype, genotype and gender identity in a large cohort of patients from India with 5α-reductase 2 deficiency. Andrology 2015; 3:1132-9. [PMID: 26453174 DOI: 10.1111/andr.12108] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 07/27/2015] [Accepted: 08/19/2015] [Indexed: 11/30/2022]
Abstract
Deficiency of the 5α-reductase 2 enzyme impairs the conversion of testosterone to dihydrotestosterone (DHT) and differentiation of external genitalia, seminal vesicles and prostate in males. The present study describes the phenotype, genotype and gender identity in a large cohort of patients with 5αRD2. All patients underwent detailed clinical evaluation, hormonal profile, karyotyping and molecular analysis of the SRD5A2 gene. The molecular analysis of the SRD5A2 gene showed the presence of mutant alleles in 24 patients. We found 6 novel mutations IVS(1-2) T>C, p.A52T, 188-189insTA, 904-905ins A, p.A12T and p.E57X in our patients. All patients had ambiguous genitalia and the degrees of under-virilization ranged from penoscrotal hypospadias and microphallus to clitoromegaly. The position of gonads was variable in patients with same mutation. All the patients with mutations in the SRD5A2 gene had male gender identity. Those reared as female had gender dysphoria and underwent gender reassignment. Though a specific genotype-phenotype correlation could not be established in our patient but confirming the diagnosis of 5αRD2 with assessment of the SRD5A2 gene may help in appropriate gender assignment.
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Affiliation(s)
- I Shabir
- Department of Endocrinology & Metabolism, All India Institute of Medical Sciences, New Delhi, India
| | - M L Khurana
- Department of Endocrinology & Metabolism, All India Institute of Medical Sciences, New Delhi, India
| | - A A Joseph
- Department of Psychiatry, All India Institute of Medical Sciences, New Delhi, India
| | - M Eunice
- Department of Endocrinology & Metabolism, All India Institute of Medical Sciences, New Delhi, India
| | - M Mehta
- Department of Psychiatry, All India Institute of Medical Sciences, New Delhi, India
| | - A C Ammini
- Department of Endocrinology & Metabolism, All India Institute of Medical Sciences, New Delhi, India
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Zhang S, Joseph AA, Gross L, Ghadimi M, Frahm J, Beham AW. Diagnosis of Gastroesophageal Reflux Disease Using Real-time Magnetic Resonance Imaging. Sci Rep 2015; 5:12112. [PMID: 26175205 PMCID: PMC4648433 DOI: 10.1038/srep12112] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 04/30/2015] [Indexed: 12/31/2022] Open
Abstract
A small angle (His angle) between the oesophagus and the fundus of the stomach is considered to act as flap valve and anti-reflux barrier. A wide angle results in dysfunction of the oesophagogastric junction and subsequently in gastroesophageal reflux disease (GERD). Here, we used real-time magnetic resonance imaging (MRI) at 50 ms resolution (20 frames per second) in 12 volunteers and 12 patients with GERD to assess transport of pineapple juice through the oesophagogastric junction and reflux during Valsalva. We found that the intra-abdominal part of the oesophagus was bended towards the left side resulting in an angle of 75.3 ± 17.4, which was significantly larger during Valsava (P = 0.017). Reflux and several underlying pathologies were detected in 11 out of 12 patients. Our data visualize oesophagogastric junction physiology and disprove the flap valve hypothesis. Further, non-invasive real-time MRI has considerable potential for the diagnosis of causative pathologies leading to GERD.
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Affiliation(s)
- Shuo Zhang
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Arun A Joseph
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Lisa Gross
- Department of Surgery, University Medical Center, Göttingen, Germany
| | - Michael Ghadimi
- Department of Surgery, University Medical Center, Göttingen, Germany
| | - Jens Frahm
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Alexander W Beham
- Department of Surgery, University Medical Center, Göttingen, Germany
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Untenberger M, Tan Z, Voit D, Joseph AA, Roeloffs V, Merboldt KD, Schätz S, Frahm J. Advances in real-time phase-contrast flow MRI using asymmetric radial gradient echoes. Magn Reson Med 2015; 75:1901-8. [PMID: 26096085 DOI: 10.1002/mrm.25696] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 02/17/2015] [Accepted: 02/24/2015] [Indexed: 11/11/2022]
Abstract
PURPOSE To provide multidimensional velocity compensation for real-time phase-contrast flow MRI. METHODS The proposed method introduces asymmetric gradient echoes for highly undersampled radial FLASH MRI with phase-sensitive image reconstruction by regularized nonlinear inversion (NLINV). Using an adapted gradient delay correction the resulting image quality was analyzed by simulations and experimentally validated at 3 Tesla. For real-time flow MRI the reduced gradient-echo timing allowed for the incorporation of velocity-compensating waveforms for all imaging gradients at even shorter repetition times. RESULTS The results reveal a usable degree of 20% asymmetry. Real-time flow MRI with full velocity compensation eliminated signal void in a flow phantom, confirmed flow parameters in healthy subjects and demonstrated signal recovery and phase conservation in a patient with aortic valve insufficiency and stenosis. Exemplary protocols at 1.4-1.5 mm resolution and 6 mm slice thickness achieved total acquisition times of 33.3-35.7 ms for two images (7 spokes each) with and without flow-encoding gradient. CONCLUSION Asymmetric gradient echoes were successfully implemented for highly undersampled radial trajectories. The resulting temporal gain offers full velocity compensation for real-time phase-contrast flow MRI which minimizes false-positive contributions from complex flow and further enhances the temporal resolution compared with acquisitions with symmetric echoes.
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Affiliation(s)
- Markus Untenberger
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Zhengguo Tan
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Dirk Voit
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Arun A Joseph
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany.,DZHK, German Center for Cardiovascular Research, partner site Göttingen, Germany
| | - Volkert Roeloffs
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - K Dietmar Merboldt
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Sebastian Schätz
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Jens Frahm
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany.,DZHK, German Center for Cardiovascular Research, partner site Göttingen, Germany
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Iltis PW, Frahm J, Voit D, Joseph AA, Schoonderwaldt E, Altenmüller E. High-speed real-time magnetic resonance imaging of fast tongue movements in elite horn players. Quant Imaging Med Surg 2015; 5:374-81. [PMID: 26029640 DOI: 10.3978/j.issn.2223-4292.2015.03.02] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Accepted: 02/27/2015] [Indexed: 12/23/2022]
Abstract
This paper describes the use of high-speed real-time (RT) magnetic resonance imaging (MRI) in quantifying very rapid motor function within the oropharyngeal cavity of six elite horn players. Based on simultaneous sound recordings, the efficacy of RT-MRI films at 30 and 100 frames per second (fps) was assessed for tongue movements associated with double tonguing performance. Serial images with a nominal temporal resolution of 10.0 and 33.3 ms were obtained by highly undersampled radial fast low-angle shot (FLASH) sequences (5 and 17 spokes, respectively) using complementary sets of spokes for successive acquisitions (extending over 9 and 5 frames, respectively). Reconstructions of high-speed images were obtained by temporally regularized nonlinear inversion (NLINV) as previously described. A customized MATLAB toolkit was developed for the extraction of line profiles from MRI films to quantify temporal phenomena associated with task performance. The analyses reveal that for the present setting, which required the use of a temporal median filter to optimize image quality, acquisition rates of 30 fps are inadequate to accurately detect tongue movements during double tonguing, but that rates of 100 fps do allow for a precise quantification of movement. These data for the first time demonstrate the extreme performance of elite horn players. High-speed RT-MRI offers so far unavailable opportunities to study the oropharyngeal movements during brass playing with future potential for teaching and the treatment of patients suffering from dystonia.
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Affiliation(s)
- Peter W Iltis
- 1 Department of Kinesiology, Gordon College, Wenham, MA, USA ; 2 University of Music, Drama and Media, Hannover, Germany ; 3 Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Jens Frahm
- 1 Department of Kinesiology, Gordon College, Wenham, MA, USA ; 2 University of Music, Drama and Media, Hannover, Germany ; 3 Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Dirk Voit
- 1 Department of Kinesiology, Gordon College, Wenham, MA, USA ; 2 University of Music, Drama and Media, Hannover, Germany ; 3 Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Arun A Joseph
- 1 Department of Kinesiology, Gordon College, Wenham, MA, USA ; 2 University of Music, Drama and Media, Hannover, Germany ; 3 Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Erwin Schoonderwaldt
- 1 Department of Kinesiology, Gordon College, Wenham, MA, USA ; 2 University of Music, Drama and Media, Hannover, Germany ; 3 Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Eckart Altenmüller
- 1 Department of Kinesiology, Gordon College, Wenham, MA, USA ; 2 University of Music, Drama and Media, Hannover, Germany ; 3 Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
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Zhang S, Joseph AA, Voit D, Schaetz S, Merboldt KD, Unterberg-Buchwald C, Hennemuth A, Lotz J, Frahm J. Real-time magnetic resonance imaging of cardiac function and flow-recent progress. Quant Imaging Med Surg 2014; 4:313-29. [PMID: 25392819 DOI: 10.3978/j.issn.2223-4292.2014.06.03] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2014] [Accepted: 05/30/2014] [Indexed: 11/14/2022]
Abstract
Cardiac structure, function and flow are most commonly studied by ultrasound, X-ray and magnetic resonance imaging (MRI) techniques. However, cardiovascular MRI is hitherto limited to electrocardiogram (ECG)-synchronized acquisitions and therefore often results in compromised quality for patients with arrhythmias or inabilities to comply with requested protocols-especially with breath-holding. Recent advances in the development of novel real-time MRI techniques now offer dynamic imaging of the heart and major vessels with high spatial and temporal resolution, so that examinations may be performed without the need for ECG synchronization and during free breathing. This article provides an overview of technical achievements, physiological validations, preliminary patient studies and translational aspects for a future clinical scenario of cardiovascular MRI in real time.
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Affiliation(s)
- Shuo Zhang
- 1 Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen 37070, Germany ; 2 DZHK (German Cardiovascular Research Center), partner site Göttingen, Göttingen, Germany ; 3 Diagnostische und Interventionelle Radiologie, 4 Kardiologie und Pneumologie, Universitätsmedizin Göttingen, Göttingen 37075, Germany ; 5 Fraunhofer MEVIS Institute for Medical Image Computing, Bremen, Germany
| | - Arun A Joseph
- 1 Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen 37070, Germany ; 2 DZHK (German Cardiovascular Research Center), partner site Göttingen, Göttingen, Germany ; 3 Diagnostische und Interventionelle Radiologie, 4 Kardiologie und Pneumologie, Universitätsmedizin Göttingen, Göttingen 37075, Germany ; 5 Fraunhofer MEVIS Institute for Medical Image Computing, Bremen, Germany
| | - Dirk Voit
- 1 Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen 37070, Germany ; 2 DZHK (German Cardiovascular Research Center), partner site Göttingen, Göttingen, Germany ; 3 Diagnostische und Interventionelle Radiologie, 4 Kardiologie und Pneumologie, Universitätsmedizin Göttingen, Göttingen 37075, Germany ; 5 Fraunhofer MEVIS Institute for Medical Image Computing, Bremen, Germany
| | - Sebastian Schaetz
- 1 Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen 37070, Germany ; 2 DZHK (German Cardiovascular Research Center), partner site Göttingen, Göttingen, Germany ; 3 Diagnostische und Interventionelle Radiologie, 4 Kardiologie und Pneumologie, Universitätsmedizin Göttingen, Göttingen 37075, Germany ; 5 Fraunhofer MEVIS Institute for Medical Image Computing, Bremen, Germany
| | - Klaus-Dietmar Merboldt
- 1 Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen 37070, Germany ; 2 DZHK (German Cardiovascular Research Center), partner site Göttingen, Göttingen, Germany ; 3 Diagnostische und Interventionelle Radiologie, 4 Kardiologie und Pneumologie, Universitätsmedizin Göttingen, Göttingen 37075, Germany ; 5 Fraunhofer MEVIS Institute for Medical Image Computing, Bremen, Germany
| | - Christina Unterberg-Buchwald
- 1 Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen 37070, Germany ; 2 DZHK (German Cardiovascular Research Center), partner site Göttingen, Göttingen, Germany ; 3 Diagnostische und Interventionelle Radiologie, 4 Kardiologie und Pneumologie, Universitätsmedizin Göttingen, Göttingen 37075, Germany ; 5 Fraunhofer MEVIS Institute for Medical Image Computing, Bremen, Germany
| | - Anja Hennemuth
- 1 Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen 37070, Germany ; 2 DZHK (German Cardiovascular Research Center), partner site Göttingen, Göttingen, Germany ; 3 Diagnostische und Interventionelle Radiologie, 4 Kardiologie und Pneumologie, Universitätsmedizin Göttingen, Göttingen 37075, Germany ; 5 Fraunhofer MEVIS Institute for Medical Image Computing, Bremen, Germany
| | - Joachim Lotz
- 1 Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen 37070, Germany ; 2 DZHK (German Cardiovascular Research Center), partner site Göttingen, Göttingen, Germany ; 3 Diagnostische und Interventionelle Radiologie, 4 Kardiologie und Pneumologie, Universitätsmedizin Göttingen, Göttingen 37075, Germany ; 5 Fraunhofer MEVIS Institute for Medical Image Computing, Bremen, Germany
| | - Jens Frahm
- 1 Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen 37070, Germany ; 2 DZHK (German Cardiovascular Research Center), partner site Göttingen, Göttingen, Germany ; 3 Diagnostische und Interventionelle Radiologie, 4 Kardiologie und Pneumologie, Universitätsmedizin Göttingen, Göttingen 37075, Germany ; 5 Fraunhofer MEVIS Institute for Medical Image Computing, Bremen, Germany
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Untenberger M, Hüllebrand M, Tautz L, Joseph AA, Voit D, Merboldt KD, Frahm J. Spatiotemporal phase unwrapping for real-time phase-contrast flow MRI. Magn Reson Med 2014; 74:964-70. [DOI: 10.1002/mrm.25471] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 08/29/2014] [Accepted: 09/01/2014] [Indexed: 11/06/2022]
Affiliation(s)
- Markus Untenberger
- Biomedizinische NMR Forschungs GmbH am Max-Planck Institut für biophysikalische Chemie; Göttingen Germany
| | - Markus Hüllebrand
- Fraunhofer MEVIS Institute for Medical Image Computing; Bremen Germany
| | - Lennart Tautz
- Fraunhofer MEVIS Institute for Medical Image Computing; Bremen Germany
| | - Arun A. Joseph
- Biomedizinische NMR Forschungs GmbH am Max-Planck Institut für biophysikalische Chemie; Göttingen Germany
- German Center for Cardiovascular Research (DZHK); Göttingen Germany
| | - Dirk Voit
- Biomedizinische NMR Forschungs GmbH am Max-Planck Institut für biophysikalische Chemie; Göttingen Germany
| | - K. Dietmar Merboldt
- Biomedizinische NMR Forschungs GmbH am Max-Planck Institut für biophysikalische Chemie; Göttingen Germany
| | - Jens Frahm
- Biomedizinische NMR Forschungs GmbH am Max-Planck Institut für biophysikalische Chemie; Göttingen Germany
- German Center for Cardiovascular Research (DZHK); Göttingen Germany
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Fasshauer M, Joseph AA, Kowallick JT, Unterberg-Buchwald C, Merboldt KD, Voit D, Steinmetz M, Staab W, Schaetz S, Zhang S, Frahm J, Lotz J, Sohns JM. Real-time phase-contrast flow MRI of haemodynamic changes in the ascending aorta and superior vena cava during Mueller manoeuvre. Clin Radiol 2014; 69:1066-71. [PMID: 25060931 DOI: 10.1016/j.crad.2014.06.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 06/01/2014] [Accepted: 06/03/2014] [Indexed: 10/25/2022]
Abstract
AIM To evaluate the potential of real-time phase-contrast flow magnetic resonance imaging (MRI) at 40 ms resolution for the simultaneous determination of blood flow in the ascending aorta (AA) and superior vena cava (SVC) in response to reduced intrathoracic pressure (Mueller manoeuvre). MATERIALS AND METHODS Through-plane flow was assessed in 20 healthy young subjects using real-time phase-contrast MRI based on highly undersampled radial fast low-angle shot (FLASH) with image reconstruction by regularized non-linear inversion. Haemodynamic alterations (three repetitions per subject = 60 events) were evaluated during normal breathing (10 s), inhalation with nearly closed epiglottis (10 s), and recovery (20 s). RESULTS Relative to normal breathing and despite interindividual differences, reduced intrathoracic pressure by at least 30 mmHg significantly decreased the initial peak mean velocity (averaged across the lumen) in the AA by -24 ± 9% and increased the velocity in the SVC by +28 ± 25% (p < 0.0001, n = 23 successful events). Respective changes in flow volume per heartbeat were -25 ± 9% in the AA and +49 ± 44% in the SVC (p < 0.0001, n = 23). Flow parameters returned to baseline during sustained pressure reduction, while the heart rate was elevated by 10% (p < 0.0001) after the start (n = 24) and end (n = 17) of the manoeuvre. CONCLUSIONS Real-time flow MRI during low intrathoracic pressure non-invasively revealed quantitative haemodynamic adjustments in both the AA and SVC.
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Affiliation(s)
- M Fasshauer
- Institute for Diagnostic and Interventional Radiology, Heart Centre, University Medical Centre, Georg-August-University Göttingen, Germany; DZHK, German Centre for Cardiovascular Research, Göttingen, Germany
| | - A A Joseph
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany; DZHK, German Centre for Cardiovascular Research, Göttingen, Germany
| | - J T Kowallick
- Institute for Diagnostic and Interventional Radiology, Heart Centre, University Medical Centre, Georg-August-University Göttingen, Germany; DZHK, German Centre for Cardiovascular Research, Göttingen, Germany
| | - C Unterberg-Buchwald
- Institute for Diagnostic and Interventional Radiology, Heart Centre, University Medical Centre, Georg-August-University Göttingen, Germany; Clinic for Cardiology and Pneumology, Heart Centre, University Medical Centre, Georg-August-University Göttingen, Germany; DZHK, German Centre for Cardiovascular Research, Göttingen, Germany
| | - K D Merboldt
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany; DZHK, German Centre for Cardiovascular Research, Göttingen, Germany
| | - D Voit
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany; DZHK, German Centre for Cardiovascular Research, Göttingen, Germany
| | - M Steinmetz
- DZHK, German Centre for Cardiovascular Research, Göttingen, Germany; Clinic for Paediatric Cardiology and Intensive Care Medicine, Heart Centre, University Medical Centre, Georg-August-University Göttingen, Germany
| | - W Staab
- Institute for Diagnostic and Interventional Radiology, Heart Centre, University Medical Centre, Georg-August-University Göttingen, Germany; DZHK, German Centre for Cardiovascular Research, Göttingen, Germany
| | - S Schaetz
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany; DZHK, German Centre for Cardiovascular Research, Göttingen, Germany
| | - S Zhang
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany; DZHK, German Centre for Cardiovascular Research, Göttingen, Germany
| | - J Frahm
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany; DZHK, German Centre for Cardiovascular Research, Göttingen, Germany
| | - J Lotz
- Institute for Diagnostic and Interventional Radiology, Heart Centre, University Medical Centre, Georg-August-University Göttingen, Germany; DZHK, German Centre for Cardiovascular Research, Göttingen, Germany.
| | - J M Sohns
- Institute for Diagnostic and Interventional Radiology, Heart Centre, University Medical Centre, Georg-August-University Göttingen, Germany; DZHK, German Centre for Cardiovascular Research, Göttingen, Germany
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Kowallick JT, Sohns JM, Unterberg-Buchwald C, Schulte C, Staab W, Merboldt KD, Voit D, Zhang S, Joseph AA, Frahm J, Lotz J. Hochauflösende Echtzeit-Cardio-MRT Flussmessung im Vergleich zur Cine Phasenkontrast-Flussmessung. ROFO-FORTSCHR RONTG 2013. [DOI: 10.1055/s-0033-1346231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Joseph AA, Merboldt KD, Voit D, Zhang S, Uecker M, Lotz J, Frahm J. Real-time phase-contrast MRI of cardiovascular blood flow using undersampled radial fast low-angle shot and nonlinear inverse reconstruction. NMR Biomed 2012; 25:917-924. [PMID: 22180216 DOI: 10.1002/nbm.1812] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Revised: 10/21/2011] [Accepted: 10/27/2011] [Indexed: 05/31/2023]
Abstract
Velocity-encoded phase-contrast MRI of cardiovascular blood flow commonly relies on electrocardiogram-synchronized cine acquisitions of multiple heartbeats to quantitatively determine the flow of an averaged cardiac cycle. Here, we present a new method for real-time phase-contrast MRI that combines flow-encoding gradients with highly undersampled radial fast low-angle shot acquisitions and phase-sensitive image reconstructions by regularized nonlinear inversion. Apart from calibration studies using steady and pulsatile flow, preliminary in vivo applications focused on through-plane flow in the ascending aorta of healthy subjects. With bipolar velocity-encoding gradients of alternating polarity that overlap the slice-refocusing gradient, the method yields flow-encoded images with an in-plane resolution of 1.8 mm, section thickness of 6 mm and measuring time at 3 T of 24 ms (TR/TE = 3.44/2.76 ms; flip angle, 10º; seven radial spokes per image). Accordingly, phase-contrast maps and corresponding velocity profiles achieve a temporal resolution of 48 ms. The evaluated peak velocities, stroke volumes, flow rates and respective variances over at least 20 consecutive heartbeats are in general agreement with literature data.
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Affiliation(s)
- Arun A Joseph
- Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany.
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Sohns JM, Joseph AA, Merboldt KD, Voit D, Zhang S, Uecker M, Lotz J, Frahm J. Quantitative Phasenkontrast-MRT der Aorta in Echtzeit: radiales FLASH mit Unterabtastung und nichtlinearer inverser Rekonstruktion. ROFO-FORTSCHR RONTG 2012. [DOI: 10.1055/s-0031-1300915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Ajjampur SSR, Koshy B, Venkataramani M, Sarkar R, Joseph AA, Jacob KS, Ward H, Kang G. Effect of cryptosporidial and giardial diarrhoea on social maturity, intelligence and physical growth in children in a semi-urban slum in south India. ACTA ACUST UNITED AC 2011; 31:205-12. [PMID: 21781414 DOI: 10.1179/1465328111y.0000000003] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Early childhood diarrhoea is a major cause of infant morbidity and mortality in developing countries. Recurrent and persistent diarrhoea affect growth and cognition in children as young as 6 years. OBJECTIVES To evaluate the effect of early childhood cryptosporidial and giardial diarrhoea on growth and development in children in a semi-urban slum in India. This is the first report of such assessment at 3 years of age. METHODS This study was undertaken on 116 children who were part of an ongoing birth cohort study (n=452) of rotaviral and cryptosporidial diarrhoea between June and December 2005. Social quotients (SQ) assessed by the Vineland Social Maturity Scale, intelligence quotients (IQ) assessed by the Seguin Form Board Test, physical growth parameters and sociodemographic data in 84 children with a history of cryptosporidial or giardial diarrhoea were compared with those of 32 without diarrhoea. RESULTS Children with a past history of giardial diarrhoea showed a trend towards lower SQ (p=0.09) and had significantly lower IQ (p=0.04) and increased wasting (p=0.04). Cryptosporidial diarrhoea was not associated with poor IQ, SQ or physical growth. CONCLUSION This study demonstrates the long-term effect of protozoan diarrhoea, especially that caused by giardia, on both intelligence and physical growth in Indian children as early as 3 years of age and re-inforces the need for early detection and prevention of early childhood protozoan diarrhoea.
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Affiliation(s)
- S S R Ajjampur
- Department of Gastrointestinal Sciences, Christian Medical College, Vellore, Tamil Nadu, India
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Joseph AA, Elbaum J, Cisneros GJ, Eisig SB. A cephalometric comparative study of the soft tissue airway dimensions in persons with hyperdivergent and normodivergent facial patterns. J Oral Maxillofac Surg 1998; 56:135-9; discussion 139-40. [PMID: 9461134 DOI: 10.1016/s0278-2391(98)90850-3] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE This study was performed to compare the dimensions of the nasopharynx, oropharnynx, and hypopharynx of persons with hyperdivergent and normodivergent facial types, and to determine whether any variations exist. PATIENTS AND METHODS Lateral cephalometric records of a population with a normodivergent facial pattern (n = 23) and a group with a hyperdivergent facial pattern (n = 27) as evidenced by increased mandibular plane angle were used to compare the soft tissue airway dimensions. Statistical analysis consisted of Student's t-tests, Wilcoxon rank sums, and chi2. Statistical significance was set .05. RESULTS Overall the hyperdivergent group had a narrower anteroposterior pharyngeal dimension than the normodivergent control group. This narrowing was specifically noted in the nasopharynx at the level of the hard palate and in the oropharynx at the level of the tip of the soft palate and the mandible. In addition, the posterior pharyngeal wall had a thinning at the level of the inferior border of the third cervical vertebrae, and there was a more obtuse palatal angle. The tongue was also positioned more inferiorly and posteriorly in the hyperdivergent group, as evidenced by the increased distance between the hyoid bone and the mandibular plane and the increased distance between the soft palate tip and the epiglottis. The hyperdivergent group had more retruded maxillary and mandibular apical bases and a higher Class II skeletal discrepancy. CONCLUSIONS The narrower anteroposterior dimension of the airway in hyperdivergent patients may be attributable to skeletal features common to such patients, that is, retrusion of the maxilla and the mandible and vertical maxillary excess. Other features, such as an obtuse soft palate and low-set hyoid, also may be contributory factors. The relatively thin posterior pharyngeal wall observed in hyperdivergent patients might be a compensatory mechanism.
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Affiliation(s)
- A A Joseph
- Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, NY, USA
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Abstract
Gender differences in disability constitute a fertile area of research, as disabilities need to be measured and evaluated in the social context which defines role expectations and consequently the role performance. This paper reports on the differences in disability in married patients with schizophrenia, as marital status is an important determinant of role expectation. The study sample constituted 30 married patients, of both sexes, who satisfied DSM-III criteria for schizophrenia, and were living with their spouse at the time of assessment. Disability was evaluated using the DAS (modified version). The findings indicated that women were more disabled than men on many of the evaluation parameters (p < 0.05); there was also a strong correlation between negative symptoms and disability variables in both the sexes. While a correlation between PSE syndromes and disability variables was seen in the case of males, the relationship was not seen in females. Stepwise regression also revealed that negative symptoms predominated among the factors associated with global disability in both sexes. Most of the reports in the literature reveal that women are less disabled than men. The findings of this study, that women are more disabled than men, is discussed in the context of the social conditions prevailing in India.
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Affiliation(s)
- R Shankar
- Schizophrenia Research Foundation, East Anna Nagar, Madras, India
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Thara R, Joseph AA. Gender differnces in symptoms and course of schizophrenia. Indian J Psychiatry 1995; 37:124-8. [PMID: 21743732 PMCID: PMC2971495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
This paper deals with gender differences in symptom pattern, course and (Usability in a cohort of 76 patients who were completely and prospectively followed up for a period often years. Both at inclusion and follow up, males had more of nuclear syndrome, but largely the differences were not statistically significant. Disability was more in the males, especially in the area of occupational functioning. The paper discusses gender based research in the Indian context.
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Affiliation(s)
- R Thara
- R. Thara, Schizophrenia Research Foundation, C-46, 13 A Street, East Anna Nagar, Madras 600102
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Joseph AA, Hill JL, Patel J, Patel S, Kincl FA. Sustained-release hormonal preparations XV: release of progesterone from cholesterol pellets in vivo. J Pharm Sci 1977; 66:490-3. [PMID: 856969 DOI: 10.1002/jps.2600660408] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Progesterone-sterol pellets were made that porvided a zero-order release of progesterone for 80 days. 4-(14)C-Progesterone was used to measure the release in vitro and in vivo. The dissolution rate in vitro (distilled water as the desorbing medium) for progesterone-cholesterol (59:41 w/w) and the progesterone-beta-sitosterol (47:53 w/w) pellets was 72 microng/100 mm2/24 hr. The average in vivo absorption from subcutaneously implanted pellets in rabbits was 2 +/- 0.1 microng/ml of plasma/cm2 of surface area. Of this amount, 20-25% was progesterone; the remainder was progesterone metabolites and conjugates. Zero-order release (plasma levels) was obtained for approximately 80 days or until about 70% of the available progesterone was exhausted. During this time, the level of excreted radioactivity in urine continuously decreased, indicating that monitoring only this parameter would lead to erroneous conclusions. A long-term effect and increased effectiveness were obtained with a 5-20-mg progesterone equivalent dose, using gel prepared from 2% methylcellulose as the suspending medium.
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Joseph AA, Kincl FA. Neonatal sterilization of rodents with steroid hormones. 5. A note on the influence of neonatal treatment with estradiol benzoate or testosterone propionate on steroid metabolism in the brain and testes of adult male rats. J Steroid Biochem 1974; 5:227-31. [PMID: 4853321 DOI: 10.1016/0022-4731(74)90136-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Joseph AA, Wixom RL. Amino acid metabolism in the genus Propionibacterium. Proc Soc Exp Biol Med 1972; 139:526-34. [PMID: 5059043 DOI: 10.3181/00379727-139-36179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Wixom RL, Heinemann MA, Semeraro RJ, Joseph AA. Studies in valine biosynthesis. IX. The enzymes in photosynthetic and autotrophic bacteria. Biochim Biophys Acta 1971; 244:532-46. [PMID: 5003668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Wixom RL, Joseph AA. Studies in valine biosynthesis. 8. Dihydroxyacid dehydratase activity in microorganisms with diverse fermentation patterns. Proc Soc Exp Biol Med 1971; 137:292-8. [PMID: 5581667 DOI: 10.3181/00379727-137-35563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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