Low-Field MRI in Stroke Code Patients (LFMIS)

Validation of Low Field MRI in Patients With Stroke Symptoms Less Than 12 Hours

This study evaluates the accuracy and feasibility of a portable low-field MRI (Hyperfine) device in patients presenting to the emergency department with suspected acute stroke. All enrolled patients undergo standard clinical imaging (CT, CT angiography, CT perfusion) and additionally receive a low-field MRI scan. Low-field MRI findings are compared to routine CT imaging and final clinical diagnosis. The study aims to determine whether low-field MRI can reliably detect acute ischemic stroke (including lacunar and large vessel occlusion), hemorrhagic stroke, and stroke mimics in the acute setting. Secondary outcomes include feasibility measures such as scan time, completion rate, patient satisfaction, and adverse events.

Study Overview

• Status: Recruiting
• Conditions: Acute Stroke; MRI Imaging
• Intervention / Treatment: Device: Low-field MRI

• Study Type: Observational
• Enrollment (Estimated): 80

Contacts and Locations

• Study Contact: Name: Nyika Kruyt, MD, PhD; Phone Number: +31 71 526 9111; Email: n.d.kruyt@lumc.nl
• Study Contact Backup: Name: Robert Croese; Email: r.j.i.croese@lumc.nl

Study Locations

• Netherlands
  • South Holland
    • Leiden, South Holland, Netherlands, 2333ZA
      • Recruiting
      • Leiden University Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Adult patients presenting to the emergency department of a tertiary academic hospital (LUMC) with suspected acute stroke (stroke code activation) within 12 hours of symptom onset. The study population includes patients with ischemic stroke (large vessel occlusion and lacunar), hemorrhagic stroke, and stroke mimics, reflecting real-world acute stroke diagnostics.

Description

Inclusion Criteria:

• Age ≥ 18 years
• Presentation with suspected acute stroke (stroke code activation by ambulance paramedics)
• Symptom onset < 12 hours prior to presentation
• Admission to the emergency department of the Leiden University Medical Center (LUMC) during office hours
• Undergoing standard-of-care head CT imaging at the emergency department
• Ability to provide informed consent (written or verbal in the acute setting, with deferred written consent if applicable)

Exclusion Criteria:

• Imminent death
• Severe claustrophobia preventing MRI
• Presence of MRI-incompatible implanted devices (e.g., pacemaker, cochlear implant, insulin pump)
• Known intra-ocular metallic foreign body or intracranial metallic clip/device identified on admission CT
• Pregnancy
• Acute life-threatening or disabling condition requiring immediate intervention that precludes study procedures
• Any study-related delay that could interfere with time-critical stroke treatments (intravenous thrombolysis or endovascular thrombectomy)

Study Plan

How is the study designed?

Number of groups / cohorts

4

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Ischemic stroke - lacunar infarct; Patients with clinical and radiological suspicion of lacunar ischemic stroke (subcortical infarct). These patients often receive additional conventional MRI during routine work-up for radiological confirmation. All patients undergo low-field MRI scanning in addition to routine clinical imaging.	Device: Low-field MRI; All participants undergo a low-field MRI scan (Hyperfine Swoop, 0.064 Tesla) in addition to routine clinical imaging (CT, CT angiography, CT perfusion). The low-field MRI is performed after routine imaging and treatment decisions. This is an observational study evaluating the diagnostic accuracy and feasibility of low-field MRI in acute stroke patients.
Hemorrhagic stroke; Patients with hemorrhagic stroke (intracerebral hemorrhage) demonstrated on non-contrast CT at the emergency department. All patients undergo low-field MRI scanning in addition to routine clinical imaging.	Device: Low-field MRI; All participants undergo a low-field MRI scan (Hyperfine Swoop, 0.064 Tesla) in addition to routine clinical imaging (CT, CT angiography, CT perfusion). The low-field MRI is performed after routine imaging and treatment decisions. This is an observational study evaluating the diagnostic accuracy and feasibility of low-field MRI in acute stroke patients.
Stroke mimic; Patients with non-stroke diagnosis based on clinical judgment and neuro-imaging at the emergency department (e.g., epilepsy, migraine, functional neurological disorder). All patients undergo low-field MRI scanning in addition to routine clinical imaging.	Device: Low-field MRI; All participants undergo a low-field MRI scan (Hyperfine Swoop, 0.064 Tesla) in addition to routine clinical imaging (CT, CT angiography, CT perfusion). The low-field MRI is performed after routine imaging and treatment decisions. This is an observational study evaluating the diagnostic accuracy and feasibility of low-field MRI in acute stroke patients.
Ischemic stroke - proximal vessel occlusion; Patients with ischemic stroke due to proximal vessel occlusion in the anterior circulation (large vessel occlusion, LVO) diagnosed by CT angiography at the emergency department. All patients in this group undergo low-field MRI scanning in addition to routine clinical imaging.	Device: Low-field MRI; All participants undergo a low-field MRI scan (Hyperfine Swoop, 0.064 Tesla) in addition to routine clinical imaging (CT, CT angiography, CT perfusion). The low-field MRI is performed after routine imaging and treatment decisions. This is an observational study evaluating the diagnostic accuracy and feasibility of low-field MRI in acute stroke patients.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Diagnostic accuracy of low-field MRI for acute stroke detection	Sensitivity, specificity, positive predictive value, and negative predictive value of low-field MRI findings for detecting acute stroke (ischemic or hemorrhagic) and stroke mimics, using final clinical diagnosis at discharge as the reference standard. Low-field MRI images are assessed by a neuroradiologist blinded to CT findings and final diagnosis.	At time of low-field MRI scan (within 12 hours of symptom onset)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Adverse events during low-field MRI scanning	Number and type of adverse events (AEs) and serious adverse events (SAEs) occurring during the low-field MRI scanning procedure or within 30 minutes after completion.	During low-field MRI scan and up to 30 minutes thereafter
Patient satisfaction with low-field MRI procedure	Patient-reported satisfaction with the low-field MRI scanning experience, assessed using a structured questionnaire or verbal interview.	Within 24 hours after low-field MRI scan.

Collaborators and Investigators

• Sponsor: Leiden University Medical Center

Publications and helpful links

General Publications

• Mazurek MH, Cahn BA, Yuen MM, Prabhat AM, Chavva IR, Shah JT, Crawford AL, Welch EB, Rothberg J, Sacolick L, Poole M, Wira C, Matouk CC, Ward A, Timario N, Leasure A, Beekman R, Peng TJ, Witsch J, Antonios JP, Falcone GJ, Gobeske KT, Petersen N, Schindler J, Sansing L, Gilmore EJ, Hwang DY, Kim JA, Malhotra A, Sze G, Rosen MS, Kimberly WT, Sheth KN. Portable, bedside, low-field magnetic resonance imaging for evaluation of intracerebral hemorrhage. Nat Commun. 2021 Aug 25;12(1):5119. doi: 10.1038/s41467-021-25441-6.
• Sheth KN, Mazurek MH, Yuen MM, Cahn BA, Shah JT, Ward A, Kim JA, Gilmore EJ, Falcone GJ, Petersen N, Gobeske KT, Kaddouh F, Hwang DY, Schindler J, Sansing L, Matouk C, Rothberg J, Sze G, Siner J, Rosen MS, Spudich S, Kimberly WT. Assessment of Brain Injury Using Portable, Low-Field Magnetic Resonance Imaging at the Bedside of Critically Ill Patients. JAMA Neurol. 2020 Sep 8;78(1):41-7. doi: 10.1001/jamaneurol.2020.3263. Online ahead of print.

Study record dates

Study Major Dates

• Study Start (Actual): April 20, 2026
• Primary Completion (Estimated): April 1, 2027
• Study Completion (Estimated): August 1, 2027

Study Registration Dates

• First Submitted: July 3, 2026
• First Submitted That Met QC Criteria: July 10, 2026
• First Posted (Actual): July 14, 2026

Study Record Updates

• Last Update Posted (Actual): July 14, 2026
• Last Update Submitted That Met QC Criteria: July 10, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: Acute stroke; Low-field MRI; Hyperfine
• Additional Relevant MeSH Terms: Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Stroke
• Other Study ID Numbers: NL87809.058.24

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Due to the limited sample size, the single-centre design, and privacy considerations under GDPR, there is no plan to share individual participant data. Aggregate results will be published in peer-reviewed journals and presented at scientific meetings.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: Yes