{"title":"自由呼吸半径向双回波平衡稳态自由进动胸椎成像与摆动阿基米德螺旋极轨迹","authors":"Oliver Bieri , Orso Pusterla , Grzegorz Bauman","doi":"10.1016/j.zemedi.2022.01.003","DOIUrl":null,"url":null,"abstract":"<div><h3>Purpose</h3><p>To demonstrate free-breathing thoracic MRI with a minimal-TR balanced steady-state free precession (bSSFP) technique using wobbling Archimedean spiral pole (WASP) trajectories.</p></div><div><h3>Methods</h3><p>Phantom and free-breathing <em>in vivo</em> chest imaging in healthy volunteers was performed at 1.5T with a half-radial, dual-echo, bSSFP sequence, termed bSTAR. For maximum sampling efficiency, a single analog-to-digital converter window along the full bipolar readout was used. To ensure a homogeneous coverage of the k-space over multiple breathing cycles, radial k-space sampling followed short-duration Archimedean spiral interleaves that were randomly titled by a small polar angle and rotated by a golden angle about the polar axis; depticting a wobbling Archimedean spiral pole (WASP) trajectory. In phantom and <em>in vivo</em> experiments, WASP trajectories were compared to spiral phyllotaxis sampling in terms of eddy currents and were used to generate <em>in vivo</em> thorax images at different respiratory phases.</p></div><div><h3>Results</h3><p>WASP trajectories provided artifact-free bSTAR imaging in both phantom and <em>in vivo</em> and respiratory self-gated reconstruction was successfully performed in all subjects. The amount of the acquired data allowed the reconstruction of 10 volumes at different respiratory levels with isotropic resolution of 1.77<!--> <!-->mm from a scan of 5.5<!--> <!-->minutes (using a TR of 1.32ms), and one high-resolution 1.16<!--> <!-->mm end-expiratory volume from a scan of 4.7<!--> <!-->minutes (using a TR of 1.42ms). The very short TR of bSTAR mitigated off-resonance artifacts despite the large field-of-view.</p></div><div><h3>Conclusion</h3><p>We have demonstrated the feasibility of high-resolution free-breathing thoracic imaging with bSTAR using the wobbling Archimedean spiral pole in healthy subjects at 1.5T.</p></div>","PeriodicalId":54397,"journal":{"name":"Zeitschrift fur Medizinische Physik","volume":null,"pages":null},"PeriodicalIF":2.4000,"publicationDate":"2023-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10311259/pdf/","citationCount":"3","resultStr":"{\"title\":\"Free-breathing half-radial dual-echo balanced steady-state free precession thoracic imaging with wobbling Archimedean spiral pole trajectories\",\"authors\":\"Oliver Bieri , Orso Pusterla , Grzegorz Bauman\",\"doi\":\"10.1016/j.zemedi.2022.01.003\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><h3>Purpose</h3><p>To demonstrate free-breathing thoracic MRI with a minimal-TR balanced steady-state free precession (bSSFP) technique using wobbling Archimedean spiral pole (WASP) trajectories.</p></div><div><h3>Methods</h3><p>Phantom and free-breathing <em>in vivo</em> chest imaging in healthy volunteers was performed at 1.5T with a half-radial, dual-echo, bSSFP sequence, termed bSTAR. For maximum sampling efficiency, a single analog-to-digital converter window along the full bipolar readout was used. To ensure a homogeneous coverage of the k-space over multiple breathing cycles, radial k-space sampling followed short-duration Archimedean spiral interleaves that were randomly titled by a small polar angle and rotated by a golden angle about the polar axis; depticting a wobbling Archimedean spiral pole (WASP) trajectory. In phantom and <em>in vivo</em> experiments, WASP trajectories were compared to spiral phyllotaxis sampling in terms of eddy currents and were used to generate <em>in vivo</em> thorax images at different respiratory phases.</p></div><div><h3>Results</h3><p>WASP trajectories provided artifact-free bSTAR imaging in both phantom and <em>in vivo</em> and respiratory self-gated reconstruction was successfully performed in all subjects. The amount of the acquired data allowed the reconstruction of 10 volumes at different respiratory levels with isotropic resolution of 1.77<!--> <!-->mm from a scan of 5.5<!--> <!-->minutes (using a TR of 1.32ms), and one high-resolution 1.16<!--> <!-->mm end-expiratory volume from a scan of 4.7<!--> <!-->minutes (using a TR of 1.42ms). The very short TR of bSTAR mitigated off-resonance artifacts despite the large field-of-view.</p></div><div><h3>Conclusion</h3><p>We have demonstrated the feasibility of high-resolution free-breathing thoracic imaging with bSTAR using the wobbling Archimedean spiral pole in healthy subjects at 1.5T.</p></div>\",\"PeriodicalId\":54397,\"journal\":{\"name\":\"Zeitschrift fur Medizinische Physik\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.4000,\"publicationDate\":\"2023-05-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10311259/pdf/\",\"citationCount\":\"3\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Zeitschrift fur Medizinische Physik\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0939388922000034\",\"RegionNum\":4,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Zeitschrift fur Medizinische Physik","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0939388922000034","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING","Score":null,"Total":0}
Free-breathing half-radial dual-echo balanced steady-state free precession thoracic imaging with wobbling Archimedean spiral pole trajectories
Purpose
To demonstrate free-breathing thoracic MRI with a minimal-TR balanced steady-state free precession (bSSFP) technique using wobbling Archimedean spiral pole (WASP) trajectories.
Methods
Phantom and free-breathing in vivo chest imaging in healthy volunteers was performed at 1.5T with a half-radial, dual-echo, bSSFP sequence, termed bSTAR. For maximum sampling efficiency, a single analog-to-digital converter window along the full bipolar readout was used. To ensure a homogeneous coverage of the k-space over multiple breathing cycles, radial k-space sampling followed short-duration Archimedean spiral interleaves that were randomly titled by a small polar angle and rotated by a golden angle about the polar axis; depticting a wobbling Archimedean spiral pole (WASP) trajectory. In phantom and in vivo experiments, WASP trajectories were compared to spiral phyllotaxis sampling in terms of eddy currents and were used to generate in vivo thorax images at different respiratory phases.
Results
WASP trajectories provided artifact-free bSTAR imaging in both phantom and in vivo and respiratory self-gated reconstruction was successfully performed in all subjects. The amount of the acquired data allowed the reconstruction of 10 volumes at different respiratory levels with isotropic resolution of 1.77 mm from a scan of 5.5 minutes (using a TR of 1.32ms), and one high-resolution 1.16 mm end-expiratory volume from a scan of 4.7 minutes (using a TR of 1.42ms). The very short TR of bSTAR mitigated off-resonance artifacts despite the large field-of-view.
Conclusion
We have demonstrated the feasibility of high-resolution free-breathing thoracic imaging with bSTAR using the wobbling Archimedean spiral pole in healthy subjects at 1.5T.
期刊介绍:
Zeitschrift fur Medizinische Physik (Journal of Medical Physics) is an official organ of the German and Austrian Society of Medical Physic and the Swiss Society of Radiobiology and Medical Physics.The Journal is a platform for basic research and practical applications of physical procedures in medical diagnostics and therapy. The articles are reviewed following international standards of peer reviewing.
Focuses of the articles are:
-Biophysical methods in radiation therapy and nuclear medicine
-Dosimetry and radiation protection
-Radiological diagnostics and quality assurance
-Modern imaging techniques, such as computed tomography, magnetic resonance imaging, positron emission tomography
-Ultrasonography diagnostics, application of laser and UV rays
-Electronic processing of biosignals
-Artificial intelligence and machine learning in medical physics
In the Journal, the latest scientific insights find their expression in the form of original articles, reviews, technical communications, and information for the clinical practice.