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Özütemiz C. Cerebrovascular Imaging at 7T: A New High. Semin Roentgenol 2024; 59:148-156. [PMID: 38880513 DOI: 10.1053/j.ro.2024.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 01/30/2024] [Accepted: 01/31/2024] [Indexed: 06/18/2024]
Affiliation(s)
- Can Özütemiz
- University of Minnesota, Department of Radiology, MMC 292, 420 Delaware St. SE Minneapolis, MN.
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2
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Radojewski P, Dobrocky T, Branca M, Almiri W, Correia M, Raabe A, Bervini D, Gralla J, Wiest R, Mordasini P. Diagnosis of Small Unruptured Intracranial Aneurysms : Comparison of 7 T versus 3 T MRI. Clin Neuroradiol 2024; 34:45-49. [PMID: 37000197 PMCID: PMC10881608 DOI: 10.1007/s00062-023-01282-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 02/13/2023] [Indexed: 04/01/2023]
Abstract
PURPOSE Differentiating normal anatomical variants such as an infundibulum or a vascular loop from true intracranial aneurysms is crucial for patient management. We hypothesize that high-resolution 7 T magnetic resonance imaging (MRI) improves the detection and characterization of normal anatomical variants that may otherwise be misdiagnosed as small unruptured aneurysms. METHODS This is a retrospective, single-center study. All patients were scanned on a clinically approved 7 T MRI scanner and on a 3 T scanner. Image analysis was performed independently by three neuroradiologists blinded to clinical information. The presence of an unruptured intracranial aneurysm (UIA) and level of diagnostic certainty were assessed and the interrater agreement was calculated. If an aneurysm was present, the anatomic location and shape were recorded and compared. RESULTS In total, 53 patients with equivocal cerebrovascular findings on 1.5 T or 3 T MRI referred for a 7T MRI examination were included. Aneurysms were suspected in 42 patients examined at 3 T and in 23 patients at 7 T (rate difference 36%, 95% confidence interval, CI, 19-53%, p-value < 0.001). Major disagreement between the field strengths was observed in the A1 segment of anterior cerebral artery/anterior communicating artery (A1/ACOM) complex. The interrater agreement among the readers on the presence of an aneurysm on 7 T MRI was higher than that for 3 T MRI (0.925, 95% CI 0.866-0.983 vs. 0.786, 95% CI 0.700-0.873). CONCLUSION Our analysis demonstrates a significantly higher interrater agreement and improved diagnostic certainty when small intracranial aneurysms are visualized on 7 T MRI compared to 3 T. In a selected patient cohort, clinical implementation of 7 T MRI may help to establish the definitive diagnosis and thus have a beneficial impact on patient management.
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Affiliation(s)
- Piotr Radojewski
- Institute of Diagnostic and Interventional Neuroradiology, Bern University Hospital, Inselspital, University of Bern, Freiburgstrasse 18, 3010, Bern, Switzerland.
- Translational Imaging Center, sitem-insel, Bern, Switzerland.
| | - Tomas Dobrocky
- Institute of Diagnostic and Interventional Neuroradiology, Bern University Hospital, Inselspital, University of Bern, Freiburgstrasse 18, 3010, Bern, Switzerland
| | | | - William Almiri
- Institute of Diagnostic and Interventional Neuroradiology, Bern University Hospital, Inselspital, University of Bern, Freiburgstrasse 18, 3010, Bern, Switzerland
| | - Manuel Correia
- Institute of Diagnostic and Interventional Neuroradiology, Bern University Hospital, Inselspital, University of Bern, Freiburgstrasse 18, 3010, Bern, Switzerland
- Hospital de Santa Maria-Centro Hospitalar Lisboa Norte, Lisbon, Portugal
| | - Andreas Raabe
- Department of Neurosurgery, Bern University Hospital, Inselspital, University of Bern, Bern, Switzerland
| | - David Bervini
- Department of Neurosurgery, Bern University Hospital, Inselspital, University of Bern, Bern, Switzerland
| | - Jan Gralla
- Institute of Diagnostic and Interventional Neuroradiology, Bern University Hospital, Inselspital, University of Bern, Freiburgstrasse 18, 3010, Bern, Switzerland
| | - Roland Wiest
- Institute of Diagnostic and Interventional Neuroradiology, Bern University Hospital, Inselspital, University of Bern, Freiburgstrasse 18, 3010, Bern, Switzerland
- Translational Imaging Center, sitem-insel, Bern, Switzerland
| | - Pasquale Mordasini
- Institute of Diagnostic and Interventional Neuroradiology, Bern University Hospital, Inselspital, University of Bern, Freiburgstrasse 18, 3010, Bern, Switzerland
- Netzwerk Radiologie, Kantonsspital St. Gallen, St. Gallen, Switzerland
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3
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Özütemiz C, White M, Elvendahl W, Eryaman Y, Marjańska M, Metzger GJ, Patriat R, Kulesa J, Harel N, Watanabe Y, Grant A, Genovese G, Cayci Z. Use of a Commercial 7-T MRI Scanner for Clinical Brain Imaging: Indications, Protocols, Challenges, and Solutions-A Single-Center Experience. AJR Am J Roentgenol 2023; 221:788-804. [PMID: 37377363 PMCID: PMC10825876 DOI: 10.2214/ajr.23.29342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2023]
Abstract
The first commercially available 7-T MRI scanner (Magnetom Terra) was approved by the FDA in 2017 for clinical imaging of the brain and knee. After initial protocol development and sequence optimization efforts in volunteers, the 7-T system, in combination with an FDA-approved 1-channel transmit/32-channel receive array head coil, can now be routinely used for clinical brain MRI examinations. The ultrahigh field strength of 7-T MRI has the advantages of improved spatial resolution, increased SNR, and increased CNR but also introduces an array of new technical challenges. The purpose of this article is to describe an institutional experience with the use of the commercially available 7-T MRI scanner for routine clinical brain imaging. Specific clinical indications for which 7-T MRI may be useful for brain imaging include brain tumor evaluation with possible perfusion imaging and/or spectroscopy, radiotherapy planning; evaluation of multiple sclerosis and other demyelinating diseases, evaluation of Parkinson disease and guidance of deep brain stimulator placement, high-detail intracranial MRA and vessel wall imaging, evaluation of pituitary pathology, and evaluation of epilepsy. Detailed protocols, including sequence parameters, for these various indications are presented, and implementation challenges (including artifacts, safety, and side effects) and potential solutions are explored.
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Affiliation(s)
- Can Özütemiz
- Department of Radiology, University of Minnesota, 420 Delaware St SE, MMC 292, Minneapolis, MN 55455
| | - Matthew White
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN
- Center for Clinical Imaging Research, Department of Radiology, University of Minnesota, Minneapolis, MN
| | - Wendy Elvendahl
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN
- Center for Clinical Imaging Research, Department of Radiology, University of Minnesota, Minneapolis, MN
| | - Yigitcan Eryaman
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN
| | - Małgorzata Marjańska
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN
| | - Gregory J Metzger
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN
| | - Rémi Patriat
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN
| | - Jeramy Kulesa
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN
| | - Noam Harel
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN
| | - Yoichi Watanabe
- Department of Radiation Oncology, University of Minnesota, Minneapolis, MN
| | - Andrea Grant
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN
| | - Guglielmo Genovese
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN
| | - Zuzan Cayci
- Department of Radiology, University of Minnesota, 420 Delaware St SE, MMC 292, Minneapolis, MN 55455
- Center for Clinical Imaging Research, Department of Radiology, University of Minnesota, Minneapolis, MN
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4
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Lakhani DA, Zhou X, Tao S, Westerhold EM, Eidelman BH, Singh Sandhu SJ, Middlebrooks EH. Clinical application of ultra-high resolution compressed sensing time-of-flight MR angiography at 7T to detect small vessel pathology. Neuroradiol J 2023; 36:335-340. [PMID: 36173305 PMCID: PMC10268099 DOI: 10.1177/19714009221129576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
3D time-of-flight (TOF) MR angiography (MRA) benefits from ultra-high-field MRI (≥7 T) due to improved contrast and increased signal-to-noise ratio. However, high-resolution TOF MRA at 7T usually requires longer acquisition times. In addition, relatively higher specific absorption rate (SAR) at 7T limits the choice of optimal pulse sequence parameters, especially if venous saturation is employed. Here, we illustrate the clinical application of ultra-high resolution cerebral 7T TOF MRA using compressed sensing in cases of artery of Percheron and lacunar infarcts, which showed superior resolution and exquisite details pertinent to the clinical diagnosis. The technical challenges associated with high-resolution 7T imaging were alleviated by optimization of sequence parameters and utilization of compressed sensing acceleration.
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Affiliation(s)
- Dhairya A Lakhani
- Department of Radiology, West Virginia University, Morgantown, WV, USA
- Department of Radiology, Mayo Clinic, Jacksonville, FL, USA
| | - Xiangzhi Zhou
- Department of Radiology, Mayo Clinic, Jacksonville, FL, USA
| | - Shengzhen Tao
- Department of Radiology, Mayo Clinic, Jacksonville, FL, USA
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5
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Cervelli R, Cencini M, Cacciato Insilla A, Aringhieri G, Boggi U, Campani D, Tosetti M, Crocetti L. Ex-vivo human pancreatic specimen evaluation by 7 Tesla MRI: a prospective radiological-pathological correlation study. Radiol Med 2022; 127:950-959. [DOI: 10.1007/s11547-022-01533-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 07/25/2022] [Indexed: 10/15/2022]
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6
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Tsutsui S, Matsuda T, Takeda K, Sasaki M, Kubo Y, Setta K, Fujiwara S, Chida K, Ogasawara K. Assessment of Heating on Titanium Alloy Cerebral Aneurysm Clips during 7T MRI. AJNR Am J Neuroradiol 2022; 43:972-977. [PMID: 35738672 DOI: 10.3174/ajnr.a7561] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 05/06/2022] [Indexed: 12/15/2022]
Abstract
BACKGROUND AND PURPOSE Patients with cerebral aneurysms often undergo MR imaging after microsurgical clipping. Ultra-high-field MR imaging at 7T may provide high diagnostic capability in such clinical situations. However, titanium alloy clips have safety issues such as adverse interactions with static magnetic fields and radiofrequency-induced heating during 7T MR imaging. The purpose of this study was to quantitatively assess temperature increases on various types of titanium alloy aneurysm clips during 7T MR imaging. MATERIALS AND METHODS Five types of titanium alloy aneurysm clips were tested, including combinations of short, long, straight, angled, and fenestrated types. Each clip was set in a phantom filled with gelled saline mixed with polyacrylic acid and underwent 7T MR imaging with 3D T1WI with a spoiled gradient recalled acquisition in the steady-state technique. Temperature was chronologically measured at the tips of the clip blade and head, angled part of the clip, and 5 mm from the tip of the clip head using MR imaging-compatible fiber-optic thermometers. RESULTS Temperature increases at all locations for right-angled and short straight clips were <1°C. Temperature increases at the angled part for the 45° angled clip and the tip of the clip head for the straight fenestrated clip were >1°C. Temperature increases at all locations for the long straight clip were >2°C. CONCLUSIONS Temperature increases on the right-angled and short straight clips remained below the regulatory limit during 7T MR imaging, but temperature increases on the 45° angled, straight fenestrated, and long straight clips exceeded this limit.
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Affiliation(s)
- S Tsutsui
- From the Department of Neurosurgery (S.T., Y.K., K.S., S.F., K.C., K.O.)
| | - T Matsuda
- Division of Ultrahigh Field MRI (T.M., K.T., M.S.), Institute for Biomedical Sciences, Iwate Medical University School of Medicine, Morioka, Japan
| | - K Takeda
- Division of Ultrahigh Field MRI (T.M., K.T., M.S.), Institute for Biomedical Sciences, Iwate Medical University School of Medicine, Morioka, Japan
| | - M Sasaki
- Division of Ultrahigh Field MRI (T.M., K.T., M.S.), Institute for Biomedical Sciences, Iwate Medical University School of Medicine, Morioka, Japan
| | - Y Kubo
- From the Department of Neurosurgery (S.T., Y.K., K.S., S.F., K.C., K.O.)
| | - K Setta
- From the Department of Neurosurgery (S.T., Y.K., K.S., S.F., K.C., K.O.)
| | - S Fujiwara
- From the Department of Neurosurgery (S.T., Y.K., K.S., S.F., K.C., K.O.)
| | - K Chida
- From the Department of Neurosurgery (S.T., Y.K., K.S., S.F., K.C., K.O.)
| | - K Ogasawara
- From the Department of Neurosurgery (S.T., Y.K., K.S., S.F., K.C., K.O.)
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7
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Maupu C, Lebas H, Boulaftali Y. Imaging Modalities for Intracranial Aneurysm: More Than Meets the Eye. Front Cardiovasc Med 2022; 9:793072. [PMID: 35242823 PMCID: PMC8885801 DOI: 10.3389/fcvm.2022.793072] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 01/17/2022] [Indexed: 11/21/2022] Open
Abstract
Intracranial aneurysms (IA) are often asymptomatic and have a prevalence of 3 to 5% in the adult population. The risk of IA rupture is low, however when it occurs half of the patients dies from subarachnoid hemorrhage (SAH). To avoid this fatal evolution, the main treatment is an invasive surgical procedure, which is considered to be at high risk of rupture. This risk score of IA rupture is evaluated mainly according to its size and location. Therefore, angiography and anatomic imaging of the intracranial aneurysm are crucial for its diagnosis. Moreover, it has become obvious in recent years that several other factors are implied in this complication, such as the blood flow complexity or inflammation. These recent findings lead to the development of new IA imaging tools such as vessel wall imaging, 4D-MRI, or molecular MRI to visualize inflammation at the site of IA in human and animal models. In this review, we will summarize IA imaging techniques used for the patients and those currently in development.
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8
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Radojewski P, Slotboom J, Joseph A, Wiest R, Mordasini P. Clinical Implementation of 7T MRI for the Identification of Incidental Intracranial Aneurysms versus Anatomic Variants. AJNR Am J Neuroradiol 2021; 42:2172-2174. [PMID: 34711553 DOI: 10.3174/ajnr.a7331] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 08/30/2021] [Indexed: 11/07/2022]
Abstract
Most unruptured intracranial aneurysms can be adequately characterized using 1.5T and 3T MR imaging. Findings in a subgroup of patients can remain unclear due to difficulties in distinguishing aneurysms from vascular anatomic variants. We retrospectively analyzed clinical data from 30 patients with suspected incidental aneurysms on 3T MR imaging who underwent 7T MR imaging. In all 30 cases, the differentiation of an aneurysm versus a vascular variant could be achieved. In 20 cases (66%), the initial suspected diagnosis was revised. Our findings suggest that 7T MR imaging provides a clarification tool for the group of patients with suspected unruptured intracranial aneurysms and diagnostic ambiguity after standard 3T MR imaging.
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Affiliation(s)
- P Radojewski
- From the Institute of Diagnostic and Interventional Neuroradiology (P.R., J.S., R.W., P.M.), Bern University Hospital, Inselspital, University of Bern, Bern, Switzerland
| | - J Slotboom
- From the Institute of Diagnostic and Interventional Neuroradiology (P.R., J.S., R.W., P.M.), Bern University Hospital, Inselspital, University of Bern, Bern, Switzerland
| | - A Joseph
- Advanced Clinical Imaging Technology (A.J.), Siemens Healthcare AG, Bern, Switzerland.,Translational Imaging Center (A.J.), Sitem-Insel, Bern, Switzerland.,Departments of Radiology and Biomedical Research (A.J.), University of Bern, Bern, Switzerland
| | - R Wiest
- From the Institute of Diagnostic and Interventional Neuroradiology (P.R., J.S., R.W., P.M.), Bern University Hospital, Inselspital, University of Bern, Bern, Switzerland
| | - P Mordasini
- From the Institute of Diagnostic and Interventional Neuroradiology (P.R., J.S., R.W., P.M.), Bern University Hospital, Inselspital, University of Bern, Bern, Switzerland
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9
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Vachha B, Huang SY. MRI with ultrahigh field strength and high-performance gradients: challenges and opportunities for clinical neuroimaging at 7 T and beyond. Eur Radiol Exp 2021; 5:35. [PMID: 34435246 PMCID: PMC8387544 DOI: 10.1186/s41747-021-00216-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 03/30/2021] [Indexed: 12/12/2022] Open
Abstract
Research in ultrahigh magnetic field strength combined with ultrahigh and ultrafast gradient technology has provided enormous gains in sensitivity, resolution, and contrast for neuroimaging. This article provides an overview of the technical advantages and challenges of performing clinical neuroimaging studies at ultrahigh magnetic field strength combined with ultrahigh and ultrafast gradient technology. Emerging clinical applications of 7-T MRI and state-of-the-art gradient systems equipped with up to 300 mT/m gradient strength are reviewed, and the impact and benefits of such advances to anatomical, structural and functional MRI are discussed in a variety of neurological conditions. Finally, an outlook and future directions for ultrahigh field MRI combined with ultrahigh and ultrafast gradient technology in neuroimaging are examined.
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Affiliation(s)
- Behroze Vachha
- Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Ave, New York, NY, 10065, USA
| | - Susie Y Huang
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, 149 13th Street, Room 2301, Charlestown, MA, 02129, USA.
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10
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Carotid Artery Plaque Identification and Display System (MRI-CAPIDS) Using Opensource Tools. Diagnostics (Basel) 2020; 10:diagnostics10121111. [PMID: 33371362 PMCID: PMC7767364 DOI: 10.3390/diagnostics10121111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 12/07/2020] [Accepted: 12/15/2020] [Indexed: 11/21/2022] Open
Abstract
Magnetic resonance imaging (MRI) represents one modality in atherosclerosis risk assessment, by permitting the classification of carotid plaques into either high- or low-risk lesions. Although MRI is generally used for observing the impact of atherosclerosis on vessel lumens, it can also show both the size and composition of itself, as well as plaque information, thereby providing information beyond that of simple stenosis. Software systems are a valuable aid in carotid artery stenosis assessment wherein commercial software is readily available but is not accessible to all practitioners because of its often high cost. This study focuses on the development of a software system designed entirely for registration, marking, and 3D visualization of the wall and lumen, using freely available open-source tools and libraries. It was designed to be free from “feature bloat” and avoid “feature-creep.” The image loading and display module of the modified QDCM library was improved by a minimum of 10,000%. A Bezier function was used in order to smoothen the curve of the polygon (referring to the shape formed by the marked points) by interpolating additional points between the marked points. This smoother curve led to a smoother 3D view of the lumen and wall.
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11
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Leemans E, Cornelissen B, Sing MLC, Sprengers M, van den Berg R, Roos Y, Vandertop WP, Slump C, Marquering H, Majoie C. 7T versus 3T MR Angiography to Assess Unruptured Intracranial Aneurysms. J Neuroimaging 2020; 30:779-785. [PMID: 32857906 PMCID: PMC7754498 DOI: 10.1111/jon.12772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 07/24/2020] [Accepted: 08/03/2020] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND AND PURPOSE Aneurysm size and neck measurements are important for treatment decisions. The introduction of 7T magnetic resonance angiography (MRA) led to new possibilities assessing aneurysm morphology and flow due to the higher signal-to-noise ratio. However, it is unknown if the size measurements on 7T MRA are similar to those on the standard 3T MRA. This study aimed to compare aneurysm size measurements between 7T and 3T MRA. METHODS We included 18 patients with 22 aneurysms who underwent both 3T and 7T MRA. Three acquisition protocols were compared: 3T time of flight (TOF), 7T TOF, and 7T contrast-enhanced MRA. Each aneurysm on each protocol was measured by at least two experienced neuroradiologists. Subsequently, the differences were evaluated using scatterplots and the intraclass correlation coefficients (ICC) of agreement. RESULTS There was a good agreement among the neuroradiologists for the height and width measurements (mean ICC: .78-.93); the neck measurements showed a moderate agreement with a mean ICC of .57-.72. Between the MR acquisition protocols, there was a high agreement for all measurements with a mean ICC of .81-.96. Measurement differences between acquisition protocols (0-2.9 mm) were in the range of the differences between the neuroradiologists (0-3.6 mm). CONCLUSION Our study showed that 7T MRA, both nonenhanced and contrast-enhanced, has a high agreement in aneurysm size measurements compared to 3T. This suggests that 7T is useful for reliable aneurysm size assessment.
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Affiliation(s)
- Eva Leemans
- Department of Biomedical Engineering & Physics, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands.,Department of Radiology and Nuclear Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Bart Cornelissen
- Department of Biomedical Engineering & Physics, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands.,MIRA Institute for Biomedical Engineering and Technical Medicine, University of Twente, Enschede, the Netherlands
| | - M L C Sing
- Department of Biomedical Engineering & Physics, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Marieke Sprengers
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Rene van den Berg
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Yvo Roos
- Department of Neurology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - W Pieter Vandertop
- Neurosurgical Center Amsterdam, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Cornelius Slump
- MIRA Institute for Biomedical Engineering and Technical Medicine, University of Twente, Enschede, the Netherlands
| | - Henk Marquering
- Department of Biomedical Engineering & Physics, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands.,Department of Radiology and Nuclear Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Charles Majoie
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
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12
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Cerebral artery segmentation based on magnetization-prepared two rapid acquisition gradient echo multi-contrast images in 7 Tesla magnetic resonance imaging. Neuroimage 2020; 222:117259. [PMID: 32798680 DOI: 10.1016/j.neuroimage.2020.117259] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 07/12/2020] [Accepted: 08/03/2020] [Indexed: 11/20/2022] Open
Abstract
Cerebral artery segmentation plays an important role in the direct visualization of the human brain to obtain vascular system information. On ultra-high field magnetic resonance imaging, cerebral arteries appearing hyperintense on T1 weighted (T1w) images could be segmented from brain tissues such as gray and white matter. In this study, we propose an automated method to segment the cerebral arteries using multi-contrast images including T1w images of a magnetization-prepared two rapid acquisition gradient echo (MP2RAGE) sequence at 7 T. The proposed method, termed MP2rase-CA (MP2rage based RApid SEgmentation Cerebral Artery), employed a seed-based region-growing strategy and Frangi filtering as well as our brain tissue segmentation (MP2rase Brain Tissue). Time-of-flight (TOF) magnetic resonance angiography (MRA) images were obtained as a reference to evaluate the MP2rase-CA. We successfully performed vessel segmentations, from T1w MP2RAGE images, which mostly overlapped with the segmentations of large cerebral arteries from the TOF-MRA. We also investigated the effect of the large cerebral arteries on spatial transformation of anatomical images to standard coordinate space using vessel segmentation by MP2rase-CA. As a result, the T1w image without the cerebral arteries by MP2rase-CA showed better agreement with the standard atlas compared with the T1w image containing the arteries. In addition, voxel-based morphology showed significant differences between T1w images with and without cerebral arteries in brain areas nearby large arteries. Thus, because MP2rase-CA using MP2RAGE images can obtain brain tissue anatomical information as well as relatively large cerebral artery information without need for additional structure acquisition, it is useful and time saving for functional and structural studies.
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13
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Rutland JW, Delman BN, Gill CM, Zhu C, Shrivastava RK, Balchandani P. Emerging Use of Ultra-High-Field 7T MRI in the Study of Intracranial Vascularity: State of the Field and Future Directions. AJNR Am J Neuroradiol 2020; 41:2-9. [PMID: 31879330 DOI: 10.3174/ajnr.a6344] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 10/15/2019] [Indexed: 12/23/2022]
Abstract
Cerebrovascular disease is a major source of mortality that commonly requires neurosurgical intervention. MR imaging is the preferred technique for imaging cerebrovascular structures, as well as regions of pathology that include microbleeds and ischemia. Advanced MR imaging sequences such as time-of-flight, susceptibility-weighted imaging, and 3D T2-weighted sequences have demonstrated excellent depiction of arterial and venous structures with and without contrast administration. While the advantages of 3T compared with 1.5T have been described, the role of ultra-high-field (7T) MR imaging in neurovascular imaging remains poorly understood. In the present review, we examine emerging neurosurgical applications of 7T MR imaging in vascular imaging of diverse conditions and discuss current limitations and future directions for this technique.
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Affiliation(s)
- J W Rutland
- From the Translational and Molecular Imaging Institute (J.W.R., B.N.D., P.B.)
- Departments of Neurosurgery (J.W.R., C.M.G., R.K.S.)
| | - B N Delman
- From the Translational and Molecular Imaging Institute (J.W.R., B.N.D., P.B.)
- Diagnostic, Molecular, and Interventional Radiology (B.N.D.), Icahn School of Medicine at Mount Sinai, New York, New York
| | - C M Gill
- Departments of Neurosurgery (J.W.R., C.M.G., R.K.S.)
| | - C Zhu
- Department of Radiology and Biomedical Imaging (C.Z.), University of California San Francisco, San Francisco, California
| | | | - P Balchandani
- From the Translational and Molecular Imaging Institute (J.W.R., B.N.D., P.B.)
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14
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Millesi M, Knosp E, Mach G, Hainfellner JA, Ricken G, Trattnig S, Gruber A. Focal irregularities in 7-Tesla MRI of unruptured intracranial aneurysms as an indicator for areas of altered blood-flow parameters. Neurosurg Focus 2019; 47:E7. [PMID: 31786557 DOI: 10.3171/2019.9.focus19489] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 09/09/2019] [Indexed: 11/06/2022]
Abstract
OBJECTIVE In the last several decades, various factors have been studied for a better evaluation of the risk of rupture in incidentally discovered intracranial aneurysms (IAs). With advanced MRI, attempts were made to delineate the wall of IAs to identify weak areas prone to rupture. However, the field strength of the MRI investigations was insufficient for reasonable image resolution in many of these studies. Therefore, the aim of this study was to analyze findings of IAs in ultra-high field MRI at 7 Tesla (7 T). METHODS Patients with incidentally found IAs of at least 5 mm in diameter were included in this study and underwent MRI investigations at 7 T. At this field strength a hyperintense intravascular signal can be observed on nonenhanced images with a brighter "rim effect" along the vessel wall. Properties of this rim effect were evaluated and compared with computational fluid dynamics (CFD) analyses. RESULTS Overall, 23 aneurysms showed sufficient image quality for further evaluation. In 22 aneurysms focal irregularities were identified within this rim effect. Areas of such irregularities showed significantly higher values in wall shear stress and vorticity compared to areas with a clearly visible rim effect (p = 0.043 in both). CONCLUSIONS A hyperintense rim effect along the vessel wall was observed in most cases. Focal irregularities within this rim effect showed higher values of the mean wall shear stress and vorticity when compared by CFD analyses. Therefore, these findings indicate alterations in blood flow in IAs within these areas.
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Affiliation(s)
- Matthias Millesi
- 1Department of Neurosurgery.,3Cerebrovascular Research Group Vienna
| | | | | | | | | | - Siegfried Trattnig
- 5High Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna; and
| | - Andreas Gruber
- 1Department of Neurosurgery.,2Department of Neurosurgery, Johannes Kepler University Linz, Austria.,3Cerebrovascular Research Group Vienna
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15
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Grochowski C, Krukow P, Jonak K, Stępniewski A, Wawrzycki K, Maciejewski R. The assessment of lenticulostriate arteries originating from middle cerebral artery using ultra high-field magnetic resonance time-of-flight angiography. J Clin Neurosci 2019; 68:262-265. [PMID: 31331750 DOI: 10.1016/j.jocn.2019.07.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 05/31/2019] [Accepted: 07/05/2019] [Indexed: 11/30/2022]
Abstract
Time-of-flight angiography (ToF) was presented for the first time by Suryan and used by Hinshaw et al. This protocol allows to visualize blood flow within the vessels in vivo without the contrast administration, which is possible due to the large magnitude of magnetization, received from the moving spins and small magnitude of magnetization received from the stationary spins. Fourteen participants (male:female = 7:7) were analyzed, who have never been diagnosed with any central nervous system disease as well as any cardiovascular, metabolic disease and have never had any trauma. Although, the gold standard of cerebral vessel analysis is still DSA, ultra high-field 3D ToF-MRA shows clearer picture of all LSAs and the branches of LSAs in comparison to poor in contrast DSA imaging. Ultra high-field time-of-flight MRA is a valuable method in visualizing small perforating arteries, which can be used in the future as a diagnostic tool for clinical practice. The diversity of LSAs morphometry is vast and may alter during aging, thus the clinical anatomy of those vessels should be further investigated in vivo.
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Affiliation(s)
- Cezary Grochowski
- Department of Anatomy, Medical University of Lublin, Jaczewskiego 4, 20-090 Lublin, Poland; Department of Neurosurgery and Pediatric Neurosurgery, Medical University of Lublin, Jaczewskiego 8, 20-954 Lublin, Poland; Ecotech-Complex, Maria Curie-Skłodowska University, Lublin, Poland.
| | - Paweł Krukow
- Department of Clinical Neuropsychiatry, Medical University of Lublin, Lublin, Poland; Ecotech-Complex, Maria Curie-Skłodowska University, Lublin, Poland
| | - Kamil Jonak
- Department of Psychiatry, Psychotherapy and Early Intervention, Medical University of Lublin, Lublin, Poland; Institute of Technological Systems of Information, Lublin University of Technology, Poland; Ecotech-Complex, Maria Curie-Skłodowska University, Lublin, Poland
| | | | - Konrad Wawrzycki
- Electroradiology Department, Medical University of Lublin, Poland
| | - Ryszard Maciejewski
- Department of Anatomy, Medical University of Lublin, Jaczewskiego 4, 20-090 Lublin, Poland; Ecotech-Complex, Maria Curie-Skłodowska University, Lublin, Poland
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Samaniego EA, Roa JA, Hasan D. Vessel wall imaging in intracranial aneurysms. J Neurointerv Surg 2019; 11:1105-1112. [PMID: 31337731 DOI: 10.1136/neurintsurg-2019-014938] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 05/30/2019] [Accepted: 06/05/2019] [Indexed: 01/06/2023]
Abstract
High-resolution vessel wall imaging (HR-VWI) is becoming a useful tool in the characterization and identification of unstable unruptured brain aneurysms. However, it has not been validated for clinical use. The current evidence on HR-VWI techniques for characterization of brain aneurysms is described in this review. Specific imaging approaches such as aneurysm wall contrast enhancement, MRI-quantitative susceptibility mapping, and 7T MRI are described in detail.
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Affiliation(s)
- Edgar A Samaniego
- Neurology, Neurosurgery and Radiology, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - Jorge A Roa
- Neurology and Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
| | - David Hasan
- Neurosurgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA
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17
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Barisano G, Sepehrband F, Ma S, Jann K, Cabeen R, Wang DJ, Toga AW, Law M. Clinical 7 T MRI: Are we there yet? A review about magnetic resonance imaging at ultra-high field. Br J Radiol 2018; 92:20180492. [PMID: 30359093 DOI: 10.1259/bjr.20180492] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
In recent years, ultra-high field MRI (7 T and above) has received more interest for clinical imaging. Indeed, a number of studies have shown the benefits from the application of this powerful tool not only for research purposes, but also in realms of improved diagnostics and patient management. The increased signal-to-noise ratio and higher spatial resolution compared with conventional and high-field clinical scanners allow imaging of small anatomical detail and subtle pathological findings. Furthermore, greater spectral resolution achieved at ultra-high field allows the resolution of metabolites for MR spectroscopic imaging. All these advantages have a significant impact on many neurological diseases, including multiple sclerosis, cerebrovascular disease, brain tumors, epilepsy and neurodegenerative diseases, in part because the pathology can be subtle and lesions small in these diseases, therefore having higher signal and resolution will help lesion detection. In this review, we discuss the main clinical neurological applications and some technical challenges which remain with ultra-high field MRI.
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Affiliation(s)
- Giuseppe Barisano
- 1 Department of Radiology, Keck Medical Center of University of Southern California , Los Angeles, CA , USA.,2 Stevens Neuroimaging and Informatics Institute, University of Southern California , Los Angeles, CA , USA
| | - Farshid Sepehrband
- 2 Stevens Neuroimaging and Informatics Institute, University of Southern California , Los Angeles, CA , USA
| | - Samantha Ma
- 2 Stevens Neuroimaging and Informatics Institute, University of Southern California , Los Angeles, CA , USA
| | - Kay Jann
- 2 Stevens Neuroimaging and Informatics Institute, University of Southern California , Los Angeles, CA , USA
| | - Ryan Cabeen
- 2 Stevens Neuroimaging and Informatics Institute, University of Southern California , Los Angeles, CA , USA
| | - Danny J Wang
- 2 Stevens Neuroimaging and Informatics Institute, University of Southern California , Los Angeles, CA , USA
| | - Arthur W Toga
- 2 Stevens Neuroimaging and Informatics Institute, University of Southern California , Los Angeles, CA , USA
| | - Meng Law
- 1 Department of Radiology, Keck Medical Center of University of Southern California , Los Angeles, CA , USA.,2 Stevens Neuroimaging and Informatics Institute, University of Southern California , Los Angeles, CA , USA
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De Cocker LJ, Lindenholz A, Zwanenburg JJ, van der Kolk AG, Zwartbol M, Luijten PR, Hendrikse J. Clinical vascular imaging in the brain at 7T. Neuroimage 2018; 168:452-458. [PMID: 27867089 PMCID: PMC5862656 DOI: 10.1016/j.neuroimage.2016.11.044] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Revised: 09/30/2016] [Accepted: 11/16/2016] [Indexed: 01/23/2023] Open
Abstract
Stroke and related cerebrovascular diseases are a major cause of mortality and disability. Even at standard-field-strengths (1.5T), MRI is by far the most sensitive imaging technique to detect acute brain infarctions and to characterize incidental cerebrovascular lesions, such as white matter hyperintensities, lacunes and microbleeds. Arterial time-of-flight (TOF) MR angiography (MRA) can depict luminal narrowing or occlusion of the major brain feeding arteries, and this without the need for contrast administration. Compared to 1.5T MRA, the use of high-field strength (3T) and even more so ultra-high-field strengths (7T), enables the visualization of the lumen of much smaller intracranial vessels, while adding a contrast agent to TOF MRA at 7T may enable the visualization of even more distal arteries in addition to veins and venules. Moreover, with 3T and 7T, the arterial vessel walls beyond the circle of Willis become visible with high-resolution vessel wall imaging. In addition, with 7T MRI, the brain parenchyma can now be visualized on a submillimeter scale. As a result, high-resolution imaging studies of the brain and its blood supply at 7T have generated new concepts of different cerebrovascular diseases. In the current article, we will discuss emerging clinical applications and future directions of vascular imaging in the brain at 7T MRI.
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Affiliation(s)
- Laurens Jl De Cocker
- Department of Radiology, University Medical Center Utrecht, The Netherlands; Department of Radiology, Kliniek Sint-Jan, Brussels, Belgium.
| | - Arjen Lindenholz
- Department of Radiology, University Medical Center Utrecht, The Netherlands
| | - Jaco Jm Zwanenburg
- Department of Radiology, University Medical Center Utrecht, The Netherlands
| | | | - Maarten Zwartbol
- Department of Radiology, University Medical Center Utrecht, The Netherlands
| | - Peter R Luijten
- Department of Radiology, University Medical Center Utrecht, The Netherlands
| | - Jeroen Hendrikse
- Department of Radiology, University Medical Center Utrecht, The Netherlands
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How to choose the right MR sequence for your research question at 7 T and above? Neuroimage 2018; 168:119-140. [DOI: 10.1016/j.neuroimage.2017.04.044] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 04/18/2017] [Accepted: 04/19/2017] [Indexed: 12/29/2022] Open
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20
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Current Perspectives in Imaging Modalities for the Assessment of Unruptured Intracranial Aneurysms: A Comparative Analysis and Review. World Neurosurg 2018; 113:280-292. [PMID: 29360591 DOI: 10.1016/j.wneu.2018.01.054] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 01/05/2018] [Accepted: 01/11/2018] [Indexed: 12/29/2022]
Abstract
BACKGROUND Intracranial aneurysms (IAs) are pathologic dilatations of cerebral arteries. This systematic review summarizes and compares imaging techniques for assessing unruptured IAs (UIAs). This review also addresses their uses in different scopes of practice. Pathophysiologic mechanisms are reviewed to better understand the clinical usefulness of each imaging modality. METHODS A literature review was performed using PubMed with these search terms: "intracranial aneurysm," "cerebral aneurysm," "magnetic resonance angiography (MRA)," computed tomography angiography (CTA)," "catheter angiography," "digital subtraction angiography," "molecular imaging," "ferumoxytol," and "myeloperoxidase". Only studies in English were cited. RESULTS Since the development and improvement of noninvasive diagnostic imaging (computed tomography angiography and magnetic resonance angiography), many prospective studies and meta-analyses have compared these tests with gold standard digital subtraction angiography (DSA). Although computed tomography angiography and magnetic resonance angiography have lower detection rates for UIAs, they are vital in the treatment and follow-up of UIAs. The reduction in ionizing radiation and lack of endovascular instrumentation with these modalities provide benefits compared with DSA. Novel molecular imaging techniques to detect inflammation within the aneurysmal wall with the goal of stratifying risk based on level of inflammation are under investigation. CONCLUSIONS DSA remains the gold standard for preoperative planning and follow-up for patients with IA. Newer imaging modalities such as ferumoxytol-enhanced magnetic resonance imaging are emerging techniques that provide critical in vivo information about the inflammatory milieu within aneurysm walls. With further study, these techniques may provide aneurysm rupture risk and prediction models for individualized patient care.
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21
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Laader A, Beiderwellen K, Kraff O, Maderwald S, Wrede K, Ladd ME, Lauenstein TC, Forsting M, Quick HH, Nassenstein K, Umutlu L. 1.5 versus 3 versus 7 Tesla in abdominal MRI: A comparative study. PLoS One 2017; 12:e0187528. [PMID: 29125850 PMCID: PMC5695282 DOI: 10.1371/journal.pone.0187528] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 10/21/2017] [Indexed: 01/04/2023] Open
Abstract
Objectives The aim of this study was to investigate and compare the feasibility as well as potential impact of altered magnetic field properties on image quality and potential artifacts of 1.5 Tesla, 3 Tesla and 7 Tesla non-enhanced abdominal MRI. Materials and methods Magnetic Resonance (MR) imaging of the upper abdomen was performed in 10 healthy volunteers on a 1.5 Tesla, a 3 Tesla and a 7 Tesla MR system. The study protocol comprised a (1) T1-weighted fat-saturated spoiled gradient-echo sequence (2D FLASH), (2) T1-weighted fat-saturated volumetric interpolated breath hold examination sequence (3D VIBE), (3) T1-weighted 2D in and opposed phase sequence, (4) True fast imaging with steady-state precession sequence (TrueFISP) and (5) T2-weighted turbo spin-echo (TSE) sequence. For comparison reasons field of view and acquisition times were kept comparable for each correlating sequence at all three field strengths, while trying to achieve the highest possible spatial resolution. Qualitative and quantitative analyses were tested for significant differences. Results While 1.5 and 3 Tesla MRI revealed comparable results in all assessed features and sequences, 7 Tesla MRI yielded considerable differences in T1 and T2 weighted imaging. Benefits of 7 Tesla MRI encompassed an increased higher spatial resolution and a non-enhanced hyperintense vessel signal at 7 Tesla, potentially offering a more accurate diagnosis of abdominal parenchymatous and vasculature disease. 7 Tesla MRI was also shown to be more impaired by artifacts, including residual B1 inhomogeneities, susceptibility and chemical shift artifacts, resulting in reduced overall image quality and overall image impairment ratings. While 1.5 and 3 Tesla T2w imaging showed equivalently high image quality, 7 Tesla revealed strong impairments in its diagnostic value. Conclusions Our results demonstrate the feasibility and overall comparable imaging ability of T1-weighted 7 Tesla abdominal MRI towards 3 Tesla and 1.5 Tesla MRI, yielding a promising diagnostic potential for non-enhanced Magnetic Resonance Angiography (MRA). 1.5 Tesla and 3 Tesla offer comparably high-quality T2w imaging, showing superior diagnostic quality over 7 Tesla MRI.
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Affiliation(s)
- Anja Laader
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstr. 55, Essen, Germany
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Kokereiallee 7, Essen, Germany
- * E-mail:
| | - Karsten Beiderwellen
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstr. 55, Essen, Germany
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Kokereiallee 7, Essen, Germany
| | - Oliver Kraff
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Kokereiallee 7, Essen, Germany
| | - Stefan Maderwald
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Kokereiallee 7, Essen, Germany
| | - Karsten Wrede
- Department of Neurosurgery, University Hospital Essen, Hufelandstr. 55, Essen, Germany
| | - Mark E. Ladd
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Kokereiallee 7, Essen, Germany
- German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, Heidelberg, Germany
| | - Thomas C. Lauenstein
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstr. 55, Essen, Germany
- Institute of Radiology, Evangelisches Krankenhaus Düsseldorf, Kirchfeldstr. 40, Düsseldorf, Germany
| | - Michael Forsting
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstr. 55, Essen, Germany
| | - Harald H. Quick
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Kokereiallee 7, Essen, Germany
- High Field and Hybrid MR Imaging, University Hospital Essen, Hufelandstr. 55, Essen, Germany
| | - Kai Nassenstein
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstr. 55, Essen, Germany
| | - Lale Umutlu
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstr. 55, Essen, Germany
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Kokereiallee 7, Essen, Germany
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Grochowski C, Staśkiewicz G. Ultra high field TOF-MRA: A method to visualize small cerebral vessels. 7T TOF-MRA sequence parameters on different MRI scanners - Literature review. Neurol Neurochir Pol 2017; 51:411-418. [PMID: 28774679 DOI: 10.1016/j.pjnns.2017.06.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 05/02/2017] [Accepted: 06/30/2017] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Time-of-flight (TOF) angiography is a technique allowing to visualize the blood flow in vessels. 7T ToF-MRA is able to visualize the whole Circle of Willis including small perforating branches without any known side effects as opposed to usually used DSA and CTA with high exposition to the radiation and high doses of contrast as far as CTA is concerned. AIM The aim of this review is to describe ultra-high field ToF-MRA and present different protocol data depending on the scanner used in the study. MATERIALS AND METHODS PubMed, Embase, Ovid, Google Scholar databases were searched. Selection of studies for this systematic review included 7T magnetic resonance angiography studies. We searched for type of head coil used in various studies, flip angle, echo time, repetition time, field-of-view (FOV), number of slices per slab, matrix, voxel size and acquisition time. DISCUSSION Visualization for the small perforating vessels of the Circle of Willis, that are not fully visualized using low-field-strength MRA is improving with increasing magnetic field strength, which has been proved by several studies. CONCLUSION Ultra-high filed ToF-MRA has found to be a superior method in depicting cerebral microvasculature. 7T ToF-MRA seems to be a reliable method for visualization of arteries up to the second order cerebral arteries and has a potential to replace DSA.
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Affiliation(s)
- Cezary Grochowski
- Neurosurgery and Pediatric Neurosurgery Department in Lublin, Medical University of Lublin, Poland.
| | - Grzegorz Staśkiewicz
- Department of Anatomy in Lublin ul. Jaczewskiego 4 (Collegium Anatomicum), Lublin 20-090, Poland
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23
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Kraff O, Quick HH. 7T: Physics, safety, and potential clinical applications. J Magn Reson Imaging 2017; 46:1573-1589. [DOI: 10.1002/jmri.25723] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 03/17/2017] [Indexed: 12/19/2022] Open
Affiliation(s)
- Oliver Kraff
- Erwin L. Hahn Institute for MR Imaging; University of Duisburg-Essen; Essen Germany
| | - Harald H. Quick
- Erwin L. Hahn Institute for MR Imaging; University of Duisburg-Essen; Essen Germany
- High Field and Hybrid MR Imaging; University Hospital Essen; Essen Germany
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Noureddine Y, Kraff O, Ladd ME, Wrede KH, Chen B, Quick HH, Schaefers G, Bitz AK. In vitro and in silico assessment of RF-induced heating around intracranial aneurysm clips at 7 Tesla. Magn Reson Med 2017; 79:568-581. [DOI: 10.1002/mrm.26650] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 01/11/2017] [Accepted: 01/26/2017] [Indexed: 11/12/2022]
Affiliation(s)
- Yacine Noureddine
- Erwin L. Hahn Institute for Magnetic Resonance Imaging; University Duisburg-Essen; Essen Germany
- MR:comp GmbH, MR Safety Testing Laboratory; Gelsenkirchen Germany
| | - Oliver Kraff
- Erwin L. Hahn Institute for Magnetic Resonance Imaging; University Duisburg-Essen; Essen Germany
| | - Mark E. Ladd
- Erwin L. Hahn Institute for Magnetic Resonance Imaging; University Duisburg-Essen; Essen Germany
- Division of Medical Physics in Radiology (E020); German Cancer Research Center (DKFZ); Heidelberg Germany
| | - Karsten H. Wrede
- Erwin L. Hahn Institute for Magnetic Resonance Imaging; University Duisburg-Essen; Essen Germany
- Department of Neurosurgery; University Hospital Essen; Essen Germany
| | - Bixia Chen
- Erwin L. Hahn Institute for Magnetic Resonance Imaging; University Duisburg-Essen; Essen Germany
- Department of Neurosurgery; University Hospital Essen; Essen Germany
| | - Harald H. Quick
- Erwin L. Hahn Institute for Magnetic Resonance Imaging; University Duisburg-Essen; Essen Germany
- High Field and Hybrid MR Imaging; University Hospital Essen; Essen Germany
| | - Gregor Schaefers
- MR:comp GmbH, MR Safety Testing Laboratory; Gelsenkirchen Germany
- MRI-STaR-Magnetic Resonance Institute for Safety, Technology and Research GmbH; Gelsenkirchen Germany
| | - Andreas K. Bitz
- Erwin L. Hahn Institute for Magnetic Resonance Imaging; University Duisburg-Essen; Essen Germany
- Division of Medical Physics in Radiology (E020); German Cancer Research Center (DKFZ); Heidelberg Germany
- Faculty of Electrical Engineering and Information Technology; FH Aachen-University of Applied Sciences; Aachen NRW Germany
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Abstract
Magnetic resonance imaging (MRI) plays a key role in the investigation of cerebrovascular diseases. Compared with computed tomography (CT) and digital subtraction angiography (DSA), its advantages in diagnosing cerebrovascular pathology include its superior tissue contrast, its ability to visualize blood vessels without the use of a contrast agent, and its use of magnetic fields and radiofrequency pulses instead of ionizing radiation. In recent years, ultrahigh field MRI at 7 tesla (7 T) has shown promise in the diagnosis of many cerebrovascular diseases. The increased signal-to-noise ratio (SNR; 2.3x and 4.7x increase compared with 3 and 1.5 T, respectively) and contrast-to-noise ratio (CNR) at this higher field strength can be exploited to obtain a higher spatial resolution and higher lesion conspicuousness, enabling assessment of smaller brain structures and lesions. Cerebrovascular diseases can be assessed at different tissue levels; for instance, changes of the arteries feeding the brain can be visualized to determine the cause of ischemic stroke, regional changes in brain perfusion can be mapped to predict outcome after revascularization, and tissue damage, including old and recent ischemic infarcts, can be evaluated as a marker of ischemic burden. For the purpose of this review, we will discriminate 3 levels of assessment of cerebrovascular diseases using MRI: Pipes, Perfusion, and Parenchyma (3 Ps). The term Pipes refers to the brain-feeding arteries from the heart and aortic arch, upwards to the carotid arteries, vertebral arteries, circle of Willis, and smaller intracranial arterial branches. Perfusion is the amount of blood arriving at the brain tissue level, and includes the vascular reserve and perfusion territories. Parenchyma refers to the acute and chronic burden of brain tissue damage, which includes larger infarcts, smaller microinfarcts, and small vessel disease manifestations such as white matter lesions, lacunar infarcts, and microbleeds. In this review, we will describe the key developments in the last decade of 7-T MRI of cerebrovascular diseases, subdivided for these 3 levels of assessment.
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Goll C, Thormann M, Hofmüller W, Friebe B, Behrens-Baumann W, Bley TA, Hoffmann MB, Speck O. Feasibility study: 7 T MRI in giant cell arteritis. Graefes Arch Clin Exp Ophthalmol 2016; 254:1111-6. [DOI: 10.1007/s00417-016-3337-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 03/20/2016] [Accepted: 03/28/2016] [Indexed: 11/24/2022] Open
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Dengler NF, Madai VI, Wuerfel J, von Samson-Himmelstjerna FC, Dusek P, Niendorf T, Sobesky J, Vajkoczy P. Moyamoya Vessel Pathology Imaged by Ultra-High-Field Magnetic Resonance Imaging at 7.0 T. J Stroke Cerebrovasc Dis 2016; 25:1544-51. [PMID: 27053027 DOI: 10.1016/j.jstrokecerebrovasdis.2016.01.041] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 01/20/2016] [Accepted: 01/29/2016] [Indexed: 10/22/2022] Open
Abstract
BACKGROUND Prompt diagnosis of vessel pathology and appropriate treatment of moyamoya vasculopathy (MMV) are essential to improve long-term prognosis. The aims of our study were to explore the diagnostic value of ultra-high-field (UHF) magnetic resonance imaging at 7.0 T in MMV patients and to compare the applicability of two different 7.0 T vessel imaging modalities to 3.0 T magnetic resonance angiography (MRA) and digital subtraction angiography (DSA). METHODS In a World Health Organization-registered and prospective imaging trial, patients were investigated at 7.0 T magnetization-prepared rapid-acquisition gradient echo (MPRAGE)-MRA and time-of-flight (TOF)-MRA, 3.0 T TOF-MRA, and by DSA. RESULTS Six patients were included in our study and evaluated for MMV. 3.0 T TOF-MRA and 7.0 T MPRAGE-MRA were able to depict the complete major vascular tree and confirmed MMV-specific steno-occlusions of major intracranial arteries, as previously identified by DSA. 7.0 T TOF-MRA was limited to visualization of the circle of Willis as well as the internal carotid artery only. Donor vessels for bypass surgery (i.e., branches of superficial temporal artery) could be sufficiently visualized with all magnetic resonance modalities. CONCLUSIONS Our results indicate that a specific 7.0 T vascular imaging protocol yields diagnostic information about vessel pathology in MMV that approximates conventional DSA. 7.0 T MPRAGE was superior to 7.0 T TOF-MRA due to shorter scanning times and better brain coverage. To date, however, limited availability of 7.0 T technology in medical facilities as well as technical and procedural constraints excludes a fair amount of patients from the clinical 7.0 T imaging process.
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Affiliation(s)
- Nora F Dengler
- Department of Neurosurgery, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Vince I Madai
- Department of Neurology, Charité Universitätsmedizin Berlin, Berlin, Germany; Center for Stroke Research Berlin (CSB), Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Jens Wuerfel
- Center for Stroke Research Berlin (CSB), Charité Universitätsmedizin Berlin, Berlin, Germany; Neurocure Clinical Research Centre, Charité Universitätsmedizin Berlin, Berlin, Germany; Institute of Neuroradiology, University Göttingen, Göttingen, Germany; Berlin Ultra-High Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany; Medical Image Analysis Center (MIAC AG), Basel, Switzerland
| | | | - Petr Dusek
- Institute of Neuroradiology, University Göttingen, Göttingen, Germany; Department of Neurology and Center of Clinical Neuroscience, Charles University in Prague, First Faculty of Medicine and General University Hospital in Prague, Praha, Czech Republic
| | - Thoralf Niendorf
- Berlin Ultra-High Field Facility (B.U.F.F.), Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Jan Sobesky
- Department of Neurology, Charité Universitätsmedizin Berlin, Berlin, Germany; Center for Stroke Research Berlin (CSB), Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Peter Vajkoczy
- Department of Neurosurgery, Charité Universitätsmedizin Berlin, Berlin, Germany.
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Chen B, Schoemberg T, Kraff O, Dammann P, Bitz AK, Schlamann M, Quick HH, Ladd ME, Sure U, Wrede KH. Cranial fixation plates in cerebral magnetic resonance imaging: a 3 and 7 Tesla in vivo image quality study. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2016; 29:389-98. [DOI: 10.1007/s10334-016-0548-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 03/02/2016] [Accepted: 03/10/2016] [Indexed: 01/26/2023]
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Wrede KH, Matsushige T, Goericke SL, Chen B, Umutlu L, Quick HH, Ladd ME, Johst S, Forsting M, Sure U, Schlamann M. Non-enhanced magnetic resonance imaging of unruptured intracranial aneurysms at 7 Tesla: Comparison with digital subtraction angiography. Eur Radiol 2016; 27:354-364. [DOI: 10.1007/s00330-016-4323-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 03/02/2016] [Accepted: 03/05/2016] [Indexed: 11/25/2022]
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Ultrahigh-field MPRAGE Magnetic Resonance Angiography at 7.0T in patients with cerebrovascular disease. Eur J Radiol 2015; 84:2613-7. [DOI: 10.1016/j.ejrad.2015.09.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Revised: 07/20/2015] [Accepted: 09/27/2015] [Indexed: 11/23/2022]
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Experience with magnetic resonance imaging of human subjects with passive implants and tattoos at 7 T: a retrospective study. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2015; 28:577-90. [DOI: 10.1007/s10334-015-0499-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Revised: 07/25/2015] [Accepted: 08/19/2015] [Indexed: 10/23/2022]
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Aracki-Trenkić A, Stojanov D, Ristić S, Radovanović Z, Ignjatović J, Lazović L, Petrović S, Trenkić M, Trenkic-Božinović M. DIAGNOSTIC ACCURACY OF MAGNETIC RESONANCE ANGIOGRAPHY FOR UNRUPTURED CEREBRAL ANEURYSMS IN CORRELATION WITH DIGITAL SUBTRACTION ANGIOGRAPHY. ACTA MEDICA MEDIANAE 2015. [DOI: 10.5633/amm.2015.0302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Gizewski ER, Mönninghoff C, Forsting M. Perspectives of Ultra-High-Field MRI in Neuroradiology. Clin Neuroradiol 2015; 25 Suppl 2:267-73. [PMID: 26184503 DOI: 10.1007/s00062-015-0437-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Accepted: 07/06/2015] [Indexed: 01/22/2023]
Abstract
PURPOSE Magnetic resonance imaging (MRI) is one of the most important methods for the diagnosis and therapy monitoring of various diseases. Today, magnets up to 3 T are standard. This review will give an overview of the clinical perspectives of ultra-high field MRI, meaning mainly 7 T. METHODS Literature review with focus on clinical applications of 7 T imaging in neuroscience combined with examples of own studies and perspectives. RESULTS This high-resolution technique offers the potential to improve certain tissue contrasts and signal in functional (fMRI) and metabolic (MRS) imaging. This overview demonstrates already existing potentials and advantages of the ultra-high magnetic field for central nervous system (CNS) diseases. CONCLUSIONS Although there are still some technical challenges for brain and spine imaging at 7 T, the method has clear benefit in selected structural, functional, and metabolic imaging.
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Affiliation(s)
- E R Gizewski
- Dept. of Neuroradiology, Medical University Innsbruck, Innsbruck, Austria. .,Universitätsklinik für Neuroradiologie, Medizinische Universität Innsbruck, Anichstr. 35, 6020, Innsbruck, Austria.
| | - C Mönninghoff
- Dept. of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany.,Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany
| | - M Forsting
- Dept. of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany.,Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany
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Wrede KH, Johst S, Dammann P, Özkan N, Mönninghoff C, Kraemer M, Maderwald S, Ladd ME, Sure U, Umutlu L, Schlamann M. Improved cerebral time-of-flight magnetic resonance angiography at 7 Tesla--feasibility study and preliminary results using optimized venous saturation pulses. PLoS One 2014; 9:e106697. [PMID: 25232868 PMCID: PMC4169393 DOI: 10.1371/journal.pone.0106697] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 08/07/2014] [Indexed: 11/24/2022] Open
Abstract
Purpose Conventional saturation pulses cannot be used for 7 Tesla ultra-high-resolution time-of-flight magnetic resonance angiography (TOF MRA) due to specific absorption rate (SAR) limitations. We overcome these limitations by utilizing low flip angle, variable rate selective excitation (VERSE) algorithm saturation pulses. Material and Methods Twenty-five neurosurgical patients (male n = 8, female n = 17; average age 49.64 years; range 26–70 years) with different intracranial vascular pathologies were enrolled in this trial. All patients were examined with a 7 Tesla (Magnetom 7 T, Siemens) whole body scanner system utilizing a dedicated 32-channel head coil. For venous saturation pulses a 35° flip angle was applied. Two neuroradiologists evaluated the delineation of arterial vessels in the Circle of Willis, delineation of vascular pathologies, presence of artifacts, vessel-tissue contrast and overall image quality of TOF MRA scans in consensus on a five-point scale. Normalized signal intensities in the confluence of venous sinuses, M1 segment of left middle cerebral artery and adjacent gray matter were measured and vessel-tissue contrasts were calculated. Results Ratings for the majority of patients ranged between good and excellent for most of the evaluated features. Venous saturation was sufficient for all cases with minor artifacts in arteriovenous malformations and arteriovenous fistulas. Quantitative signal intensity measurements showed high vessel-tissue contrast for confluence of venous sinuses, M1 segment of left middle cerebral artery and adjacent gray matter. Conclusion The use of novel low flip angle VERSE algorithm pulses for saturation of venous vessels can overcome SAR limitations in 7 Tesla ultra-high-resolution TOF MRA. Our protocol is suitable for clinical application with excellent image quality for delineation of various intracranial vascular pathologies.
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Affiliation(s)
- Karsten H. Wrede
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany
- Department of Neurosurgery, University Hospital Essen, Essen, Germany
- * E-mail:
| | - Sören Johst
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany
| | - Philipp Dammann
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany
- Department of Neurosurgery, University Hospital Essen, Essen, Germany
| | - Neriman Özkan
- Department of Neurosurgery, University Hospital Essen, Essen, Germany
| | - Christoph Mönninghoff
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany
| | - Markus Kraemer
- Department of Neurology, Alfried Krupp von Bohlen und Halbach Hospital, Essen, Germany
| | - Stefan Maderwald
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany
| | - Mark E. Ladd
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany
- Division of Medical Physics in Radiology (E020), German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Ulrich Sure
- Department of Neurosurgery, University Hospital Essen, Essen, Germany
| | - Lale Umutlu
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany
| | - Marc Schlamann
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany
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Štepán-Buksakowska IL, Accurso JM, Diehn FE, Huston J, Kaufmann TJ, Luetmer PH, Wood CP, Yang X, Blezek DJ, Carter R, Hagen C, Hořínek D, Hejčl A, Roček M, Erickson BJ. Computer-aided diagnosis improves detection of small intracranial aneurysms on MRA in a clinical setting. AJNR Am J Neuroradiol 2014; 35:1897-902. [PMID: 24924543 DOI: 10.3174/ajnr.a3996] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND AND PURPOSE MRA is widely accepted as a noninvasive diagnostic tool for the detection of intracranial aneurysms, but detection is still a challenging task with rather low detection rates. Our aim was to examine the performance of a computer-aided diagnosis algorithm for detecting intracranial aneurysms on MRA in a clinical setting. MATERIALS AND METHODS Aneurysm detectability was evaluated retrospectively in 48 subjects with and without computer-aided diagnosis by 6 readers using a clinical 3D viewing system. Aneurysms ranged from 1.1 to 6.0 mm (mean = 3.12 mm, median = 2.50 mm). We conducted a multireader, multicase, double-crossover design, free-response, observer-performance study on sets of images from different MRA scanners by using DSA as the reference standard. Jackknife alternative free-response operating characteristic curve analysis with the figure of merit was used. RESULTS For all readers combined, the mean figure of merit improved from 0.655 to 0.759, indicating a change in the figure of merit attributable to computer-aided diagnosis of 0.10 (95% CI, 0.03-0.18), which was statistically significant (F(1,47) = 7.00, P = .011). Five of the 6 radiologists had improved performance with computer-aided diagnosis, primarily due to increased sensitivity. CONCLUSIONS In conditions similar to clinical practice, using computer-aided diagnosis significantly improved radiologists' detection of intracranial DSA-confirmed aneurysms of ≤6 mm.
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Affiliation(s)
- I L Štepán-Buksakowska
- From the Department of Radiology (I.L.Š.-B., F.E.D., J.H., T.J.K., P.H.L., C.P.W., B.J.E.) International Clinical Research Center (I.L.Š.-B., D.H., A.H.), St. Anne's University Hospital Brno, Brno, Czech Republic Department of Radiology (I.L.Š.-B., M.R.), Second Faculty of Medicine, Charles University and University Hospital Motol, Prague, Czech Republic
| | - J M Accurso
- Department of Radiology (J.M.A.), Mayo Clinic, Jacksonville, Florida
| | - F E Diehn
- From the Department of Radiology (I.L.Š.-B., F.E.D., J.H., T.J.K., P.H.L., C.P.W., B.J.E.)
| | - J Huston
- From the Department of Radiology (I.L.Š.-B., F.E.D., J.H., T.J.K., P.H.L., C.P.W., B.J.E.)
| | - T J Kaufmann
- From the Department of Radiology (I.L.Š.-B., F.E.D., J.H., T.J.K., P.H.L., C.P.W., B.J.E.)
| | - P H Luetmer
- From the Department of Radiology (I.L.Š.-B., F.E.D., J.H., T.J.K., P.H.L., C.P.W., B.J.E.)
| | - C P Wood
- From the Department of Radiology (I.L.Š.-B., F.E.D., J.H., T.J.K., P.H.L., C.P.W., B.J.E.)
| | - X Yang
- Department of Information Services (X.Y., D.J.B.), Mayo Clinic, Rochester, Minnesota
| | - D J Blezek
- Department of Information Services (X.Y., D.J.B.), Mayo Clinic, Rochester, Minnesota
| | - R Carter
- Division of Biomedical Statistics and Informatics (R.C., C.H.)
| | - C Hagen
- Division of Biomedical Statistics and Informatics (R.C., C.H.)
| | - D Hořínek
- International Clinical Research Center (I.L.Š.-B., D.H., A.H.), St. Anne's University Hospital Brno, Brno, Czech Republic Department of Neurosurgery (D.H., A.H.), Masaryk Hospital, Ústí nad Labem, Czech Republic Department of Neurosurgery (D.H.), Central Military Hospital, Prague, Czech Republic
| | - A Hejčl
- International Clinical Research Center (I.L.Š.-B., D.H., A.H.), St. Anne's University Hospital Brno, Brno, Czech Republic Department of Neurosurgery (D.H., A.H.), Masaryk Hospital, Ústí nad Labem, Czech Republic
| | - M Roček
- Department of Radiology (I.L.Š.-B., M.R.), Second Faculty of Medicine, Charles University and University Hospital Motol, Prague, Czech Republic
| | - B J Erickson
- From the Department of Radiology (I.L.Š.-B., F.E.D., J.H., T.J.K., P.H.L., C.P.W., B.J.E.)
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Fischer A, Kraff O, Maderwald S, Beiderwellen K, Ladd ME, Forsting M, Lauenstein TC, Umutlu L. Non-enhanced T1-weighted liver vessel imaging at 7 Tesla. PLoS One 2014; 9:e97465. [PMID: 24887206 PMCID: PMC4041637 DOI: 10.1371/journal.pone.0097465] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Accepted: 04/21/2014] [Indexed: 11/18/2022] Open
Abstract
Objectives Aim of the study was to assess the feasibility and to compare three non-enhanced T1-weighted (w) sequences for liver vessel imaging at 7 Tesla (T). Material and Methods 12 healthy volunteers were examined on a 7 T whole-body MR-system. The following non-enhanced sequences were acquired: T1w 2D FLASH, T1w 3D FLASH and Time of flight (TOF)-MRA. Qualitative image analysis was performed by two radiologists including over all image quality as well as vessel delineation of the liver arteries, liver veins and portal vein and the presence of artifacts using a five-point scale (5 = excellent vessel delineation to 1 = non-diagnostic). Contrast ratios (CR), SNR und CNR of the above named vessels in correlation to adjacent liver tissue were calculated for quantitative assessment. For statistical analysis, a Wilcoxon Rank Test was applied. Results All three sequences provided a homogenous hyperintense delineation of the assessed liver vessels. Qualitative image analysis demonstrated the superiority of TOF-MRA, providing best overall image quality (TOF 4.17, 2D FLASH 3.42, 3D FLASH 3.46; p<0.01) as well as highest image quality values for all analyzed liver vessel segments. TOF-MRA was least impaired by B1 inhomogeneity (4.13) and susceptibility artifacts (4.63) out of all three sequences (p<0.01). Quantitative image analysis confirmed the superiority of TOF MRA showing significant higher CR values for all liver vessels (e.g. right hepatic artery TOF 0.47, 2D FLASH 0.09, 3D FLASH 0.11 with p = 0.02 and 0.01, respectively). Providing the lowest standard deviation in noise, TOF showed highest values for SNR and CNR. Conclusions Non-enhanced T1w imaging in general and TOF MRA in particular, appear to be promising techniques for high quality non-enhanced liver vessel assessment at 7 T.
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Affiliation(s)
- Anja Fischer
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany
- * E-mail:
| | - Oliver Kraff
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany
| | - Stefan Maderwald
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany
| | - Karsten Beiderwellen
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany
| | - Mark E. Ladd
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany
- German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Michael Forsting
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany
| | - Thomas C. Lauenstein
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany
| | - Lale Umutlu
- Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany
- Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany
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Noninvasive detection of aneurysms via 7 T MRI. Nat Rev Neurol 2014. [DOI: 10.1038/nrneurol.2014.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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