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Lang M, Clifford B, Lo WC, Applewhite BP, Tabari A, Filho ALMG, Hosseini Z, Longo MGF, Cauley SF, Setsompop K, Bilgic B, Feiweier T, Lev MH, Schaefer PW, Rapalino O, Huang SY, Conklin J. Clinical Evaluation of a 2-Minute Ultrafast Brain MR Protocol for Evaluation of Acute Pathology in the Emergency and Inpatient Settings. AJNR Am J Neuroradiol 2024; 45:379-385. [PMID: 38453413 DOI: 10.3174/ajnr.a8143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 12/07/2023] [Indexed: 03/09/2024]
Abstract
BACKGROUND AND PURPOSE The use of MR imaging in emergency settings has been limited by availability, long scan times, and sensitivity to motion. This study assessed the diagnostic performance of an ultrafast brain MR imaging protocol for evaluation of acute intracranial pathology in the emergency department and inpatient settings. MATERIALS AND METHODS Sixty-six adult patients who underwent brain MR imaging in the emergency department and inpatient settings were included in the study. All patients underwent both the reference and the ultrafast brain MR protocols. Both brain MR imaging protocols consisted of T1-weighted, T2/T2*-weighted, FLAIR, and DWI sequences. The ultrafast MR images were reconstructed by using a machine-learning assisted framework. All images were reviewed by 2 blinded neuroradiologists. RESULTS The average acquisition time was 2.1 minutes for the ultrafast brain MR protocol and 10 minutes for the reference brain MR protocol. There was 98.5% agreement on the main clinical diagnosis between the 2 protocols. In head-to-head comparison, the reference protocol was preferred in terms of image noise and geometric distortion (P < .05 for both). The ultrafast ms-EPI protocol was preferred over the reference protocol in terms of reduced motion artifacts (P < .01). Overall diagnostic quality was not significantly different between the 2 protocols (P > .05). CONCLUSIONS The ultrafast brain MR imaging protocol provides high accuracy for evaluating acute pathology while only requiring a fraction of the scan time. Although there was greater image noise and geometric distortion on the ultrafast brain MR protocol images, there was significant reduction in motion artifacts with similar overall diagnostic quality between the 2 protocols.
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Affiliation(s)
- Min Lang
- From the Department of Radiology (M.L., B.P.A., A.T., M.G.F.L., M.H.L., P.W.S., O.R., S.Y.H., J.C.), Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School (M.L., B.P.A., A.T., M.G.F.L., M.H.L., P.W.S., O.R., S.Y.H., J.C.), Boston, Massachusetts
| | - Bryan Clifford
- Siemens Medical Solutions (B.C., W.-C.L., Z.H., S.F.C.), Boston, Massachusetts
| | - Wei-Ching Lo
- Siemens Medical Solutions (B.C., W.-C.L., Z.H., S.F.C.), Boston, Massachusetts
| | - Brooks P Applewhite
- From the Department of Radiology (M.L., B.P.A., A.T., M.G.F.L., M.H.L., P.W.S., O.R., S.Y.H., J.C.), Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School (M.L., B.P.A., A.T., M.G.F.L., M.H.L., P.W.S., O.R., S.Y.H., J.C.), Boston, Massachusetts
| | - Azadeh Tabari
- From the Department of Radiology (M.L., B.P.A., A.T., M.G.F.L., M.H.L., P.W.S., O.R., S.Y.H., J.C.), Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School (M.L., B.P.A., A.T., M.G.F.L., M.H.L., P.W.S., O.R., S.Y.H., J.C.), Boston, Massachusetts
| | | | - Zahra Hosseini
- Siemens Medical Solutions (B.C., W.-C.L., Z.H., S.F.C.), Boston, Massachusetts
| | - Maria Gabriela Figueiro Longo
- From the Department of Radiology (M.L., B.P.A., A.T., M.G.F.L., M.H.L., P.W.S., O.R., S.Y.H., J.C.), Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School (M.L., B.P.A., A.T., M.G.F.L., M.H.L., P.W.S., O.R., S.Y.H., J.C.), Boston, Massachusetts
| | - Stephen F Cauley
- Siemens Medical Solutions (B.C., W.-C.L., Z.H., S.F.C.), Boston, Massachusetts
- Harvard-MIT Health Sciences and Technology (S.F.C., B.B., S.Y.H.), Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Kawin Setsompop
- Departments of Radiology and Electrical Engineering (K.S.), Stanford University, Stanford, California
| | - Berkin Bilgic
- Harvard-MIT Health Sciences and Technology (S.F.C., B.B., S.Y.H.), Massachusetts Institute of Technology, Cambridge, Massachusetts
| | | | - Michael H Lev
- From the Department of Radiology (M.L., B.P.A., A.T., M.G.F.L., M.H.L., P.W.S., O.R., S.Y.H., J.C.), Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School (M.L., B.P.A., A.T., M.G.F.L., M.H.L., P.W.S., O.R., S.Y.H., J.C.), Boston, Massachusetts
| | - Pamela W Schaefer
- From the Department of Radiology (M.L., B.P.A., A.T., M.G.F.L., M.H.L., P.W.S., O.R., S.Y.H., J.C.), Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School (M.L., B.P.A., A.T., M.G.F.L., M.H.L., P.W.S., O.R., S.Y.H., J.C.), Boston, Massachusetts
| | - Otto Rapalino
- From the Department of Radiology (M.L., B.P.A., A.T., M.G.F.L., M.H.L., P.W.S., O.R., S.Y.H., J.C.), Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School (M.L., B.P.A., A.T., M.G.F.L., M.H.L., P.W.S., O.R., S.Y.H., J.C.), Boston, Massachusetts
| | - Susie Y Huang
- From the Department of Radiology (M.L., B.P.A., A.T., M.G.F.L., M.H.L., P.W.S., O.R., S.Y.H., J.C.), Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School (M.L., B.P.A., A.T., M.G.F.L., M.H.L., P.W.S., O.R., S.Y.H., J.C.), Boston, Massachusetts
- Harvard-MIT Health Sciences and Technology (S.F.C., B.B., S.Y.H.), Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - John Conklin
- From the Department of Radiology (M.L., B.P.A., A.T., M.G.F.L., M.H.L., P.W.S., O.R., S.Y.H., J.C.), Massachusetts General Hospital, Boston, Massachusetts
- Harvard Medical School (M.L., B.P.A., A.T., M.G.F.L., M.H.L., P.W.S., O.R., S.Y.H., J.C.), Boston, Massachusetts
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Ganesh VKSV, Kamepalli HK, Sharma DP, Thomas B, Kesavadas C. Multi-contrast echo-planar imaging sequence (Echo-planar imaging mix) in clinical situations demanding faster MRI-brain scans. J Neurosci Rural Pract 2024; 15:341-348. [PMID: 38746507 PMCID: PMC11090545 DOI: 10.25259/jnrp_508_2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Accepted: 03/10/2024] [Indexed: 05/16/2024] Open
Abstract
Objectives The excellent resolution offered by magnetic resonance imaging (MRI) has a trade-off in the form of scan duration. The purpose of the present study was to assess the clinical utility of echo-planar imaging mix (EPIMix), an echo-planar imaging-based MRI sequence for the brain with a short acquisition time. Materials and Methods This was a retrospective observational study of 50 patients, who could benefit from faster MRI brain scans. The T1, T2, fluid attenuated inversion recovery, diffusion-weighted imaging (DWI), and T2*/susceptibility-weighted imaging sequences were acquired, conventionally and with EPIMix. Conventional and EPIMix images were assessed by two radiologists for overall quality, motion, and susceptibility artifacts and scored on a Likert scale. The scores given for conventional and EPIMix images were compared. The diagnostic performance of EPIMix was also assessed by the ability to detect clinically relevant findings. Results The acquisition time for conventional MRI was 11 min and 45 s and for EPIMix 1 min and 15 s. All EPIMix images were sufficient for diagnostic use. On assessment of the diagnostic performance, it was excellent for ischemic and hemorrhagic strokes. Smaller lesions, lesions adjacent to bone, and post-operative tumors were difficult to identify. Moderate to perfect agreement (Kappa values 0.41-1) was seen between radiologists for all categories except skull base, calvarial, and orbital lesions. Image quality, artifact assessment showed excellent interobserver agreement (>90%) for the scores. All EPIMix images showed reduced motion artifacts. The EPIMix-DWI was comparable to conventional-DWI in terms of quality and artifacts. The remaining sequences showed reduced quality and increased susceptibility. Conclusion The EPIMix has a significantly reduced acquisition time than conventional MRI and could be used instead of conventional MRI in situations demanding faster scans such as suspected acute ischemic or hemorrhagic stroke. In other clinical scenarios, it could help tailor the MRI examination for each patient.
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Affiliation(s)
- Viswanadh Kalaparti Sri Venkata Ganesh
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India
| | - Hari Kishore Kamepalli
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India
| | | | - Bejoy Thomas
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India
| | - Chandrasekharan Kesavadas
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India
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De Luca F, Kits A, Martin Muñoz D, Aspelin Å, Kvist O, Österman Y, Diaz Ruiz S, Skare S, Falk Delgado A. Elective one-minute full brain multi-contrast MRI versus brain CT in pediatric patients: a prospective feasibility study. BMC Med Imaging 2024; 24:23. [PMID: 38267889 PMCID: PMC10809606 DOI: 10.1186/s12880-024-01196-6] [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] [Received: 06/15/2023] [Accepted: 01/08/2024] [Indexed: 01/26/2024] Open
Abstract
BACKGROUND Brain CT can be used to evaluate pediatric patients with suspicion of cerebral pathology when anesthetic and MRI resources are scarce. This study aimed to assess if pediatric patients referred for an elective brain CT could endure a diagnostic fast brain MRI without general anesthesia using a one-minute multi-contrast EPI-based sequence (EPIMix) with comparable diagnostic performance. METHODS Pediatric patients referred for an elective brain CT between March 2019 and March 2020 were prospectively included and underwent EPIMix without general anesthesia in addition to CT. Three readers (R1-3) independently evaluated EPIMix and CT images on two separate occasions. The two main study outcomes were the tolerance to undergo an EPIMix scan without general anesthesia and its performance to classify a scan as normal or abnormal. Secondary outcomes were assessment of disease category, incidental findings, diagnostic image quality, diagnostic confidence, and image artifacts. Further, a side-by-side evaluation of EPIMix and CT was performed. The signal-to-noise ratio (SNR) was calculated for EPIMix on T1-weighted, T2-weighted, and ADC images. Descriptive statistics, Fisher's exact test, and Chi-squared test were used to compare the two imaging modalities. RESULTS EPIMix was well tolerated by all included patients (n = 15) aged 5-16 (mean 11, SD 3) years old. Thirteen cases on EPIMix and twelve cases on CT were classified as normal by all readers (R1-3), while two cases on EPIMix and three cases on CT were classified as abnormal by one reader (R1), (R1-3, p = 1.00). There was no evidence of a difference in diagnostic confidence, image quality, or the presence of motion artifacts between EPIMix and CT (R1-3, p ≥ 0.10). Side-by-side evaluation (R2 + R4 + R5) reviewed all scans as lacking significant pathological findings on EPIMix and CT images. CONCLUSIONS Full brain MRI-based EPIMix sequence was well tolerated without general anesthesia with a diagnostic performance comparable to CT in elective pediatric patients. TRIAL REGISTRATION This study was approved by the Swedish Ethical Review Authority (ethical approval number/ID Ethical approval 2017/2424-31/1). This study was a clinical trial study, with study protocol published at ClinicalTrials.gov with Trial registration number NCT03847051, date of registration 18/02/2019.
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Affiliation(s)
- Francesca De Luca
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden.
- Department of Radiology, Karolinska University Hospital, Stockholm, Sweden.
| | - Annika Kits
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
- Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Daniel Martin Muñoz
- Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Åsa Aspelin
- Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Ola Kvist
- Department of Pediatric Radiology, Karolinska University Hospital, Stockholm, Sweden
- Department of Women's and Children's Health, Karolinska Institute, Stockholm, Sweden
| | - Yords Österman
- Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Sandra Diaz Ruiz
- Department of Pediatric Radiology, Karolinska University Hospital, Stockholm, Sweden
- Department of Women's and Children's Health, Karolinska Institute, Stockholm, Sweden
- Department of Radiology, Lund University, Lund, Sweden
| | - Stefan Skare
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
- Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Anna Falk Delgado
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
- Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
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Eisenmenger LB, Peret A, Roberts GS, Spahic A, Tang C, Kuner AD, Grayev AM, Field AS, Rowley HA, Kennedy TA. Focused Abbreviated Survey MRI Protocols for Brain and Spine Imaging. Radiographics 2023; 43:e220147. [PMID: 37167089 PMCID: PMC10262597 DOI: 10.1148/rg.220147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 10/12/2022] [Accepted: 10/18/2022] [Indexed: 05/13/2023]
Abstract
There has been extensive growth in both the technical development and the clinical applications of MRI, establishing this modality as one of the most powerful diagnostic imaging tools. However, long examination and image interpretation times still limit the application of MRI, especially in emergent clinical settings. Rapid and abbreviated MRI protocols have been developed as alternatives to standard MRI, with reduced imaging times, and in some cases limited numbers of sequences, to more efficiently answer specific clinical questions. A group of rapid MRI protocols used at the authors' institution, referred to as FAST (focused abbreviated survey techniques), are designed to include or exclude emergent or urgent conditions or screen for specific entities. These FAST protocols provide adequate diagnostic image quality with use of accelerated approaches to produce imaging studies faster than traditional methods. FAST protocols have become critical diagnostic screening tools at the authors' institution, allowing confident and efficient confirmation or exclusion of actionable findings. The techniques commonly used to reduce imaging times, the imaging protocols used at the authors' institution, and future directions in FAST imaging are reviewed to provide a practical and comprehensive overview of FAST MRI for practicing neuroradiologists. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.
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Affiliation(s)
| | | | - Grant S. Roberts
- From the Departments of Radiology (L.B.E., A.P., A.D.K., A.M.G.,
A.S.F., H.A.R., T.A.K.) and Medical Physics (G.S.R., A.S., C.T.), University of
Wisconsin School of Medicine and Public Health, 600 Highland Ave, Madison, WI
53792-3252
| | - Alma Spahic
- From the Departments of Radiology (L.B.E., A.P., A.D.K., A.M.G.,
A.S.F., H.A.R., T.A.K.) and Medical Physics (G.S.R., A.S., C.T.), University of
Wisconsin School of Medicine and Public Health, 600 Highland Ave, Madison, WI
53792-3252
| | - Chenwei Tang
- From the Departments of Radiology (L.B.E., A.P., A.D.K., A.M.G.,
A.S.F., H.A.R., T.A.K.) and Medical Physics (G.S.R., A.S., C.T.), University of
Wisconsin School of Medicine and Public Health, 600 Highland Ave, Madison, WI
53792-3252
| | - Anthony D. Kuner
- From the Departments of Radiology (L.B.E., A.P., A.D.K., A.M.G.,
A.S.F., H.A.R., T.A.K.) and Medical Physics (G.S.R., A.S., C.T.), University of
Wisconsin School of Medicine and Public Health, 600 Highland Ave, Madison, WI
53792-3252
| | - Allison M. Grayev
- From the Departments of Radiology (L.B.E., A.P., A.D.K., A.M.G.,
A.S.F., H.A.R., T.A.K.) and Medical Physics (G.S.R., A.S., C.T.), University of
Wisconsin School of Medicine and Public Health, 600 Highland Ave, Madison, WI
53792-3252
| | - Aaron S. Field
- From the Departments of Radiology (L.B.E., A.P., A.D.K., A.M.G.,
A.S.F., H.A.R., T.A.K.) and Medical Physics (G.S.R., A.S., C.T.), University of
Wisconsin School of Medicine and Public Health, 600 Highland Ave, Madison, WI
53792-3252
| | - Howard A. Rowley
- From the Departments of Radiology (L.B.E., A.P., A.D.K., A.M.G.,
A.S.F., H.A.R., T.A.K.) and Medical Physics (G.S.R., A.S., C.T.), University of
Wisconsin School of Medicine and Public Health, 600 Highland Ave, Madison, WI
53792-3252
| | - Tabassum A. Kennedy
- From the Departments of Radiology (L.B.E., A.P., A.D.K., A.M.G.,
A.S.F., H.A.R., T.A.K.) and Medical Physics (G.S.R., A.S., C.T.), University of
Wisconsin School of Medicine and Public Health, 600 Highland Ave, Madison, WI
53792-3252
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Verclytte S, Gnanih R, Verdun S, Feiweier T, Clifford B, Ambarki K, Pasquini M, Ding J. Ultrafast MRI using deep learning echoplanar imaging for a comprehensive assessment of acute ischemic stroke. Eur Radiol 2023; 33:3715-3725. [PMID: 36928567 DOI: 10.1007/s00330-023-09508-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 12/09/2022] [Accepted: 01/30/2023] [Indexed: 03/18/2023]
Abstract
OBJECTIVES Acute ischemic stroke (AIS) is an emergency requiring both fast and informative MR sequences. We aimed to assess the performance of an artificial intelligence-enhanced ultrafast (UF) protocol, compared to the reference protocol, in the AIS management. METHODS We included patients admitted in the emergency department for suspected AIS. Each patient underwent a 3-T MR protocol, including reference acquisitions of T2-FLAIR, DWI, and SWI (duration: 7 min 54 s) and their accelerated multishot EPI counterparts for T2-FLAIR and T2*, complemented by a single-shot EPI DWI (duration: 1 min 54 s). Two blinded neuroradiologists reviewed each dataset, assessing DWI (detection, location, number of acute lesions), FLAIR (vascular hyperintensities, visibility of acute lesions), and SWI/T2* (hemorrhagic transformation, thrombus). We compared the agreement between the diagnoses obtained with both protocols using kappa coefficients. RESULTS A total of 173 patients were included consecutively, of whom 80 with an AIS in DWI. We found an almost perfect agreement between the UF and reference protocols regarding the detection, distribution, number of AIS in DWI (κ = 0.98, 0.98, and 0.87 respectively), the presence of vascular hyperintensities, and the presence of a parenchymal hyperintensity in the AIS region in FLAIR (κ = 0.93 and 0.89 respectively). Agreement was substantial in T2*/SWI for thrombus detection, and fair for hemorrhagic transformation detection (κ = 0.64 and 0.38 respectively). Differential diagnoses were similarly detected by both protocols (κ = 1). CONCLUSIONS Our AI-enhanced ultrafast MRI protocol allowed an effective detection and characterization of both AIS and differential diagnoses in less than 2 min. KEY POINTS • The AI-enhanced ultrafast MRI protocol allowed an effective detection of acute stroke. • Characterization of stroke features with the UF protocol was equivalent to the reference sequences. • Differential diagnoses were detected similarly by the UF and reference protocols.
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Affiliation(s)
- Sebastien Verclytte
- Imaging Department, Lille Catholic Hospitals, Lille Catholic University, F-59000, Lille, France.
| | - Robin Gnanih
- Imaging Department, Lille Catholic Hospitals, Lille Catholic University, F-59000, Lille, France
| | - Stephane Verdun
- Biostatistics Department - Delegation for Clinical Research and Innovation, Lille Catholic Hospitals, Lille Catholic University, F-59000, Lille, France
| | | | | | | | - Marta Pasquini
- Department of Neurology, Lille Catholic Hospitals, Lille Catholic University, F-59000, Lille, France
| | - Juliette Ding
- Imaging Department, Lille Catholic Hospitals, Lille Catholic University, F-59000, Lille, France
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Pinter NK. The Right Imaging Protocol for the Right Patient. Continuum (Minneap Minn) 2023; 29:16-26. [PMID: 36795871 DOI: 10.1212/con.0000000000001209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
OBJECTIVE This article provides a high-level overview of the challenge of choosing the right imaging approach for an individual patient. It also presents a generalizable approach that can be applied to practice regardless of specific imaging technologies. ESSENTIAL POINTS This article constitutes an introduction to the in-depth, topic-focused analyses in the rest of this issue. It examines the broad principles that guide placing a patient on the right diagnostic trajectory, illustrated with real-life examples of current protocol recommendations and cases of advanced imaging techniques, as well as some thought experiments. Thinking about diagnostic imaging strictly in terms of imaging protocols is often inefficient because these protocols can be vague and have numerous variations. Broadly defined protocols may be sufficient, but their successful use often depends largely on the particular circumstances, with special emphasis on the relationship between neurologists and radiologists.
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Gallo-Bernal S, Bedoya MA, Gee MS, Jaimes C. Pediatric magnetic resonance imaging: faster is better. Pediatr Radiol 2022:10.1007/s00247-022-05529-x. [PMID: 36261512 DOI: 10.1007/s00247-022-05529-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 08/29/2022] [Accepted: 10/03/2022] [Indexed: 10/24/2022]
Abstract
Magnetic resonance imaging (MRI) has emerged as the preferred imaging modality for evaluating a wide range of pediatric medical conditions. Nevertheless, the long acquisition times associated with this technique can limit its widespread use in young children, resulting in motion-degraded or non-diagnostic studies. As a result, sedation or general anesthesia is often necessary to obtain diagnostic images, which has implications for the safety profile of MRI, the cost of the exam and the radiology department's clinical workflow. Over the last decade, several techniques have been developed to increase the speed of MRI, including parallel imaging, single-shot acquisition, controlled aliasing techniques, compressed sensing and artificial-intelligence-based reconstructions. These are advantageous because shorter examinations decrease the need for sedation and the severity of motion artifacts, increase scanner throughput, and improve system efficiency. In this review we discuss a framework for image acceleration in children that includes the synergistic use of state-of-the-art MRI hardware and optimized pulse sequences. The discussion is framed within the context of pediatric radiology and incorporates the authors' experience in deploying these techniques in routine clinical practice.
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Affiliation(s)
- Sebastian Gallo-Bernal
- Department of Radiology, Massachusetts General Hospital, Boston, MA, USA.,Department of Radiology, Harvard Medical School, Boston, MA, USA
| | - M Alejandra Bedoya
- Department of Radiology, Harvard Medical School, Boston, MA, USA.,Department of Radiology, Boston Children's Hospital, 300 Longwood Ave., 2nd floor, Main Building, Boston, MA, 02115, USA
| | - Michael S Gee
- Department of Radiology, Massachusetts General Hospital, Boston, MA, USA.,Department of Radiology, Harvard Medical School, Boston, MA, USA
| | - Camilo Jaimes
- Department of Radiology, Harvard Medical School, Boston, MA, USA. .,Department of Radiology, Boston Children's Hospital, 300 Longwood Ave., 2nd floor, Main Building, Boston, MA, 02115, USA.
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8
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How can imaging in acute ischemic stroke help us to understand tissue fate in the era of endovascular treatment and cerebroprotection? Neuroradiology 2022; 64:1697-1707. [PMID: 35854136 DOI: 10.1007/s00234-022-03001-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 06/21/2022] [Indexed: 10/17/2022]
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Lang M, Rapalino O, Huang S, Lev MH, Conklin J, Wald LL. Emerging Techniques and Future Directions: Fast and Portable Magnetic Resonance Imaging. Magn Reson Imaging Clin N Am 2022; 30:565-582. [PMID: 35995480 DOI: 10.1016/j.mric.2022.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Fast MRI and portable MRI are emerging as promising technologies to improve the speed, efficiency, and availability of MR imaging. Fast MRI methods are increasingly being adopted to create screening protocols for the diagnosis and management of acute pathology in the emergency department. Faster imaging can facilitate timely diagnosis, reduce motion artifacts, and improve departmental MR operations. Point-of-care and portable MRI are emerging technologies that require radiologists to reenvision the role of MRI as a tool with greater accessibility, fewer siting constraints, and the ability to provide valuable diagnostic information at the bedside. Recently introduced commercially available pulse sequences and new MRI scanners are bringing these technologies closer to the patient's clinical setting, and we expect their use to only increase over the coming decade. This article provides an overview of these emerging technologies for emergency radiologists.
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Affiliation(s)
- Min Lang
- Department of Radiology, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
| | - Otto Rapalino
- Department of Radiology, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
| | - Susie Huang
- Department of Radiology, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA; Athinoula A. Martinos Center for Biomedical Imaging, 149 13th Street, Charleston, MA 02129, USA
| | - Michael H Lev
- Department of Radiology, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
| | - John Conklin
- Department of Radiology, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA.
| | - Lawrence L Wald
- Department of Radiology, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA; Athinoula A. Martinos Center for Biomedical Imaging, 149 13th Street, Charleston, MA 02129, USA
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Hobday H, Cole JH, Stanyard RA, Daws RE, Giampietro V, O'Daly O, Leech R, Váša F. Tissue volume estimation and age prediction using rapid structural brain scans. Sci Rep 2022; 12:12005. [PMID: 35835813 PMCID: PMC9283414 DOI: 10.1038/s41598-022-14904-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 06/14/2022] [Indexed: 11/30/2022] Open
Abstract
The multicontrast EPImix sequence generates six contrasts, including a T1-weighted scan, in ~1 min. EPImix shows comparable diagnostic performance to conventional scans under qualitative clinical evaluation, and similarities in simple quantitative measures including contrast intensity. However, EPImix scans have not yet been compared to standard MRI scans using established quantitative measures. In this study, we compared conventional and EPImix-derived T1-weighted scans of 64 healthy participants using tissue volume estimates and predicted brain-age. All scans were pre-processed using the SPM12 DARTEL pipeline, generating measures of grey matter, white matter and cerebrospinal fluid volume. Brain-age was predicted using brainageR, a Gaussian Processes Regression model previously trained on a large sample of standard T1-weighted scans. Estimates of both global and voxel-wise tissue volume showed significantly similar results between standard and EPImix-derived T1-weighted scans. Brain-age estimates from both sequences were significantly correlated, although EPImix T1-weighted scans showed a systematic offset in predictions of chronological age. Supplementary analyses suggest that this is likely caused by the reduced field of view of EPImix scans, and the use of a brain-age model trained using conventional T1-weighted scans. However, this systematic error can be corrected using additional regression of T1-predicted brain-age onto EPImix-predicted brain-age. Finally, retest EPImix scans acquired for 10 participants demonstrated high test-retest reliability in all evaluated quantitative measurements. Quantitative analysis of EPImix scans has potential to reduce scanning time, increasing participant comfort and reducing cost, as well as to support automation of scanning, utilising active learning for faster and individually-tailored (neuro)imaging.
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Affiliation(s)
- Harriet Hobday
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - James H Cole
- Department of Computer Science, Centre for Medical Image Computing, University College London, London, UK.,Dementia Research Centre, Institute of Neurology, University College London, London, UK
| | - Ryan A Stanyard
- Department of Forensic and Developmental Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.,Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - Richard E Daws
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Vincent Giampietro
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Owen O'Daly
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Robert Leech
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - František Váša
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.
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11
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Af Burén S, Kits A, Lönn L, De Luca F, Sprenger T, Skare S, Falk Delgado A. A 78 Seconds Complete Brain MRI Examination in Ischemic Stroke: A Prospective Cohort Study. J Magn Reson Imaging 2022; 56:884-892. [PMID: 35170134 PMCID: PMC9544312 DOI: 10.1002/jmri.28107] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 02/01/2022] [Accepted: 02/02/2022] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Fast 78-second multicontrast echo-planar MRI (EPIMix) has shown good diagnostic performance for detecting infarctions at a comprehensive stroke center, but its diagnostic performance has not been evaluated in a prospective study at a primary stroke center. PURPOSE To prospectively determine whether EPIMix was noninferior in detecting ischemic lesions compared to routine clinical MRI. STUDY TYPE Prospective cohort study. POPULATION A total of 118 patients with acute MRI and symptoms of ischemic stroke. FIELD STRENGTH AND SEQUENCE A 3 T. EPIMix (echo-planar based: T1-FLAIR, T2-weighted, T2-FLAIR, T2*, DWI) and routine clinical MRI sequences (T1-weighted fast spin echo, T2-weighted PROPELLER, T2-weighted-FLAIR fast spin echo, T2* gradient echo echo-planar, and DWI spin echo echo-planar). ASSESSMENT Three radiologists, blinded for clinical information, assessed signs of ischemic lesions (DWI↑, ADC↓, and T2/T2-FLAIR↑) on EPIMix and routine clinical MRI, with disagreements solved in consensus with a fourth reader to establish the reference standard. STATISTICAL TESTS Diagnostic performance including sensitivity and specificity against the reference standard was evaluated. EPIMix sensitivity was tested for noninferiority compared to the reference standard using Nam's restricted maximum likelihood estimation (RMLE) Score. A P-value < 0.05 was considered statistically significant. RESULTS Of 118 patients (mean age 62 ± 16 years, 58% males), 25% (n = 30) had MRI signs of acute infarcts. EPIMix was noninferior with 97% (95% CI 83-100) sensitivity for reader 1, 100% (95% CI 88-100) sensitivity for reader 2, and 90% (95% CI 88-98) sensitivity for reader 3 vs. 93% (95% CI 78-99) sensitivity for readers 1 and 2 and 90% (95% CI 74-98) for reader 3 on routine clinical MRI. Specificity was 99% (95% CI 94-100) for reader 1, 100% (95% CI 96-100) for reader 2, and 98% (95% CI 92-100) for reader 3 on EPIMix vs. 100% (95% CI 96-100) for all readers on routine clinical MRI. CONCLUSION EPIMix was noninferior to routine clinical MRI for the diagnosis of acute ischemic stroke. EVIDENCE LEVEL 2 TECHNICAL EFFICACY: Stage 2.
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Affiliation(s)
- Siri Af Burén
- Department of Radiology, Capio Saint Göran Hospital, Stockholm, Sweden.,Department of Clinical Science, Intervention and Technology, Karolinska Institute, Stockholm, Sweden
| | - Annika Kits
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden.,Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Lucas Lönn
- Department of Radiology, Capio Saint Göran Hospital, Stockholm, Sweden
| | - Francesca De Luca
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden.,Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Tim Sprenger
- Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden.,MR Applied Science Laboratory Europe, GE Healthcare, Stockholm, Sweden
| | - Stefan Skare
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden.,Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Anna Falk Delgado
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden.,Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
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12
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Demir S, Clifford B, Lo WC, Tabari A, Goncalves Filho ALM, Lang M, Cauley SF, Setsompop K, Bilgic B, Lev MH, Schaefer PW, Rapalino O, Huang SY, Hilbert T, Feiweier T, Conklin J. Optimization of magnetization transfer contrast for EPI FLAIR brain imaging. Magn Reson Med 2022; 87:2380-2387. [PMID: 34985151 PMCID: PMC8847235 DOI: 10.1002/mrm.29141] [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: 08/27/2021] [Revised: 12/10/2021] [Accepted: 12/11/2021] [Indexed: 11/06/2022]
Abstract
PURPOSE To evaluate the impact of magnetization transfer (MT) on brain tissue contrast in turbo-spin-echo (TSE) and EPI fluid-attenuated inversion recovery (FLAIR) images, and to optimize an MT-prepared EPI FLAIR pulse sequence to match the tissue contrast of a clinical reference TSE FLAIR protocol. METHODS Five healthy volunteers underwent 3T brain MRI, including single slice TSE FLAIR, multi-slice TSE FLAIR, EPI FLAIR without MT-preparation, and MT-prepared EPI FLAIR with variations of the MT-preparation parameters, including number of preparation pulses, pulse amplitude, and resonance offset. Automated co-registration and gray matter (GM) versus white matter (WM) segmentation was performed using a T1-MPRAGE acquisition, and the GM versus WM signal intensity ratio (contrast ratio) was calculated for each FLAIR acquisition. RESULTS Without MT preparation, EPI FLAIR showed poor tissue contrast (contrast ratio = 0.98), as did single slice TSE FLAIR. Multi-slice TSE FLAIR provided high tissue contrast (contrast ratio = 1.14). MT-prepared EPI FLAIR closely approximated the contrast of the multi-slice TSE FLAIR images for two combinations of the MT-preparation parameters (contrast ratio = 1.14). Optimized MT-prepared EPI FLAIR provided a 50% reduction in scan time compared to the reference TSE FLAIR acquisition. CONCLUSION Optimized MT-prepared EPI FLAIR provides comparable brain tissue contrast to the multi-slice TSE FLAIR images used in clinical practice.
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Affiliation(s)
- Serdest Demir
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Bryan Clifford
- Siemens Medical Solutions USA, Boston, Massachusetts, USA
| | - Wei-Ching Lo
- Siemens Medical Solutions USA, Boston, Massachusetts, USA
| | - Azadeh Tabari
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | | | - Min Lang
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Stephen F Cauley
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA.,Athinoula A. Martinos Center for Biomedical Imaging, Boston, Massachusetts, USA
| | - Kawin Setsompop
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Berkin Bilgic
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Michael H Lev
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Pamela W Schaefer
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Otto Rapalino
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Susie Y Huang
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA.,Athinoula A. Martinos Center for Biomedical Imaging, Boston, Massachusetts, USA
| | | | | | - John Conklin
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA.,Athinoula A. Martinos Center for Biomedical Imaging, Boston, Massachusetts, USA
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13
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Polak D, Splitthoff DN, Clifford B, Lo WC, Huang SY, Conklin J, Wald LL, Setsompop K, Cauley S. Scout accelerated motion estimation and reduction (SAMER). Magn Reson Med 2022; 87:163-178. [PMID: 34390505 PMCID: PMC8616778 DOI: 10.1002/mrm.28971] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 06/29/2021] [Accepted: 07/26/2021] [Indexed: 01/03/2023]
Abstract
PURPOSE To demonstrate a navigator/tracking-free retrospective motion estimation technique that facilitates clinically acceptable reconstruction time. METHODS Scout accelerated motion estimation and reduction (SAMER) uses a single 3-5 s, low-resolution scout scan and a novel sequence reordering to independently determine motion states by minimizing the data-consistency error in a SENSE plus motion forward model. This eliminates time-consuming alternating optimization as no updates to the imaging volume are required during the motion estimation. The SAMER approach was assessed quantitatively through extensive simulation and was evaluated in vivo across multiple motion scenarios and clinical imaging contrasts. Finally, SAMER was synergistically combined with advanced encoding (Wave-CAIPI) to facilitate rapid motion-free imaging. RESULTS The highly accelerated scout provided sufficient information to achieve accurate motion trajectory estimation (accuracy ~0.2 mm or degrees). The novel sequence reordering improved the stability of the motion parameter estimation and image reconstruction while preserving the clinical imaging contrast. Clinically acceptable computation times for the motion estimation (~4 s/shot) are demonstrated through a fully separable (non-alternating) motion search across the shots. Substantial artifact reduction was demonstrated in vivo as well as corresponding improvement in the quantitative error metric. Finally, the extension of SAMER to Wave-encoding enabled rapid high-quality imaging at up to R = 9-fold acceleration. CONCLUSION SAMER significantly improved the computational scalability for retrospective motion estimation and correction.
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Affiliation(s)
- Daniel Polak
- Department of Radiology, A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, USA.,Siemens Healthcare GmbH, Erlangen, Germany
| | | | | | | | - Susie Y. Huang
- Department of Radiology, A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, USA.,Harvard Medical School, Boston, Massachusetts, USA.,Harvard-MIT Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - John Conklin
- Department of Radiology, A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, USA.,Harvard Medical School, Boston, Massachusetts, USA
| | - Lawrence L. Wald
- Department of Radiology, A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, USA.,Harvard Medical School, Boston, Massachusetts, USA.,Harvard-MIT Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Kawin Setsompop
- Department of Radiology, Stanford School of Medicine, Stanford, California, USA
| | - Stephen Cauley
- Department of Radiology, A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, USA.,Harvard Medical School, Boston, Massachusetts, USA
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14
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Clifford B, Conklin J, Huang SY, Feiweier T, Hosseini Z, Goncalves Filho ALM, Tabari A, Demir S, Lo WC, Longo MGF, Lev M, Schaefer P, Rapalino O, Setsompop K, Bilgic B, Cauley S. An artificial intelligence-accelerated 2-minute multi-shot echo planar imaging protocol for comprehensive high-quality clinical brain imaging. Magn Reson Med 2021; 87:2453-2463. [PMID: 34971463 DOI: 10.1002/mrm.29117] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 10/29/2021] [Accepted: 11/22/2021] [Indexed: 02/06/2023]
Abstract
PURPOSE We introduce and validate an artificial intelligence (AI)-accelerated multi-shot echo-planar imaging (msEPI)-based method that provides T1w, T2w, T 2 ∗ , T2-FLAIR, and DWI images with high SNR, high tissue contrast, low specific absorption rates (SAR), and minimal distortion in 2 minutes. METHODS The rapid imaging technique combines a novel machine learning (ML) scheme to limit g-factor noise amplification and improve SNR, a magnetization transfer preparation module to provide clinically desirable contrast, and high per-shot EPI undersampling factors to reduce distortion. The ML training and image reconstruction incorporates a tunable parameter for controlling the level of denoising/smoothness. The performance of the reconstruction method is evaluated across various acceleration factors, contrasts, and SNR conditions. The 2-minute protocol is directly compared to a 10-minute clinical reference protocol through deployment in a clinical setting, where five representative cases with pathology are examined. RESULTS Optimization of custom msEPI sequences and protocols was performed to balance acquisition efficiency and image quality compared to the five-fold longer clinical reference. Training data from 16 healthy subjects across multiple contrasts and orientations were used to produce ML networks at various acceleration levels. The flexibility of the ML reconstruction was demonstrated across SNR levels, and an optimized regularization was determined through radiological review. Network generalization toward novel pathology, unobserved during training, was illustrated in five clinical case studies with clinical reference images provided for comparison. CONCLUSION The rapid 2-minute msEPI-based protocol with tunable ML reconstruction allows for advantageous trade-offs between acquisition speed, SNR, and tissue contrast when compared to the five-fold slower standard clinical reference exam.
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Affiliation(s)
- Bryan Clifford
- Siemens Medical Solutions USA, Boston, Massachusetts, USA
| | - John Conklin
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Susie Y Huang
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | | | | | | | - Azadeh Tabari
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Serdest Demir
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Wei-Ching Lo
- Siemens Medical Solutions USA, Boston, Massachusetts, USA
| | | | - Michael Lev
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Pam Schaefer
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Otto Rapalino
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Kawin Setsompop
- Department of Radiology and Department of Electrical Engineering, Stanford University, Stanford, California, USA
| | - Berkin Bilgic
- Department of Radiology, A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Stephen Cauley
- Department of Radiology, A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
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15
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Váša F, Hobday H, Stanyard RA, Daws RE, Giampietro V, O'Daly O, Lythgoe DJ, Seidlitz J, Skare S, Williams SCR, Marquand AF, Leech R, Cole JH. Rapid processing and quantitative evaluation of structural brain scans for adaptive multimodal imaging. Hum Brain Mapp 2021; 43:1749-1765. [PMID: 34953014 PMCID: PMC8886661 DOI: 10.1002/hbm.25755] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 11/02/2021] [Accepted: 11/21/2021] [Indexed: 12/17/2022] Open
Abstract
Current neuroimaging acquisition and processing approaches tend to be optimised for quality rather than speed. However, rapid acquisition and processing of neuroimaging data can lead to novel neuroimaging paradigms, such as adaptive acquisition, where rapidly processed data is used to inform subsequent image acquisition steps. Here we first evaluate the impact of several processing steps on the processing time and quality of registration of manually labelled T1 -weighted MRI scans. Subsequently, we apply the selected rapid processing pipeline both to rapidly acquired multicontrast EPImix scans of 95 participants (which include T1 -FLAIR, T2 , T2 *, T2 -FLAIR, DWI and ADC contrasts, acquired in ~1 min), as well as to slower, more standard single-contrast T1 -weighted scans of a subset of 66 participants. We quantify the correspondence between EPImix T1 -FLAIR and single-contrast T1 -weighted scans, using correlations between voxels and regions of interest across participants, measures of within- and between-participant identifiability as well as regional structural covariance networks. Furthermore, we explore the use of EPImix for the rapid construction of morphometric similarity networks. Finally, we quantify the reliability of EPImix-derived data using test-retest scans of 10 participants. Our results demonstrate that quantitative information can be derived from a neuroimaging scan acquired and processed within minutes, which could further be used to implement adaptive multimodal imaging and tailor neuroimaging examinations to individual patients.
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Affiliation(s)
- František Váša
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Harriet Hobday
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Ryan A Stanyard
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK.,Department of Forensic & Developmental Sciences, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Richard E Daws
- The Computational, Cognitive and Clinical Neuroimaging Laboratory, Department of Brain Sciences, Imperial College London, London, UK
| | - Vincent Giampietro
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Owen O'Daly
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - David J Lythgoe
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Jakob Seidlitz
- Department of Child and Adolescent Psychiatry and Behavioral Science, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.,Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Stefan Skare
- Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden.,Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Steven C R Williams
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Andre F Marquand
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK.,Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen, Nijmegen, The Netherlands.,Department for Cognitive Neuroscience, Radboud University Medical Center Nijmegen, Nijmegen, The Netherlands
| | - Robert Leech
- Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - James H Cole
- Department of Computer Science, Centre for Medical Image Computing, University College London, London, UK.,Dementia Research Centre, Institute of Neurology, University College London, London, UK
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16
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Sprenger T, Kits A, Norbeck O, van Niekerk A, Berglund J, Rydén H, Avventi E, Skare S. NeuroMix-A single-scan brain exam. Magn Reson Med 2021; 87:2178-2193. [PMID: 34904751 DOI: 10.1002/mrm.29120] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 11/23/2021] [Accepted: 11/24/2021] [Indexed: 01/15/2023]
Abstract
PURPOSE Implement a fast, motion-robust pulse sequence that acquires T1 -weighted, T2 -weighted, T2 * -weighted, T2 fluid-attenuated inversion recovery, and DWI data in one run with only one prescription and one prescan. METHODS A software framework was developed that configures and runs several sequences in one main sequence. Based on that framework, the NeuroMix sequence was implemented, containing motion robust single-shot sequences using EPI and fast spin echo (FSE) readouts (without EPI distortions). Optional multi-shot sequences that provide better contrast, higher resolution, or isotropic resolution could also be run within the NeuroMix sequence. An optimized acquisition order was implemented that minimizes times where no data is acquired. RESULTS NeuroMix is customizable and takes between 1:20 and 4 min for a full brain scan. A comparison with the predecessor EPIMix revealed significant improvements for T2 -weighted and T2 fluid-attenuated inversion recovery, while taking only 8 s longer for a similar configuration. The optional contrasts were less motion robust but offered a significant increase in quality, detail, and contrast. Initial clinical scans on 1 pediatric and 1 adult patient showed encouraging image quality. CONCLUSION The single-shot FSE readouts for T2 -weighted and T2 fluid-attenuated inversion recovery and the optional multishot FSE and 3D-EPI contrasts significantly increased diagnostic value compared with EPIMix, allowing NeuroMix to be considered as a standalone brain MRI application.
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Affiliation(s)
- Tim Sprenger
- MR Applied Science Laboratory Europe, GE Healthcare, Stockholm, Sweden.,Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Annika Kits
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Ola Norbeck
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Adam van Niekerk
- Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Johan Berglund
- Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Henric Rydén
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Enrico Avventi
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Stefan Skare
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
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17
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Ji S, Jeong J, Oh SH, Nam Y, Choi SH, Shin HG, Shin D, Jung W, Lee J. Quad-Contrast Imaging: Simultaneous Acquisition of Four Contrast-Weighted Images (PD-Weighted, T₂-Weighted, PD-FLAIR and T₂-FLAIR Images) With Synthetic T₁-Weighted Image, T₁- and T₂-Maps. IEEE TRANSACTIONS ON MEDICAL IMAGING 2021; 40:3617-3626. [PMID: 34191724 DOI: 10.1109/tmi.2021.3093617] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Magnetic resonance imaging (MRI) can provide multiple contrast-weighted images using different pulse sequences and protocols. However, a long acquisition time of the images is a major challenge. To address this limitation, a new pulse sequence referred to as quad-contrast imaging is presented. The quad-contrast sequence enables the simultaneous acquisition of four contrast-weighted images (proton density (PD)-weighted, T2-weighted, PD-fluid attenuated inversion recovery (FLAIR), and T2-FLAIR), and the synthesis of T1-weighted images and T1- and T2-maps in a single scan. The scan time is less than 6 min and is further reduced to 2 min 50 s using a deep learning-based parallel imaging reconstruction. The natively acquired quad contrasts demonstrate high quality images, comparable to those from the conventional scans. The deep learning-based reconstruction successfully reconstructed highly accelerated data (acceleration factor 6), reporting smaller normalized root mean squared errors (NRMSEs) and higher structural similarities (SSIMs) than those from conventional generalized autocalibrating partially parallel acquisitions (GRAPPA)-reconstruction (mean NRMSE of 4.36% vs. 10.54% and mean SSIM of 0.990 vs. 0.953). In particular, the FLAIR contrast is natively acquired and does not suffer from lesion-like artifacts at the boundary of tissue and cerebrospinal fluid, differentiating the proposed method from synthetic imaging methods. The quad-contrast imaging method may have the potentials to be used in a clinical routine as a rapid diagnostic tool.
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18
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Kits A, De Luca F, Kolloch J, Müller S, Mazya MV, Skare S, Falk Delgado A. One-Minute Multi-contrast Echo Planar Brain MRI in Ischemic Stroke: A Retrospective Observational Study of Diagnostic Performance. J Magn Reson Imaging 2021; 54:1088-1095. [PMID: 33942426 DOI: 10.1002/jmri.27641] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 03/27/2021] [Accepted: 03/31/2021] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Fast multi-contrast echo planar MRI (EPIMix) has comparable diagnostic performance to standard MRI for detecting brain pathology but its performance in detecting acute cerebral infarctions has not been determined. PURPOSE To assess the diagnostic performance of EPIMix for the detection of acute cerebral infarctions. STUDY TYPE Retrospective observational cohort. POPULATION One hundred and seventy-two consecutive patients with a clinical suspicion of non-hyperacute ischemic stroke (January 2018 to December 2019). FIELD STRENGTH AND SEQUENCE 1.5 T or 3 T. EPIMix ((echo-planar based: diffusion weighted (DWI), T2*-weighted, T2-weighted, T2- and T1-fluid attenuated inversion recovery (FLAIR) images) vs. standard MRI: echo-planar DWI, echo-planar T2*-weighted or susceptibility weighted, turbo spin-echo T2-weighted, T2- and T1-FLAIR turbo spin-echo sequences. ASSESSMENT Three neuroradiologists rated EPIMix and standard MRI on two separate occasions. Incongruent assessments were resolved in consensus with the fourth reader. The ratings included the diagnostic category (acute infarct, normal, and other pathology). Congruent diagnoses together with consensus diagnoses served as the reference standard. STATISTICAL TESTS The diagnostic performance of EPIMix and standard MRI against the reference standard was calculated by the area under the receiver operating characteristic curve (AUC) and compared by DeLong's test. Sensitivity and specificity were determined. Inter-rater agreements were evaluated by Fleiss's kappa. RESULTS Of 172 patients (61 ± 16 years, 103 men), acute infarcts were present in 80/172 (47%), normal findings in 60/172 (35%), and other pathology in 32/172 (19%). Across readers, the AUCs were .94-.95 for EPIMix and .95-.99 for standard MRI, with overlapping 95% CI (P = .02-.18). Inter-rater agreement for EPIMix was 0.90 and for standard MRI was 0.93. The sensitivity for EPIMix and standard MRI was 88-91% and 91-98%, respectively, while the specificity was 98-100% and 98-99%, both with overlapping 95% CI. CONCLUSION Multi-contrast echo planar MRI showed a high but marginally lower diagnostic performance compared to standard MRI for the detection and characterization of acute brain infarct. LEVEL OF EVIDENCE 3 TECHNICAL EFFICACY: Stage 2.
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Affiliation(s)
- Annika Kits
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Francesca De Luca
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Jens Kolloch
- Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Susanne Müller
- Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Michael V Mazya
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Neurology, Karolinska University Hospital, Stockholm, Sweden
| | - Stefan Skare
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Anna Falk Delgado
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
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19
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One-Minute Ultrafast Brain MRI With Full Basic Sequences: Can It Be a Promising Way Forward for Pediatric Neuroimaging? AJR Am J Roentgenol 2020; 215:198-205. [PMID: 32255685 DOI: 10.2214/ajr.19.22378] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE. The long scan time of brain MRI is a major drawback that limits its clinical use for evaluating pediatric patients who are inherently prone to motion and frequently require sedatives. This study investigated the clinical feasibility of a 1-minute ultrafast brain MRI protocol in pediatric patients by assessing its image quality in comparison with that of routine brain MRI. MATERIALS AND METHODS. Twenty-three patients were enrolled who underwent 1-minute ultrafast MRI and routine brain MRI protocols including five essential sequences (T1-weighted imaging, T2-weighted imaging, DWI, FLAIR, and T2*-weighted imaging). Total scan time for the same image contrast levels was 1 minute 11 seconds for ultrafast MRI versus 9 minutes 51 seconds for routine brain MRI. Two readers independently reviewed all images from the two MRI protocols and graded the image quality on a 4-point Likert scale. The Wilcoxon signed rank test was used to compare the readers' ratings; interobserver agreement between the readers was also assessed. RESULTS. Although the mean scores of overall image quality and anatomic delineation in ultrafast brain MR images were significantly lower than those in routine brain MR images, ultrafast brain MRI showed sufficient overall image quality and anatomic delineation with more than 2 points on the 4-point scale. CONCLUSION. The 1-minute ultrafast brain MRI protocol showed at least sufficient image quality compared with routine brain MRI. Therefore, 1-minute ultrafast brain MRI can be a viable first-line neuroimaging study for pediatric patients because of its shorter scan time, absence of radiation hazard, and reduced sedation requirements.
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20
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Norbeck O, Sprenger T, Avventi E, Rydén H, Kits A, Berglund J, Skare S. Optimizing 3D EPI for rapid T
1
‐weighted imaging. Magn Reson Med 2020; 84:1441-1455. [DOI: 10.1002/mrm.28222] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 01/14/2020] [Accepted: 01/29/2020] [Indexed: 01/17/2023]
Affiliation(s)
- Ola Norbeck
- Department of Neuroradiology Karolinska University Hospital Stockholm Sweden
- Department of Clinical Neuroscience Karolinska Institutet Stockholm Sweden
| | - Tim Sprenger
- MR Applied Science Laboratory Europe, GE Healthcare Stockholm Sweden
| | - Enrico Avventi
- Department of Neuroradiology Karolinska University Hospital Stockholm Sweden
- Department of Clinical Neuroscience Karolinska Institutet Stockholm Sweden
| | - Henric Rydén
- Department of Neuroradiology Karolinska University Hospital Stockholm Sweden
- Department of Clinical Neuroscience Karolinska Institutet Stockholm Sweden
| | - Annika Kits
- Department of Neuroradiology Karolinska University Hospital Stockholm Sweden
- Department of Clinical Neuroscience Karolinska Institutet Stockholm Sweden
| | - Johan Berglund
- Department of Clinical Neuroscience Karolinska Institutet Stockholm Sweden
| | - Stefan Skare
- Department of Neuroradiology Karolinska University Hospital Stockholm Sweden
- Department of Clinical Neuroscience Karolinska Institutet Stockholm Sweden
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21
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Ryu KH, Baek HJ, Skare S, Moon JI, Choi BH, Park SE, Ha JY, Kim TB, Hwang MJ, Sprenger T. Clinical Experience of 1-Minute Brain MRI Using a Multicontrast EPI Sequence in a Different Scan Environment. AJNR Am J Neuroradiol 2020; 41:424-429. [PMID: 32029473 DOI: 10.3174/ajnr.a6427] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 01/02/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND AND PURPOSE The long scan time of MR imaging is a major drawback limiting its clinical use in neuroimaging; therefore, we aimed to investigate the clinical feasibility of a 1-minute full-brain MR imaging using a multicontrast EPI sequence on a different MR imaging scanner than the ones previously reported. MATERIALS AND METHODS We retrospectively reviewed the records of 146 patients who underwent a multicontrast EPI sequence, including T1-FLAIR, T2-FLAIR, T2WI, DWI, and T2*WI sequences. Two attending neuroradiologists assessed the image quality of each sequence to compare the multicontrast EPI sequence with routine MR imaging protocols. We used the Wilcoxon signed rank test and McNemar test to compare the 2 MR imaging protocols. RESULTS The multicontrast EPI sequence generally showed sufficient image quality of >2 points using a 4-point assessment scale. Regarding image quality and susceptibility artifacts, there was no significant difference between the multicontrast EPI sequence DWI and routine DWI (P > .05), attesting to noninferiority of the multicontrast EPI, whereas there were significant differences in the other 4 sequences between the 2 MR imaging protocols. CONCLUSIONS The multicontrast EPI sequence showed sufficient image quality for clinical use with a shorter scan time; however, it was limited by inferior image quality and frequent susceptibility artifacts compared with routine brain MR imaging. Therefore, the multicontrast EPI sequence cannot completely replace the routine MR imaging protocol at present; however, it may be a feasible option in specific clinical situations such as screening, time-critical diseases or for use with patients prone to motion.
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Affiliation(s)
- K H Ryu
- From the Department of Radiology (K.H.R., H.J.B., J.I.M., B.H.C., S.E.P., J.Y.H., T.B.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon, Republic of Korea
| | - H J Baek
- From the Department of Radiology (K.H.R., H.J.B., J.I.M., B.H.C., S.E.P., J.Y.H., T.B.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon, Republic of Korea .,Department of Radiology (H.J.B.), Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, Republic of Korea
| | - S Skare
- Department of Clinical Neuroscience (S.S., T.S.), Karolinska Institute, Stockholm, Sweden.,Department of Neuroradiology (S.S.), Karolinska University Hospital, Stockholm, Sweden
| | - J I Moon
- From the Department of Radiology (K.H.R., H.J.B., J.I.M., B.H.C., S.E.P., J.Y.H., T.B.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon, Republic of Korea
| | - B H Choi
- From the Department of Radiology (K.H.R., H.J.B., J.I.M., B.H.C., S.E.P., J.Y.H., T.B.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon, Republic of Korea
| | - S E Park
- From the Department of Radiology (K.H.R., H.J.B., J.I.M., B.H.C., S.E.P., J.Y.H., T.B.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon, Republic of Korea
| | - J Y Ha
- From the Department of Radiology (K.H.R., H.J.B., J.I.M., B.H.C., S.E.P., J.Y.H., T.B.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon, Republic of Korea
| | - T B Kim
- From the Department of Radiology (K.H.R., H.J.B., J.I.M., B.H.C., S.E.P., J.Y.H., T.B.K.), Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon, Republic of Korea
| | - M J Hwang
- MR Applications and Workflow, GE Healthcare (M.J.H.), Seoul, Republic of Korea
| | - T Sprenger
- Department of Clinical Neuroscience (S.S., T.S.), Karolinska Institute, Stockholm, Sweden.,MR Applied Science Laboratory Europe (T.S.), GE Healthcare Stockholm, Sweden
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22
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van Zijl P, Knutsson L. In vivo magnetic resonance imaging and spectroscopy. Technological advances and opportunities for applications continue to abound. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 306:55-65. [PMID: 31377150 PMCID: PMC6703925 DOI: 10.1016/j.jmr.2019.07.034] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 06/19/2019] [Accepted: 07/08/2019] [Indexed: 05/07/2023]
Abstract
Over the past decades, the field of in vivo magnetic resonance (MR) has built up an impressive repertoire of data acquisition and analysis technologies for anatomical, functional, physiological, and molecular imaging, the description of which requires many book volumes. As such it is impossible for a few authors to have an authoritative overview of the field and for a brief article to be inclusive. We will therefore focus mainly on data acquisition and attempt to give some insight into the principles underlying current advanced methods in the field and the potential for further innovation. In our view, the foreseeable future is expected to show continued rapid progress, for instance in imaging of microscopic tissue properties in vivo, assessment of functional and anatomical connectivity, higher resolution physiologic and metabolic imaging, and even imaging of receptor binding. In addition, acquisition speed and information content will continue to increase due to the continuous development of approaches for parallel imaging (including simultaneous multi-slice imaging), compressed sensing, and MRI fingerprinting. Finally, artificial intelligence approaches are becoming more realistic and will have a tremendous effect on both acquisition and analysis strategies. Together, these developments will continue to provide opportunity for scientific discovery and, in combination with large data sets from other fields such as genomics, allow the ultimate realization of precision medicine in the clinic.
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Affiliation(s)
- Peter van Zijl
- Department of Radiology, Johns Hopkins University, F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA.
| | - Linda Knutsson
- Department of Medical Radiation Physics, Lund University, Lund, Sweden
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