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Slawig A, Rothe M, Deistung A, Bohndorf K, Brill R, Graf S, Weng AM, Wohlgemuth WA, Gussew A. Ultra-short echo time (UTE) MR imaging: A brief review on technical considerations and clinical applications. ROFO-FORTSCHR RONTG 2024; 196:671-681. [PMID: 37995735 DOI: 10.1055/a-2193-1379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2023]
Affiliation(s)
- Anne Slawig
- University Clinic and Outpatient Clinic for Radiology, University Hospital Halle, Germany
- Halle MR Imaging Core Facility, Medical faculty, Martin Luther University Halle Wittenberg, Halle, Germany
| | - Maik Rothe
- University Clinic and Outpatient Clinic for Radiology, University Hospital Halle, Germany
- Halle MR Imaging Core Facility, Medical faculty, Martin Luther University Halle Wittenberg, Halle, Germany
| | - Andreas Deistung
- University Clinic and Outpatient Clinic for Radiology, University Hospital Halle, Germany
- Halle MR Imaging Core Facility, Medical faculty, Martin Luther University Halle Wittenberg, Halle, Germany
| | - Klaus Bohndorf
- University Clinic and Outpatient Clinic for Radiology, University Hospital Halle, Germany
| | - Richard Brill
- University Clinic and Outpatient Clinic for Radiology, University Hospital Halle, Germany
| | - Simon Graf
- University Clinic and Outpatient Clinic for Radiology, University Hospital Halle, Germany
- Halle MR Imaging Core Facility, Medical faculty, Martin Luther University Halle Wittenberg, Halle, Germany
| | - Andreas Max Weng
- Department of Diagnostic and Interventional Radiology, University Hospital Wurzburg, Wurzburg, Germany
| | - Walter A Wohlgemuth
- University Clinic and Outpatient Clinic for Radiology, University Hospital Halle, Germany
- Halle MR Imaging Core Facility, Medical faculty, Martin Luther University Halle Wittenberg, Halle, Germany
| | - Alexander Gussew
- University Clinic and Outpatient Clinic for Radiology, University Hospital Halle, Germany
- Halle MR Imaging Core Facility, Medical faculty, Martin Luther University Halle Wittenberg, Halle, Germany
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Ma Y, Jang H, Jerban S, Chang EY, Chung CB, Bydder GM, Du J. Making the invisible visible-ultrashort echo time magnetic resonance imaging: Technical developments and applications. APPLIED PHYSICS REVIEWS 2022; 9:041303. [PMID: 36467869 PMCID: PMC9677812 DOI: 10.1063/5.0086459] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 09/12/2022] [Indexed: 05/25/2023]
Abstract
Magnetic resonance imaging (MRI) uses a large magnetic field and radio waves to generate images of tissues in the body. Conventional MRI techniques have been developed to image and quantify tissues and fluids with long transverse relaxation times (T2s), such as muscle, cartilage, liver, white matter, gray matter, spinal cord, and cerebrospinal fluid. However, the body also contains many tissues and tissue components such as the osteochondral junction, menisci, ligaments, tendons, bone, lung parenchyma, and myelin, which have short or ultrashort T2s. After radio frequency excitation, their transverse magnetizations typically decay to zero or near zero before the receiving mode is enabled for spatial encoding with conventional MR imaging. As a result, these tissues appear dark, and their MR properties are inaccessible. However, when ultrashort echo times (UTEs) are used, signals can be detected from these tissues before they decay to zero. This review summarizes recent technical developments in UTE MRI of tissues with short and ultrashort T2 relaxation times. A series of UTE MRI techniques for high-resolution morphological and quantitative imaging of these short-T2 tissues are discussed. Applications of UTE imaging in the musculoskeletal, nervous, respiratory, gastrointestinal, and cardiovascular systems of the body are included.
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Affiliation(s)
- Yajun Ma
- Department of Radiology, University of California, San Diego, California 92037, USA
| | - Hyungseok Jang
- Department of Radiology, University of California, San Diego, California 92037, USA
| | - Saeed Jerban
- Department of Radiology, University of California, San Diego, California 92037, USA
| | | | | | - Graeme M Bydder
- Department of Radiology, University of California, San Diego, California 92037, USA
| | - Jiang Du
- Author to whom correspondence should be addressed:. Tel.: (858) 246-2248, Fax: (858) 246-2221
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Kato Y, Ambale-Venkatesh B, Kassai Y, Kasuboski L, Schuijf J, Kapoor K, Caruthers S, Lima JAC. Non-contrast coronary magnetic resonance angiography: current frontiers and future horizons. MAGMA (NEW YORK, N.Y.) 2020; 33:591-612. [PMID: 32242282 PMCID: PMC7502041 DOI: 10.1007/s10334-020-00834-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 01/22/2020] [Accepted: 01/29/2020] [Indexed: 02/07/2023]
Abstract
Coronary magnetic resonance angiography (coronary MRA) is advantageous in its ability to assess coronary artery morphology and function without ionizing radiation or contrast media. However, technical limitations including reduced spatial resolution, long acquisition times, and low signal-to-noise ratios prevent it from clinical routine utilization. Nonetheless, each of these limitations can be specifically addressed by a combination of novel technologies including super-resolution imaging, compressed sensing, and deep-learning reconstruction. In this paper, we first review the current clinical use and motivations for non-contrast coronary MRA, discuss currently available coronary MRA techniques, and highlight current technical developments that hold unique potential to optimize coronary MRA image acquisition and post-processing. In the final section, we examine the various research-based coronary MRA methods and metrics that can be leveraged to assess coronary stenosis severity, physiological function, and atherosclerotic plaque characterization. We specifically discuss how such technologies may contribute to the clinical translation of coronary MRA into a robust modality for routine clinical use.
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Affiliation(s)
- Yoko Kato
- Division of Cardiology, Johns Hopkins University School of Medicine, 600 N Wolfe St, Blalock 524, Baltimore, MD, 21287-0409, USA
| | | | | | | | | | - Karan Kapoor
- Division of Cardiology, Johns Hopkins University School of Medicine, 600 N Wolfe St, Blalock 524, Baltimore, MD, 21287-0409, USA
| | | | - Joao A C Lima
- Division of Cardiology, Johns Hopkins University School of Medicine, 600 N Wolfe St, Blalock 524, Baltimore, MD, 21287-0409, USA.
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Weiger M, Pruessmann KP. Short-T 2 MRI: Principles and recent advances. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2019; 114-115:237-270. [PMID: 31779882 DOI: 10.1016/j.pnmrs.2019.07.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/14/2019] [Accepted: 07/26/2019] [Indexed: 06/10/2023]
Abstract
Among current modalities of biomedical and diagnostic imaging, MRI stands out by virtue of its versatile contrast obtained without ionizing radiation. However, in various cases, e.g., water protons in tissues such as bone, tendon, and lung, MRI performance is limited by the rapid decay of resonance signals associated with short transverse relaxation times T2 or T2*. Efforts to address this shortcoming have led to a variety of specialized short-T2 techniques. Recent progress in this field expands the choice of methods and prompts fresh considerations with regard to instrumentation, data acquisition, and signal processing. In this review, the current status of short-T2 MRI is surveyed. In an attempt to structure the growing range of techniques, the presentation highlights overarching concepts and basic methodological options. The most frequently used approaches are described in detail, including acquisition strategies, image reconstruction, hardware requirements, means of introducing contrast, sources of artifacts, limitations, and applications.
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Affiliation(s)
- Markus Weiger
- Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland.
| | - Klaas P Pruessmann
- Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
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Chiocchi M, Chiaravalloti A, Morosetti D, Loreni G, Gandini R, Mancino S, Fabiano S, Simonetti G. Virtual histology-intravascular ultrasound as a diagnostic alternative for morphological characterization of carotid plaque. J Cardiovasc Med (Hagerstown) 2019; 20:335-342. [DOI: 10.2459/jcm.0b013e328356a5d2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Superficial and multiple calcifications and ulceration associate with intraplaque hemorrhage in the carotid atherosclerotic plaque. Eur Radiol 2018; 28:4968-4977. [PMID: 29876705 PMCID: PMC6223859 DOI: 10.1007/s00330-018-5535-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Revised: 04/18/2018] [Accepted: 05/11/2018] [Indexed: 01/09/2023]
Abstract
Objective Intraplaque hemorrhage (IPH) and ulceration of carotid atherosclerotic plaques have been associated with vulnerability while calcification has been conventionally thought protective. However, studies suggested calcification size and location may increase plaque vulnerability. This study explored the association between calcium configurations and ulceration with IPH. Methods One hundred thirty-seven consecutive symptomatic patients scheduled for carotid endarterectomy were recruited. CTA and CTP were performed prior to surgery. Plaque samples were collected for histology. According to the location, calcifications were categorized into superficial, deep and mixed types; according to the size and number, calcifications were classified as thick and thin, multiple and single. Results Seventy-one plaques had IPH (51.8%) and 83 had ulceration (60.6%). The appearance of IPH and ulceration was correlated (r = 0.49; p < 0.001). The incidence of multiple, superficial and thin calcifications was significantly higher in lesions with IPH and ulceration compared with those without. After adjusting factors including age, stenosis and ulceration, the presence of calcification [OR (95% CI), 3.0 (1.1-8.2), p = 0.035], multiple calcification [3.9 (1.4-10.9), p = 0.009] and superficial calcification [3.4 (1.1-10.8), p = 0.001] were all associated with IPH. ROC analysis showed that the AUC of superficial and multiple calcifications in detecting IPH was 0.63 and 0.66, respectively (p < 0.05). When the ulceration was combined, AUC increased significantly to 0.82 and 0.83, respectively. Results also showed that patients with lesions of both ulceration and IPH have significantly reduced brain perfusion in the area ipsilateral to the infarction. Conclusions Superficial and multiple calcifications and ulceration were associated with carotid IPH, and they may be a surrogate for higher risk lesions. Key Points • CTA-defined superficial and multiple calcifications in carotid atherosclerotic plaques are independently associated with the presence of intraplaque hemorrhage. • The combination of superficial and multiple calcifications and ulceration is highly predictive of carotid intraplaque hemorrhage. • Patients with lesions of both ulceration and intraplaque hemorrhage have significantly reduced brain perfusion in the area ipsilateral to the infarction.
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Clinical Evaluation of Silent T1-Weighted MRI and Silent MR Angiography of the Brain. AJR Am J Roentgenol 2017; 210:404-411. [PMID: 29112472 DOI: 10.2214/ajr.17.18247] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE New MRI sequences based on rapid radial acquisition have reduced gradient noise. The purpose of this study was to compare Silent T1-weighted and unenhanced MR angiography (MRA) against conventional sequences in a clinical population. MATERIALS AND METHODS The study cohort consisted of 40 patients with suspected brain metastases (median age, 60 years; range, 23-91 years) who underwent T1-weighted contrast-enhanced MRI and 51 patients with suspected vascular lesions or cerebral ischemia (median age, 60 years; range, 16-94 years) who underwent unenhanced intracranial MRA. Three neuroradiologists reviewed the images blindly and rated several measures of image quality on a 5-point Likert scale. Reviewers recorded the number of enhancing lesions and whether Silent images were better than, worse than, or equivalent to conventional images. RESULTS For T1-weighted MR images, ratings were slightly lower for Silent versus conventional images, except for diagnostic confidence. Although more lesions were detected on conventional images, this difference was not statistically significant; agreement was seen in 88% of cases. In 48% of cases, T1-weighted scans were deemed equivalent, but when a preference existed, it was usually for conventional images (38% vs 14%). Conventional MRA images were rated higher on all image quality metrics and were strongly preferred (reviewers preferred conventional images in 69% of cases, rated the images as equivalent in 27% of cases, and preferred Silent images in 4% of cases). In some cases, artifacts on Silent images caused reduced vessel caliber, vessel irregularities, and even absent vessels. CONCLUSION Although conventional T1-weighted images were preferred overall, most Silent T1-weighted images were rated as equivalent to or better than conventional images and represent a potential alternative for imaging of noise-averse patients. Silent MRA scored significantly worse and could not be recommended at this time, suggesting that it requires additional refinement before routine clinical use.
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Hamamoto K, Chiba E, Matsuura K, Okochi T, Tanno K, Tanaka O. Ultra-short echo time magnetic resonance imaging for detection of pulmonary arteriovenous malformation recanalization after coil embolization: a case report and a phantom study. Acta Radiol Open 2017; 6:2058460117732101. [PMID: 28944082 PMCID: PMC5602216 DOI: 10.1177/2058460117732101] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Accepted: 08/27/2017] [Indexed: 11/29/2022] Open
Abstract
A pulmonary arteriovenous malformation (PAVM) is a direct connection between the pulmonary arteries and veins for which metallic coil transcatheter embolization is the standard of care. Detecting recanalization after PAVM treatment is crucial, but direct visualization with computed tomography or magnetic resonance imaging (MRI) is generally difficult. Here, we report a case of a recanalized PAVM that was directly detected with ultra-short echo time MRI. The detection of these signals in the coils was confirmed in a phantom study.
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Affiliation(s)
- Kohei Hamamoto
- Department of Radiology, Saitama Medical Center, Jichi Medical University, Saitama, Japan
| | - Emiko Chiba
- Department of Radiology, Saitama Medical Center, Jichi Medical University, Saitama, Japan
| | - Katsuhiko Matsuura
- Department of Radiology, Saitama Medical Center, Jichi Medical University, Saitama, Japan
| | - Tomohisa Okochi
- Department of Radiology, Saitama Medical Center, Jichi Medical University, Saitama, Japan
| | - Keisuke Tanno
- Department of Radiology, Saitama Medical Center, Jichi Medical University, Saitama, Japan
| | - Osamu Tanaka
- Department of Radiology, Saitama Medical Center, Jichi Medical University, Saitama, Japan
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Krämer M, Motaal AG, Herrmann KH, Löffler B, Reichenbach JR, Strijkers GJ, Hoerr V. Cardiac 4D phase-contrast CMR at 9.4 T using self-gated ultra-short echo time (UTE) imaging. J Cardiovasc Magn Reson 2017; 19:39. [PMID: 28359292 PMCID: PMC5374606 DOI: 10.1186/s12968-017-0351-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 03/02/2017] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Time resolved 4D phase contrast (PC) cardiovascular magnetic resonance (CMR) in mice is challenging due to long scan times, small animal ECG-gating and the rapid blood flow and cardiac motion of small rodents. To overcome several of these technical challenges we implemented a retrospectively self-gated 4D PC radial ultra-short echo-time (UTE) acquisition scheme and assessed its performance in healthy mice by comparing the results with those obtained with an ECG-triggered 4D PC fast low angle shot (FLASH) sequence. METHODS Cardiac 4D PC CMR images were acquired at 9.4 T in healthy mice using the proposed self-gated radial center-out UTE acquisition scheme (TE/TR of 0.5 ms/3.1 ms) and a standard Cartesian 4D PC imaging sequence (TE/TR of 2.1 ms/5.0 ms) with a four-point Hadamard flow encoding scheme. To validate the proposed UTE flow imaging technique, experiments on a flow phantom with variable pump rates were performed. RESULTS The anatomical images and flow velocity maps of the proposed 4D PC UTE technique showed reduced artifacts and an improved SNR (left ventricular cavity (LV): 8.9 ± 2.5, myocardium (MC): 15.7 ± 1.9) compared to those obtained using a typical Cartesian FLASH sequence (LV: 5.6 ± 1.2, MC: 10.1 ± 1.4) that was used as a reference. With both sequences comparable flow velocities were obtained in the flow phantom as well as in the ascending aorta (UTE: 132.8 ± 18.3 cm/s, FLASH: 134.7 ± 13.4 cm/s) and pulmonary artery (UTE: 78.5 ± 15.4 cm/s, FLASH: 86.6 ± 6.2 cm/s) of the animals. Self-gated navigator signals derived from information of the oversampled k-space center were successfully extracted for all animals with a higher gating efficiency of time spent on acquiring gated data versus total measurement time (UTE: 61.8 ± 11.5%, FLASH: 48.5 ± 4.9%). CONCLUSIONS The proposed self-gated 4D PC UTE sequence enables robust and accurate flow velocity mapping of the mouse heart in vivo at high magnetic fields. At the same time SNR, gating efficiency, flow artifacts and image quality all improved compared to the images obtained using the well-established, ECG-triggered, 4D PC FLASH sequence.
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Affiliation(s)
- M. Krämer
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital - Friedrich Schiller University Jena, Philosophenweg 3, D-07743 Jena, Germany
| | - A. G. Motaal
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands
| | - K-H. Herrmann
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital - Friedrich Schiller University Jena, Philosophenweg 3, D-07743 Jena, Germany
| | - B. Löffler
- Institute of Medical Microbiology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
| | - J. R. Reichenbach
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital - Friedrich Schiller University Jena, Philosophenweg 3, D-07743 Jena, Germany
- Michael Stifel Center for Data-driven and Simulation Science Jena, Friedrich Schiller University Jena, Jena, Germany
- Abbe School of Photonics, Friedrich Schiller University Jena, Jena, Germany
- Center of Medical Optics and Photonics, Friedrich Schiller University Jena, Jena, Germany
| | - G. J. Strijkers
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands
- Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, Netherlands
| | - V. Hoerr
- Institute of Medical Microbiology, Jena University Hospital, Friedrich Schiller University Jena, Jena, Germany
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Peyrou J, Cochet H, Salel M, Barandon L, Latrabe V, Corneloup O, Montaudon M, Laurent F, Dournes G. Characterization of calcification in constrictive pericarditis using an ultrashort echo time sequence. J Magn Reson Imaging 2016; 45:1854-1856. [PMID: 27862554 DOI: 10.1002/jmri.25552] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 10/27/2016] [Indexed: 11/10/2022] Open
Affiliation(s)
- Jérôme Peyrou
- Unité d'Imagerie Cardiothoracique, Centre Hospitalier Universitaire de Bordeaux, Pessac, France.,Laboratoire d'Echocardiographie, Centre Hospitalier Universitaire de Bordeaux, Pessac, France
| | - Hubert Cochet
- Unité d'Imagerie Cardiothoracique, Centre Hospitalier Universitaire de Bordeaux, Pessac, France.,Centre de Recherche Cardiothoracique de Bordeaux, Université de Bordeaux / Inserm U1045, France
| | - Marjorie Salel
- Unité d'Imagerie Cardiothoracique, Centre Hospitalier Universitaire de Bordeaux, Pessac, France
| | - Laurent Barandon
- Centre de Recherche Cardiothoracique de Bordeaux, Université de Bordeaux / Inserm U1045, France.,Service de Chirurgie Cardiaque, Centre Hospitalier Universitaire de Bordeaux, Pessac, France
| | - Valérie Latrabe
- Unité d'Imagerie Cardiothoracique, Centre Hospitalier Universitaire de Bordeaux, Pessac, France
| | - Olivier Corneloup
- Unité d'Imagerie Cardiothoracique, Centre Hospitalier Universitaire de Bordeaux, Pessac, France
| | - Michel Montaudon
- Unité d'Imagerie Cardiothoracique, Centre Hospitalier Universitaire de Bordeaux, Pessac, France.,Centre de Recherche Cardiothoracique de Bordeaux, Université de Bordeaux / Inserm U1045, France
| | - Frančois Laurent
- Unité d'Imagerie Cardiothoracique, Centre Hospitalier Universitaire de Bordeaux, Pessac, France.,Centre de Recherche Cardiothoracique de Bordeaux, Université de Bordeaux / Inserm U1045, France
| | - Gaël Dournes
- Unité d'Imagerie Cardiothoracique, Centre Hospitalier Universitaire de Bordeaux, Pessac, France.,Centre de Recherche Cardiothoracique de Bordeaux, Université de Bordeaux / Inserm U1045, France
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Herrmann KH, Krämer M, Reichenbach JR. Time Efficient 3D Radial UTE Sampling with Fully Automatic Delay Compensation on a Clinical 3T MR Scanner. PLoS One 2016; 11:e0150371. [PMID: 26975051 PMCID: PMC4790903 DOI: 10.1371/journal.pone.0150371] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 02/12/2016] [Indexed: 11/28/2022] Open
Abstract
This work’s aim was to minimize the acquisition time of a radial 3D ultra-short echo-time (UTE) sequence and to provide fully automated, gradient delay compensated, and therefore artifact free, reconstruction. The radial 3D UTE sequence (echo time 60 μs) was implemented as single echo acquisition with center-out readouts and improved time efficient spoiling on a clinical 3T scanner without hardware modifications. To assess the sequence parameter dependent gradient delays each acquisition contained a quick calibration scan and utilized the phase of the readouts to detect the actual k-space center. This calibration scan does not require any user interaction. To evaluate the robustness of this automatic delay estimation phantom experiments were performed and 19 in vivo imaging data of the head, tibial cortical bone, feet and lung were acquired from 6 volunteers. As clinical application of this fast 3D UTE acquisition single breath-hold lung imaging is demonstrated. The proposed sequence allowed very short repetition times (TR~1ms), thus reducing total acquisition time. The proposed, fully automated k-phase based gradient delay calibration resulted in accurate delay estimations (difference to manually determined optimal delay −0.13 ± 0.45 μs) and allowed unsupervised reconstruction of high quality images for both phantom and in vivo data. The employed fast spoiling scheme efficiently suppressed artifacts caused by incorrectly refocused echoes. The sequence proved to be quite insensitive to motion, flow and susceptibility artifacts and provides oversampling protection against aliasing foldovers in all directions. Due to the short TR, acquisition times are attractive for a wide range of clinical applications. For short T2* mapping this sequence provides free choice of the second TE, usually within less scan time as a comparable dual echo UTE sequence.
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Affiliation(s)
- Karl-Heinz Herrmann
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Martin Krämer
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
| | - Jürgen R Reichenbach
- Medical Physics Group, Institute of Diagnostic and Interventional Radiology, Jena University Hospital, Friedrich-Schiller-University Jena, Jena, Germany
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12
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Irie R, Suzuki M, Yamamoto M, Takano N, Suga Y, Hori M, Kamagata K, Takayama M, Yoshida M, Sato S, Hamasaki N, Oishi H, Aoki S. Assessing Blood Flow in an Intracranial Stent: A Feasibility Study of MR Angiography Using a Silent Scan after Stent-Assisted Coil Embolization for Anterior Circulation Aneurysms. AJNR Am J Neuroradiol 2014; 36:967-70. [PMID: 25523588 DOI: 10.3174/ajnr.a4199] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 10/29/2014] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Blood flow in an intracranial stent cannot be visualized with 3D time-of-flight MR angiography owing to magnetic susceptibility and radiofrequency shielding. As a novel follow-up tool after stent-assisted coil embolization, we applied MRA by using a Silent Scan algorithm that contains an ultrashort TE combined with an arterial spin-labeling technique (Silent MRA). The purpose of this study was to determine whether Silent MRA could visualize flow in an intracranial stent placed in the anterior circulation. MATERIALS AND METHODS Nine patients treated with stent-assisted coil embolization for anterior circulation aneurysms underwent MRAs (Silent MRA and TOF MRA) and x-ray digital subtraction angiography. MRAs were performed in the same session on a 3T unit. Two neuroradiologists independently reviewed the MRA images and subjectively scored flow in a stent as 1 (not visible) to 4 (excellent) by referring to the latest x-ray digital subtraction angiography image as a criterion standard. RESULTS Both observers gave MRA higher scores than TOF MRA for flow in a stent in all cases. The mean score for Silent MRA was 3.44 ± 0.53, and for TOF MRA, it was 1.44 ± 0.46 (P < .001). CONCLUSIONS Silent MRA was able to visualize flow in an intracranial stent more effectively than TOF MRA. Silent MRA might be useful for follow-up imaging after stent-assisted coil embolization, though these study results may be only preliminary due to some limitations.
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Affiliation(s)
- R Irie
- From the Departments of Radiology (R.I., M.S., N.T., M.H., K.K., M.T., M. Yoshida, S.S., N.H., S.A.)
| | - M Suzuki
- From the Departments of Radiology (R.I., M.S., N.T., M.H., K.K., M.T., M. Yoshida, S.S., N.H., S.A.)
| | - M Yamamoto
- Neurosurgery (M. Yamamoto, Y.S., H.O.), Juntendo University Hospital, Tokyo, Japan
| | - N Takano
- From the Departments of Radiology (R.I., M.S., N.T., M.H., K.K., M.T., M. Yoshida, S.S., N.H., S.A.)
| | - Y Suga
- Neurosurgery (M. Yamamoto, Y.S., H.O.), Juntendo University Hospital, Tokyo, Japan
| | - M Hori
- From the Departments of Radiology (R.I., M.S., N.T., M.H., K.K., M.T., M. Yoshida, S.S., N.H., S.A.)
| | - K Kamagata
- From the Departments of Radiology (R.I., M.S., N.T., M.H., K.K., M.T., M. Yoshida, S.S., N.H., S.A.)
| | - M Takayama
- From the Departments of Radiology (R.I., M.S., N.T., M.H., K.K., M.T., M. Yoshida, S.S., N.H., S.A.)
| | - M Yoshida
- From the Departments of Radiology (R.I., M.S., N.T., M.H., K.K., M.T., M. Yoshida, S.S., N.H., S.A.)
| | - S Sato
- From the Departments of Radiology (R.I., M.S., N.T., M.H., K.K., M.T., M. Yoshida, S.S., N.H., S.A.)
| | - N Hamasaki
- From the Departments of Radiology (R.I., M.S., N.T., M.H., K.K., M.T., M. Yoshida, S.S., N.H., S.A.)
| | - H Oishi
- Neurosurgery (M. Yamamoto, Y.S., H.O.), Juntendo University Hospital, Tokyo, Japan Department of Neuroendovascular Therapy (H.O.), Juntendo University School of Medicine, Tokyo, Japan
| | - S Aoki
- From the Departments of Radiology (R.I., M.S., N.T., M.H., K.K., M.T., M. Yoshida, S.S., N.H., S.A.)
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Du J, Peterson M, Kansal N, Bydder GM, Kahn A. Mineralization in calcified plaque is like that of cortical bone-Further evidence from ultrashort echo time (UTE) magnetic resonance imaging of carotid plaque calcification and cortical bone. Med Phys 2013; 40:102301. [DOI: 10.1118/1.4819944] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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14
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Károlyi M, Seifarth H, Liew G, Schlett CL, Maurovich-Horvat P, Stolzmann P, Dai G, Huang S, Goergen CJ, Nakano M, Otsuka F, Virmani R, Hoffmann U, Sosnovik DE. Classification of coronary atherosclerotic plaques ex vivo with T1, T2, and ultrashort echo time CMR. JACC Cardiovasc Imaging 2013; 6:466-74. [PMID: 23498670 PMCID: PMC3661771 DOI: 10.1016/j.jcmg.2012.09.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 09/04/2012] [Accepted: 09/06/2012] [Indexed: 11/23/2022]
Abstract
OBJECTIVES This study sought to determine whether the classification of human coronary atherosclerotic plaques with T1, T2, and ultrashort echo time (UTE) cardiac magnetic resonance (CMR) would correlate well with atherosclerotic plaque classification by histology. BACKGROUND CMR has been extensively used to classify carotid plaque, but its ability to characterize coronary plaque remains unknown. In addition, the detection of plaque calcification by CMR remains challenging. Here, we used T1, T2, and UTE CMR to evaluate atherosclerotic plaques in fixed post-mortem human coronary arteries. We hypothesized that the combination of T1, T2, and UTE CMR would allow both calcified and lipid-rich coronary plaques to be accurately detected. METHODS Twenty-eight plaques from human donor hearts with proven coronary artery disease were imaged at 9.4-T with a T1-weighted 3-dimensional fast low-angle shot (FLASH) sequence (250-μm resolution), a T2-weighted rapid acquisition with refocused echoes (RARE) sequence (in-plane resolution 0.156 mm), and an UTE sequence (300-μm resolution). Plaques showing selective hypointensity on T2-weighted CMR were classified as lipid-rich. Areas of hypointensity on the T1-weighted images, but not the UTE images, were classified as calcified. Hyperintensity on the T1-weighted and UTE images was classified as hemorrhage. Following CMR, histological characterization of the plaques was performed with a pentachrome stain and established American Heart Association criteria. RESULTS CMR showed high sensitivity and specificity for the detection of calcification (100% and 90%, respectively) and lipid-rich necrotic cores (90% and 75%, respectively). Only 2 lipid-rich foci were missed by CMR, both of which were extremely small. Overall, CMR-based classification of plaque was in complete agreement with the histological classification in 22 of 28 cases (weighted κ = 0.6945, p < 0.0001). CONCLUSIONS The utilization of UTE CMR allows plaque calcification in the coronary arteries to be robustly detected. High-resolution CMR with T1, T2, and UTE contrast enables accurate classification of human coronary atherosclerotic plaque.
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Affiliation(s)
- Mihály Károlyi
- Cardiac MR/PET/CT Program, Massachusetts General Hospital, Harvard Medical School, Boston, USA
| | - Harald Seifarth
- Cardiac MR/PET/CT Program, Massachusetts General Hospital, Harvard Medical School, Boston, USA
| | - Gary Liew
- Cardiac MR/PET/CT Program, Massachusetts General Hospital, Harvard Medical School, Boston, USA
| | - Christopher L. Schlett
- Cardiac MR/PET/CT Program, Massachusetts General Hospital, Harvard Medical School, Boston, USA
| | - Pál Maurovich-Horvat
- Cardiac MR/PET/CT Program, Massachusetts General Hospital, Harvard Medical School, Boston, USA
| | - Paul Stolzmann
- Cardiac MR/PET/CT Program, Massachusetts General Hospital, Harvard Medical School, Boston, USA
| | - Guangping Dai
- Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, USA
| | - Shuning Huang
- Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, USA
| | - Craig J. Goergen
- Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, USA
| | | | | | | | - Udo Hoffmann
- Cardiac MR/PET/CT Program, Massachusetts General Hospital, Harvard Medical School, Boston, USA
| | - David E. Sosnovik
- Cardiac MR/PET/CT Program, Massachusetts General Hospital, Harvard Medical School, Boston, USA
- Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, USA
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Pennell DJ, Carpenter JP, Firmin DN, Kilner PJ, Mohiaddin RH, Prasad SK. Review of Journal of Cardiovascular Magnetic Resonance 2011. J Cardiovasc Magn Reson 2012; 14:78. [PMID: 23158097 PMCID: PMC3519784 DOI: 10.1186/1532-429x-14-78] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Accepted: 11/08/2012] [Indexed: 12/15/2022] Open
Abstract
There were 83 articles published in the Journal of Cardiovascular Magnetic Resonance (JCMR) in 2011, which is an 11% increase in the number of articles since 2010. The quality of the submissions continues to increase. The editors had been delighted with the 2010 JCMR Impact Factor of 4.33, although this fell modestly to 3.72 for 2011. The impact factor undergoes natural variation according to citation rates of papers in the 2 years following publication, and is significantly influenced by highly cited papers such as official reports. However, we remain very pleased with the progress of the journal's impact over the last 5 years. Our acceptance rate is approximately 25%, and has been falling as the number of articles being submitted has been increasing. In accordance with Open-Access publishing, the JCMR articles go on-line as they are accepted with no collating of the articles into sections or special thematic issues. For this reason, the Editors feel it is useful to summarize the papers for the readership into broad areas of interest or theme, which we feel would be useful, so that areas of interest from the previous year can be reviewed in a single article in relation to each other and other recent JCMR articles. The papers are presented in broad themes and set in context with related literature and previously published JCMR papers to guide continuity of thought in the journal. We hope that you find the open-access system increases wider reading and citation of your papers, and that you will continue to send your quality manuscripts to JCMR for publication.
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Affiliation(s)
- Dudley J Pennell
- CMR Unit Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
- National Heart and Lung Institute, Imperial College, Exhibition Road, London, SW7 2AZ, UK
| | - John Paul Carpenter
- CMR Unit Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
- National Heart and Lung Institute, Imperial College, Exhibition Road, London, SW7 2AZ, UK
| | - David N Firmin
- CMR Unit Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
- National Heart and Lung Institute, Imperial College, Exhibition Road, London, SW7 2AZ, UK
| | - Philip J Kilner
- CMR Unit Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
- National Heart and Lung Institute, Imperial College, Exhibition Road, London, SW7 2AZ, UK
| | - Raad H Mohiaddin
- CMR Unit Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
- National Heart and Lung Institute, Imperial College, Exhibition Road, London, SW7 2AZ, UK
| | - Sanjay K Prasad
- CMR Unit Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
- National Heart and Lung Institute, Imperial College, Exhibition Road, London, SW7 2AZ, UK
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16
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Lehto LJ, Sierra A, Corum CA, Zhang J, Idiyatullin D, Pitkänen A, Garwood M, Gröhn O. Detection of calcifications in vivo and ex vivo after brain injury in rat using SWIFT. Neuroimage 2012; 61:761-72. [PMID: 22425671 DOI: 10.1016/j.neuroimage.2012.03.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Revised: 01/31/2012] [Accepted: 03/01/2012] [Indexed: 01/14/2023] Open
Abstract
Calcifications represent one component of pathology in many brain diseases. With MRI, they are most often detected by exploiting negative contrast in magnitude images. Calcifications are more diamagnetic than tissue, leading to a magnetic field disturbance that can be seen in phase MR images. Most phase imaging studies use gradient recalled echo based pulse sequences. Here, the phase component of SWIFT, a virtually zero acquisition delay sequence, was used to detect calcifications ex vivo and in vivo in rat models of status epilepticus and traumatic brain injury. Calcifications were detected in phase and imaginary SWIFT images based on their dipole like magnetic field disturbances. In magnitude SWIFT images, calcifications were distinguished as hypointense and hyperintense. Hypointense calcifications showed large crystallized granules with few surrounding inflammatory cells, while hyperintense calcifications contained small granules with the presence of more inflammatory cells. The size of the calcifications in SWIFT magnitude images correlated with that in Alizarin stained histological sections. Our data indicate that SWIFT is likely to better preserve signal in the proximity of a calcification or other field perturber in comparison to gradient echo due to its short acquisition delay and broad excitation bandwidth. Furthermore, a quantitative description for the phase contrast near dipole magnetic field inhomogeneities for the SWIFT pulse sequence is given. In vivo detection of calcifications provides a tool to probe the progression of pathology in neurodegenerative diseases. In particular, it appears to provide a surrogate marker for inflammatory cells around the calcifications after brain injury.
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Affiliation(s)
- Lauri Juhani Lehto
- Department of Neurobiology, Biomedical Imaging Unit, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
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Li C, Magland JF, Rad HS, Song HK, Wehrli FW. Comparison of optimized soft-tissue suppression schemes for ultrashort echo time MRI. Magn Reson Med 2011; 68:680-9. [PMID: 22161636 DOI: 10.1002/mrm.23267] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Revised: 09/29/2011] [Accepted: 10/03/2011] [Indexed: 12/21/2022]
Abstract
Ultrashort echo time (UTE) imaging with soft-tissue suppression reveals short-T(2) components (typically hundreds of microseconds to milliseconds) ordinarily not captured or obscured by long-T(2) tissue signals on the order of tens of milliseconds or longer. Therefore, the technique enables visualization and quantification of short-T(2) proton signals such as those in highly collagenated connective tissues. This work compares the performance of the three most commonly used long-T(2) suppression UTE sequences, i.e., echo subtraction (dual-echo UTE), saturation via dual-band saturation pulses (dual-band UTE), and inversion by adiabatic inversion pulses (IR-UTE) at 3 T, via Bloch simulations and experimentally in vivo in the lower extremities of test subjects. For unbiased performance comparison, the acquisition parameters are optimized individually for each sequence to maximize short-T(2) signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) between short- and long-T(2) components. Results show excellent short-T(2) contrast which is achieved with these optimized sequences. A combination of dual-band UTE with dual-echo UTE provides good short-T(2) SNR and CNR with less sensitivity to B(1) homogeneity. IR-UTE has the lowest short-T(2) SNR efficiency but provides highly uniform short-T(2) contrast and is well suited for imaging short-T(2) species with relatively short T(1) such as bone water.
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Affiliation(s)
- Cheng Li
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
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18
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Bydder GM. Review. The Agfa Mayneord lecture: MRI of short and ultrashort T₂ and T₂* components of tissues, fluids and materials using clinical systems. Br J Radiol 2011; 84:1067-82. [PMID: 22101579 PMCID: PMC3473831 DOI: 10.1259/bjr/74368403] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Revised: 04/29/2011] [Accepted: 06/30/2011] [Indexed: 11/05/2022] Open
Abstract
A variety of techniques are now available to directly or indirectly detect signal from tissues, fluids and materials that have short, ultrashort or supershort T₂ or T₂* components. There are also methods of developing image contrast between tissues and fluids in the short T₂ or T₂* range that can provide visualisation of anatomy, which has not been previously seen with MRI. Magnetisation transfer methods can now be applied to previously invisible tissues, providing indirect access to supershort T₂ components. Particular methods have been developed to target susceptibility effects and quantify them after correcting for anatomical distortion. Specific methods have also been developed to image the effects of magnetic iron oxide particles with positive contrast. Major advances have been made in techniques designed to correct for loss of signal and gross image distortion near metal. These methods are likely to substantially increase the range of application for MRI.
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Affiliation(s)
- G M Bydder
- Department of Radiology, University of California San Diego, San Diego, CA 92103-8226, USA.
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Pennell DJ, Firmin DN, Kilner PJ, Manning WJ, Mohiaddin RH, Prasad SK. Review of journal of cardiovascular magnetic resonance 2010. J Cardiovasc Magn Reson 2011; 13:48. [PMID: 21914185 PMCID: PMC3182946 DOI: 10.1186/1532-429x-13-48] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Accepted: 09/13/2011] [Indexed: 12/15/2022] Open
Abstract
There were 75 articles published in the Journal of Cardiovascular Magnetic Resonance (JCMR) in 2010, which is a 34% increase in the number of articles since 2009. The quality of the submissions continues to increase, and the editors were delighted with the recent announcement of the JCMR Impact Factor of 4.33 which showed a 90% increase since last year. Our acceptance rate is approximately 30%, but has been falling as the number of articles being submitted has been increasing. In accordance with Open-Access publishing, the JCMR articles go on-line as they are accepted with no collating of the articles into sections or special thematic issues. Last year for the first time, the Editors summarized the papers for the readership into broad areas of interest or theme, which we felt would be useful to practitioners of cardiovascular magnetic resonance (CMR) so that you could review areas of interest from the previous year in a single article in relation to each other and other recent JCMR articles 1. This experiment proved very popular with a very high rate of downloading, and therefore we intend to continue this review annually. The papers are presented in themes and comparison is drawn with previously published JCMR papers to identify the continuity of thought and publication in the journal. We hope that you find the open-access system increases wider reading and citation of your papers, and that you will continue to send your quality manuscripts to JCMR for publication.
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Affiliation(s)
- Dudley J Pennell
- CMR Unit Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK
- National Heart and Lung Institute, Imperial College, Exhibition Road, London, SW7 2AZ, UK
| | - David N Firmin
- CMR Unit Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK
- National Heart and Lung Institute, Imperial College, Exhibition Road, London, SW7 2AZ, UK
| | - Philip J Kilner
- CMR Unit Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK
- National Heart and Lung Institute, Imperial College, Exhibition Road, London, SW7 2AZ, UK
| | - Warren J Manning
- Department of Medicine (Cardiovascular Division) and Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215 USA
- Harvard Medical School, 25 Shattuck Street, Boston, MA 02115 USA
| | - Raad H Mohiaddin
- CMR Unit Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK
- National Heart and Lung Institute, Imperial College, Exhibition Road, London, SW7 2AZ, UK
| | - Sanjay K Prasad
- CMR Unit Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK
- National Heart and Lung Institute, Imperial College, Exhibition Road, London, SW7 2AZ, UK
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