1
|
Perera Molligoda Arachchige AS, Meuli S, Centini FR, Stomeo N, Catapano F, Politi LS. Evaluating the role of 7-Tesla magnetic resonance imaging in neurosurgery: Trends in literature since clinical approval. World J Radiol 2024; 16:274-293. [PMID: 39086607 PMCID: PMC11287432 DOI: 10.4329/wjr.v16.i7.274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2024] [Revised: 05/08/2024] [Accepted: 06/17/2024] [Indexed: 07/24/2024] Open
Abstract
BACKGROUND After approval for clinical use in 2017, early investigations of ultra-high-field abdominal magnetic resonance imaging (MRI) have demonstrated its feasibility as well as diagnostic capabilities in neuroimaging. However, there are no to few systematic reviews covering the entirety of its neurosurgical applications as well as the trends in the literature with regard to the aforementioned application. AIM To assess the impact of 7-Tesla MRI (7T MRI) on neurosurgery, focusing on its applications in diagnosis, treatment planning, and postoperative assessment, and to systematically analyze and identify patterns and trends in the existing literature related to the utilization of 7T MRI in neurosurgical contexts. METHODS A systematic search of PubMed was conducted for studies published between January 1, 2017, and December 31, 2023, using MeSH terms related to 7T MRI and neurosurgery. The inclusion criteria were: Studies involving patients of all ages, meta-analyses, systematic reviews, and original research. The exclusion criteria were: Pre-prints, studies with insufficient data (e.g., case reports and letters), non-English publications, and studies involving animal subjects. Data synthesis involved standardized extraction forms, and a narrative synthesis was performed. RESULTS We identified 219 records from PubMed within our defined period, with no duplicates or exclusions before screening. After screening, 125 articles were excluded for not meeting inclusion criteria, leaving 94 reports. Of these, 2 were irrelevant to neurosurgery and 7 were animal studies, resulting in 85 studies included in our systematic review. Data were categorized by neurosurgical procedures and diseases treated using 7T MRI. We also analyzed publications by country and the number of 7T MRI facilities per country was also presented. Experimental studies were classified into comparison and non-comparison studies based on whether 7T MRI was compared to lower field strengths. CONCLUSION 7T MRI holds great potential in improving the characterization and understanding of various neurological and psychiatric conditions that may be neurosurgically treated. These include epilepsy, pituitary adenoma, Parkinson's disease, cerebrovascular diseases, trigeminal neuralgia, traumatic head injury, multiple sclerosis, glioma, and psychiatric disorders. Superiority of 7T MRI over lower field strengths was demonstrated in terms of image quality, lesion detection, and tissue characterization. Findings suggest the need for accelerated global distribution of 7T magnetic resonance systems and increased training for radiologists to ensure safe and effective integration into routine clinical practice.
Collapse
Affiliation(s)
| | - Sarah Meuli
- Faculty of Medicine, Humanitas University, Pieve Emanuele, Milan 20072, Italy
| | | | - Niccolò Stomeo
- Department of Anaesthesiology and Intensive Care, IRCCS Humanitas Research Hospital, Via Manzoni 56, Rozzano, Milan 20089, Italy
- Department of Biomedical Sciences, Humanitas University, via Rita Levi Montalcini 4, 20090 Pieve Emanuele - Milan, Italy
| | - Federica Catapano
- Department of Biomedical Sciences, Humanitas University, via Rita Levi Montalcini 4, 20090 Pieve Emanuele - Milan, Italy
- IRCCS Humanitas Research Hospital, Via Manzoni 56, 20089 Rozzano - Milan, Italy
| | - Letterio S Politi
- Department of Biomedical Sciences, Humanitas University, via Rita Levi Montalcini 4, 20090 Pieve Emanuele - Milan, Italy
- Department of Neuroradiology, IRCCS Humanitas Research Hospital, Via Manzoni 56, Rozzano, Milan 20089, Italy
| |
Collapse
|
2
|
Veeturi SS, Hall S, Fujimura S, Mossa-Basha M, Sagues E, Samaniego EA, Tutino VM. Imaging of Intracranial Aneurysms: A Review of Standard and Advanced Imaging Techniques. Transl Stroke Res 2024:10.1007/s12975-024-01261-w. [PMID: 38856829 DOI: 10.1007/s12975-024-01261-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 04/16/2024] [Accepted: 05/13/2024] [Indexed: 06/11/2024]
Abstract
The treatment of intracranial aneurysms is dictated by its risk of rupture in the future. Several clinical and radiological risk factors for aneurysm rupture have been described and incorporated into prediction models. Despite the recent technological advancements in aneurysm imaging, linear length and visible irregularity with a bleb are the only radiological measure used in clinical prediction models. The purpose of this article is to summarize both the standard imaging techniques, including their limitations, and the advanced techniques being used experimentally to image aneurysms. It is expected that as our understanding of advanced techniques improves, and their ability to predict clinical events is demonstrated, they become an increasingly routine part of aneurysm assessment. It is important that neurovascular specialists understand the spectrum of imaging techniques available.
Collapse
Affiliation(s)
- Sricharan S Veeturi
- Canon Stroke and Vascular Research Center, Clinical and Translational Research Center, University at Buffalo, 875 Ellicott Street, Buffalo, NY, 14214, USA
- Department of Neurosurgery, University at Buffalo, Buffalo, NY, USA
| | - Samuel Hall
- Department of Neurosurgery, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Soichiro Fujimura
- Department of Mechanical Engineering, Tokyo University of Science, Tokyo, Japan
- Division of Innovation for Medical Information Technology, The Jikei University School of Medicine, Tokyo, Japan
| | | | - Elena Sagues
- Department of Neurology, University of Iowa, Iowa City, IA, USA
| | | | - Vincent M Tutino
- Canon Stroke and Vascular Research Center, Clinical and Translational Research Center, University at Buffalo, 875 Ellicott Street, Buffalo, NY, 14214, USA.
- Department of Pathology and Anatomical Sciences, University at Buffalo, Buffalo, NY, USA.
| |
Collapse
|
3
|
Cosottini M, Calzoni T, Lazzarotti GA, Grigolini A, Bosco P, Cecchi P, Tosetti M, Biagi L, Donatelli G. Time-of-flight MRA of intracranial vessels at 7 T. Eur Radiol Exp 2024; 8:68. [PMID: 38844683 PMCID: PMC11156832 DOI: 10.1186/s41747-024-00463-z] [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: 12/29/2023] [Accepted: 04/03/2024] [Indexed: 06/09/2024] Open
Abstract
BACKGROUND Three-dimensional time-of-flight magnetic resonance angiography (TOF-MRA) is a largely adopted non-invasive technique for assessing cerebrovascular diseases. We aimed to optimize the 7-T TOF-MRA acquisition protocol, confirm that it outperforms conventional 3-T TOF-MRA, and compare 7-T TOF-MRA with digital subtraction angiography (DSA) in patients with different vascular pathologies. METHODS Seven-tesla TOF-MRA sequences with different spatial resolutions acquired in four healthy subjects were compared with 3-T TOF-MRA for signal-to-noise and contrast-to-noise ratios as well as using a qualitative scale for vessel visibility and the quantitative Canny algorithm. Four patients with cerebrovascular disease (primary arteritis of the central nervous system, saccular aneurism, arteriovenous malformation, and dural arteriovenous fistula) underwent optimized 7-T TOF-MRA and DSA as reference. Images were compared visually and using the complex-wavelet structural similarity index. RESULTS Contrast-to-noise ratio was higher at 7 T (4.5 ± 0.8 (mean ± standard deviation)) than at 3 T (2.7 ± 0.9). The mean quality score for all intracranial vessels was higher at 7 T (2.89) than at 3 T (2.28). Angiogram quality demonstrated a better vessel border detection at 7 T than at 3 T (44,166 versus 28,720 pixels). Of 32 parameters used for diagnosing cerebrovascular diseases on DSA, 27 (84%) were detected on 7-T TOF-MRA; the similarity index ranged from 0.52 (dural arteriovenous fistula) to 0.90 (saccular aneurysm). CONCLUSIONS Seven-tesla TOF-MRA outperformed conventional 3-T TOF-MRA in evaluating intracranial vessels and exhibited an excellent image quality when compared to DSA. Seven-tesla TOF-MRA might improve the non-invasive diagnostic approach to several cerebrovascular diseases. RELEVANCE STATEMENT An optimized TOF-MRA sequence at 7 T outperforms 3-T TOF-MRA, opening perspectives to its clinical use for noninvasive diagnosis of paradigmatic pathologies of intracranial vessels. KEY POINTS • An optimized 7-T TOF-MRA protocol was selected for comparison with clinical 3-T TOF-MRA for assessing intracranial vessels. • Seven-tesla TOF-MRA outperformed 3-T TOF-MRA in both quantitative and qualitative evaluation. • Seven-tesla TOF-MRA is comparable to DSA for the diagnosis and characterization of intracranial vascular pathologies.
Collapse
Affiliation(s)
- Mirco Cosottini
- Department of Translational Research on New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy.
- Neuroradiology Unit, Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy.
| | - Tommaso Calzoni
- Department of Translational Research on New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | | | | | - Paolo Bosco
- Laboratory of Medical Physics and Magnetic Resonance, IRCCS Stella Maris, Pisa, Italy
| | - Paolo Cecchi
- Department of Translational Research on New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
- Imago7 Research Foundation, Pisa, Italy
| | - Michela Tosetti
- Laboratory of Medical Physics and Magnetic Resonance, IRCCS Stella Maris, Pisa, Italy
| | - Laura Biagi
- Laboratory of Medical Physics and Magnetic Resonance, IRCCS Stella Maris, Pisa, Italy
| | - Graziella Donatelli
- Department of Translational Research on New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
- Imago7 Research Foundation, Pisa, Italy
| |
Collapse
|
4
|
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.
| |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
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.
Collapse
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
| |
Collapse
|
7
|
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.
Collapse
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
| | | | | | | | | |
Collapse
|
8
|
Abstract
OBJECTIVES Intracranial aneurysm (IA) is the main cause of subarachnoid hemorrhages. Time-of-flight (TOF) magnetic resonance angiography (MRA) at 1.5 T or 3 T magnetic resonance imaging (MRI) is a well-established method for the diagnosis of IA. The aim of this prospective study was to evaluate the performance of a modern 0.55 T MRI in the diagnosis of IAs in comparison to digital subtraction angiography (DSA) as a standard of reference. MATERIALS AND METHODS Seventeen patients with suspicion of single or multiple IAs underwent TOF MRA at 0.55 T MRI 1 day before DSA. Two neuroradiologists independently measured the aneurysm neck, width, and height on 0.55 T, 1.5 T, and 3 T 3D-TOF MRA source images and 2D/3D rotational angiography. The main analysis assessed the intermodality agreement between 0.55 T TOF MRA and DSA using Bland-Altman plots, a Wilcoxon test, and the intraclass correlation coefficient (ICC). In a secondary analysis, aneurysm dimensions were compared between 0.55 T TOF MRA and 1.5/3 T TOF MRA. Interreader agreement was evaluated by ICC. A third neuroradiologist blinded to patient history screened 0.55 T TOF MRA data sets of the aforementioned 17 patients and 15 additional healthy patients for the presence and location of aneurysms. RESULTS A total of 19 aneurysms in 16 patients were identified in both 0.55 T MRA and DSA. Measurements of the 2 nonblinded readers showed no significant differences between 0.55 T TOF MRA and DSA in the overall aneurysm size (calculated as the mean from height/width/neck) ( P = 0.178), as well as in the mean width ( P = 0.778) and neck values ( P = 0.190). The mean height was significantly larger in 0.55 T TOF MRA in comparison to DSA ( P = 0.020). Intermodality (1.5/3 T TOF MRA) and interrater agreement were excellent (ICC > 0.94). Of the 32 data sets of patients with and without IA, the blinded reader detected all aneurysms correctly by using 0.55 T images. CONCLUSIONS TOF-MRA acquired with a modern 0.55 T MRI is a reliable tool for the detection and initial assessment of IAs.
Collapse
|
9
|
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.
Collapse
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.)
| |
Collapse
|
10
|
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.
Collapse
|
11
|
Platt T, Ladd ME, Paech D. 7 Tesla and Beyond: Advanced Methods and Clinical Applications in Magnetic Resonance Imaging. Invest Radiol 2021; 56:705-725. [PMID: 34510098 PMCID: PMC8505159 DOI: 10.1097/rli.0000000000000820] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 08/07/2021] [Accepted: 08/07/2021] [Indexed: 12/15/2022]
Abstract
ABSTRACT Ultrahigh magnetic fields offer significantly higher signal-to-noise ratio, and several magnetic resonance applications additionally benefit from a higher contrast-to-noise ratio, with static magnetic field strengths of B0 ≥ 7 T currently being referred to as ultrahigh fields (UHFs). The advantages of UHF can be used to resolve structures more precisely or to visualize physiological/pathophysiological effects that would be difficult or even impossible to detect at lower field strengths. However, with these advantages also come challenges, such as inhomogeneities applying standard radiofrequency excitation techniques, higher energy deposition in the human body, and enhanced B0 field inhomogeneities. The advantages but also the challenges of UHF as well as promising advanced methodological developments and clinical applications that particularly benefit from UHF are discussed in this review article.
Collapse
Affiliation(s)
- Tanja Platt
- From the Medical Physics in Radiology, German Cancer Research Center (DKFZ)
| | - Mark E. Ladd
- From the Medical Physics in Radiology, German Cancer Research Center (DKFZ)
- Faculty of Physics and Astronomy
- Faculty of Medicine, University of Heidelberg, Heidelberg
- Erwin L. Hahn Institute for MRI, University of Duisburg-Essen, Essen
| | - Daniel Paech
- Division of Radiology, German Cancer Research Center (DKFZ), Heidelberg
- Clinic for Neuroradiology, University of Bonn, Bonn, Germany
| |
Collapse
|
12
|
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.
Collapse
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
| |
Collapse
|
13
|
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.
Collapse
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.
| |
Collapse
|
14
|
Comparing methods of detecting and segmenting unruptured intracranial aneurysms on TOF-MRAS: The ADAM challenge. Neuroimage 2021; 238:118216. [PMID: 34052465 DOI: 10.1016/j.neuroimage.2021.118216] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 05/11/2021] [Accepted: 05/26/2021] [Indexed: 11/24/2022] Open
Abstract
Accurate detection and quantification of unruptured intracranial aneurysms (UIAs) is important for rupture risk assessment and to allow an informed treatment decision to be made. Currently, 2D manual measures used to assess UIAs on Time-of-Flight magnetic resonance angiographies (TOF-MRAs) lack 3D information and there is substantial inter-observer variability for both aneurysm detection and assessment of aneurysm size and growth. 3D measures could be helpful to improve aneurysm detection and quantification but are time-consuming and would therefore benefit from a reliable automatic UIA detection and segmentation method. The Aneurysm Detection and segMentation (ADAM) challenge was organised in which methods for automatic UIA detection and segmentation were developed and submitted to be evaluated on a diverse clinical TOF-MRA dataset. A training set (113 cases with a total of 129 UIAs) was released, each case including a TOF-MRA, a structural MR image (T1, T2 or FLAIR), annotation of any present UIA(s) and the centre voxel of the UIA(s). A test set of 141 cases (with 153 UIAs) was used for evaluation. Two tasks were proposed: (1) detection and (2) segmentation of UIAs on TOF-MRAs. Teams developed and submitted containerised methods to be evaluated on the test set. Task 1 was evaluated using metrics of sensitivity and false positive count. Task 2 was evaluated using dice similarity coefficient, modified hausdorff distance (95th percentile) and volumetric similarity. For each task, a ranking was made based on the average of the metrics. In total, eleven teams participated in task 1 and nine of those teams participated in task 2. Task 1 was won by a method specifically designed for the detection task (i.e. not participating in task 2). Based on segmentation metrics, the top two methods for task 2 performed statistically significantly better than all other methods. The detection performance of the top-ranking methods was comparable to visual inspection for larger aneurysms. Segmentation performance of the top ranking method, after selection of true UIAs, was similar to interobserver performance. The ADAM challenge remains open for future submissions and improved submissions, with a live leaderboard to provide benchmarking for method developments at https://adam.isi.uu.nl/.
Collapse
|
15
|
Stotesbury H, Kawadler JM, Saunders DE, Kirkham FJ. MRI detection of brain abnormality in sickle cell disease. Expert Rev Hematol 2021; 14:473-491. [PMID: 33612034 PMCID: PMC8315209 DOI: 10.1080/17474086.2021.1893687] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 02/18/2021] [Indexed: 02/08/2023]
Abstract
Introduction: Over the past decades, neuroimaging studies have clarified that a significant proportion of patients with sickle cell disease (SCD) have functionally significant brain abnormalities. Clinically, structural magnetic resonance imaging (MRI) sequences (T2, FLAIR, diffusion-weighted imaging) have been used by radiologists to diagnose chronic and acute cerebral infarction (both overt and clinically silent), while magnetic resonance angiography and venography have been used to diagnose arteriopathy and venous thrombosis. In research settings, imaging scientists are increasingly applying quantitative techniques to shine further light on underlying mechanisms.Areas covered: From a June 2020 PubMed search of 'magnetic' or 'MRI' and 'sickle' over the previous 5 years, we selected manuscripts on T1-based morphometric analysis, diffusion tensor imaging, arterial spin labeling, T2-oximetry, quantitative susceptibility, and connectivity.Expert Opinion: Quantitative MRI techniques are identifying structural and hemodynamic biomarkers associated with risk of neurological and neurocognitive complications. A growing body of evidence suggests that these biomarkers are sensitive to change with treatments, such as blood transfusion and hydroxyurea, indicating that they may hold promise as endpoints in future randomized clinical trials of novel approaches including hemoglobin F upregulation, reduction of polymerization, and gene therapy. With further validation, such techniques may eventually also improve neurological and neurocognitive risk stratification in this vulnerable population.
Collapse
Affiliation(s)
- Hanne Stotesbury
- Developmental Neurosciences Section, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Jamie Michelle Kawadler
- Developmental Neurosciences Section, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Dawn Elizabeth Saunders
- Developmental Neurosciences Section, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Fenella Jane Kirkham
- Developmental Neurosciences Section, UCL Great Ormond Street Institute of Child Health, London, UK
| |
Collapse
|
16
|
Salih M, Harris D, Moore J, Thomas A, Ogilvy CS. Current Management of Small Unruptured Intracranial Aneurysms in the United States: Results of a National Survey. World Neurosurg 2020; 146:e631-e638. [PMID: 33152491 DOI: 10.1016/j.wneu.2020.10.149] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Revised: 10/26/2020] [Accepted: 10/27/2020] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To understand how physicians in the United States manage patients with small unruptured intracranial aneurysms and factors that influence the management. METHODS An online survey questionnaire was designed through SurveyMonkey and distributed electronically to The Society of Interventional Surgery, American Association of Neurological Surgeons/Congress of Neurological Surgeons Joint Section of Cerebrovascular Surgery, American Academy of Neurology, and Massachusetts Neurologic Association. All participations were voluntary and anonymous. RESULTS Among all the participants, 53.8% of them were neurosurgeons, 33.0% were neurointerventional radiologists, and 13.2% were neurologists. For management of aneurysms 2-4 mm, 87.8% of respondents favored routine surveillance with imaging follow-up, 3.8% preferred routine treatment, and 8.5% recommended routine treatment or follow-up only for high risk patients. In total, 25.5% preferred annual follow-up, and 67.9% liked follow-up once in a year and then space out at various intervals. For aneurysms between 5 and 7 mm, 73.6% supported routine treatment, 20.8% favored surveillance with imaging follow-up, and 5.7% recommended treating or follow-up only high-risk groups. In total, 58.5% preferred annual follow-up, whereas 34.9% liked follow-up once in a year and then space out at various intervals. For routine follow-up, 64.1% of the physicians chose magnetic resonance angiography without contrast, and 40.6% preferred computed tomography angiography. CONCLUSIONS For aneurysms 2-4 mm, majority of the physicians preferred regular follow-up, whereas for aneurysms 5-7 mm, the majority favor treatment. There remains heterogeneity in practice among physicians in the United States regarding follow-up strategies for small unruptured aneurysms. Further studies are needed to evaluate the optimal management strategy, follow-up frequency and duration of imaging for small unruptured intracranial aneurysms.
Collapse
Affiliation(s)
- Mira Salih
- Neurosurgical Service, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.
| | - Dominic Harris
- Neurosurgical Service, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Justin Moore
- Neurosurgical Service, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Ajith Thomas
- Neurosurgical Service, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Christopher S Ogilvy
- Neurosurgical Service, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
17
|
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.
Collapse
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.)
| |
Collapse
|
18
|
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.
Collapse
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
| |
Collapse
|
19
|
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.
Collapse
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
| |
Collapse
|
20
|
Noureddine Y, Kraff O, Ladd ME, Wrede K, Chen B, Quick HH, Schaefers G, Bitz AK. Radiofrequency induced heating around aneurysm clips using a generic birdcage head coil at 7 Tesla under consideration of the minimum distance to decouple multiple aneurysm clips. Magn Reson Med 2019; 82:1859-1875. [DOI: 10.1002/mrm.27835] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 05/08/2019] [Accepted: 05/10/2019] [Indexed: 12/13/2022]
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, German Cancer Research Center (DKFZ) Heidelberg Germany
- Faculty of Physics and Astronomy and Faculty of Medicine University of Heidelberg Heidelberg Germany
| | - Karsten 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, 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
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ) Heidelberg Germany
- Faculty of Electrical Engineering and Information Technology FH Aachen University of Applied Sciences Aachen NRW Germany
| |
Collapse
|
21
|
Herzberg M, Forbrig R, Schichor C, Brückmann H, Dorn F. Preoperative Digital Subtraction Angiography in Incidental Unruptured Intracranial Aneurysms. Clin Neuroradiol 2018; 28:429-435. [DOI: 10.1007/s00062-018-0689-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 04/04/2018] [Indexed: 11/24/2022]
|
22
|
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.
Collapse
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
| |
Collapse
|
23
|
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.
Collapse
|
24
|
Raval SB, Britton CA, Zhao T, Krishnamurthy N, Santini T, Gorantla VS, Ibrahim TS. Ultra-high field upper extremity peripheral nerve and non-contrast enhanced vascular imaging. PLoS One 2017; 12:e0175629. [PMID: 28662061 PMCID: PMC5490941 DOI: 10.1371/journal.pone.0175629] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Accepted: 03/29/2017] [Indexed: 01/05/2023] Open
Abstract
OBJECTIVE The purpose of this study was to explore the efficacy of Ultra-high field [UHF] 7 Tesla [T] MRI as compared to 3T MRI in non-contrast enhanced [nCE] imaging of structural anatomy in the elbow, forearm, and hand [upper extremity]. MATERIALS AND METHOD A wide range of sequences including T1 weighted [T1] volumetric interpolate breath-hold exam [VIBE], T2 weighted [T2] double-echo steady state [DESS], susceptibility weighted imaging [SWI], time-of-flight [TOF], diffusion tensor imaging [DTI], and diffusion spectrum imaging [DSI] were optimized and incorporated with a radiofrequency [RF] coil system composed of a transverse electromagnetic [TEM] transmit coil combined with an 8-channel receive-only array for 7T upper extremity [UE] imaging. In addition, Siemens optimized protocol/sequences were used on a 3T scanner and the resulting images from T1 VIBE and T2 DESS were compared to that obtained at 7T qualitatively and quantitatively [SWI was only qualitatively compared]. DSI studio was utilized to identify nerves based on analysis of diffusion weighted derived fractional anisotropy images. Images of forearm vasculature were extracted using a paint grow manual segmentation method based on MIPAV [Medical Image Processing, Analysis, and Visualization]. RESULTS High resolution and high quality signal-to-noise ratio [SNR] and contrast-to-noise ratio [CNR]-images of the hand, forearm, and elbow were acquired with nearly homogeneous 7T excitation. Measured [performed on the T1 VIBE and T2 DESS sequences] SNR and CNR values were almost doubled at 7T vs. 3T. Cartilage, synovial fluid and tendon structures could be seen with higher clarity in the 7T T1 and T2 weighted images. SWI allowed high resolution and better quality imaging of large and medium sized arteries and veins, capillary networks and arteriovenous anastomoses at 7T when compared to 3T. 7T diffusion weighted sequence [not performed at 3T] demonstrates that the forearm nerves are clearly delineated by fiber tractography. The proper digital palmar arteries and superficial palmar arch could also be clearly visualized using TOF nCE 7T MRI. CONCLUSION Ultra-high resolution neurovascular imaging in upper extremities is possible at 7T without use of renal toxic intravenous contrast. 7T MRI can provide superior peripheral nerve [based on fiber anisotropy and diffusion coefficient parameters derived from diffusion tensor/spectrum imaging] and vascular [nCE MRA and vessel segmentation] imaging.
Collapse
Affiliation(s)
- Shailesh B. Raval
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pittsburgh, United States of America
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pittsburgh, United States of America
| | - Cynthia A. Britton
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pittsburgh, United States of America
| | - Tiejun Zhao
- Siemens Medical Solutions, New York, United States of America
| | - Narayanan Krishnamurthy
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pittsburgh, United States of America
| | - Tales Santini
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pittsburgh, United States of America
| | - Vijay S. Gorantla
- Department of Plastic Surgery, Pittsburgh, Pittsburgh, United States of America
- * E-mail: (TSI); (VSG)
| | - Tamer S. Ibrahim
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pittsburgh, United States of America
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pittsburgh, United States of America
- * E-mail: (TSI); (VSG)
| |
Collapse
|
25
|
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
| |
Collapse
|
26
|
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
| |
Collapse
|