MR Compatible Accelerometer for Respiratory MOTion Measurement

Study Overview
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Brief Summary
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A novel magnetic resonance (MR) compatible accelerometer for respiratory motion sensing (MARMOT) has been developed as a surrogate of the vendors' pneumatic belts. The aim is to model and correct respiratory motion for free-breathing thoracic-abdominal MR imaging and to simplify patient installation.

Detailed Description
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Respiratory motion is a serious problem in the acquisition of high-quality thoracic/abdominal magnetic resonance (MR) images. Various methods have been proposed to compensate the motion-induced artefacts, including breathholding, respiratory gating and model-driven motion correction. Breath-holding is the simplest among the three. However this conventional clinical method induces various problem, including inefficient use of scanners, inconsistent organ position between each breath-hold, imaging an altered physiological status and patient inconvenience especially for those who suffer from respiration difficulties. Free-breathing MR acquisition has therefore become of great clinical interest recently. The investigators intend to examine the efficacy of the MARMOT sensors for: modelling and predicting the respiratory motions in abdominal scans, correcting for the respiratory motion in a cardiac cine scan, via a reconstruction-based method.

Official Title
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MR Compatible Accelerometer for Respiratory MOTion Measurement

Conditions
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Heart Disease

Intervention / Treatment
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* Device: MRI compatible motion sensor (MARMOT)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: To not have cardiac, hepatic or renal pathology To be more than 18 To be enrolled in a social security plan To have signed an informed consent To have preliminary medical examination Exclusion Criteria: Contraindication: implantable devices (pacemakers, defibrillators, cochlear implants, etc.), metallic foreign bodies Impossibility to undergo MRI : claustrophobia, morbid obesity Pregnancy or risk of pregnancy Patient under a measure of legal protection

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Healthy volunteers<br>Volunteers without cardiac, hepatic or renal pathology | Device: MRI compatible motion sensor (MARMOT)<br>* MRI with motion control (several motion sensors placed on the volunteer's body)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Respiratory movement using respiratory belts | Respiratory belts, which are usually used in MRI to monitor respiratory movements and brath-holding, are placed around the volunteer's body (on the abdominal and on the thoracic level). They give the average displacement (in mm) across time generated by the respiratory movement. | four months | 
| Respiratory movement using MARMOT sensors | MARMOT sensors are placed on the volunteer's body (4 sensors placed on the thorax or on the abdomen). MARMOT sensors give 2 measures : acceleration generated by the respiratory movement (in mm/s²) in 3 directions and rotation generated by the respiratory movement (angle in °/s) in 3 directions. | four months | 
| Respiratory movement using real-time MR images | Motion measurement (in mm) directly on the MR images (using real-time MR imaging) | four months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Subjective quality (marks between 1 (the best) and 3 (the worst) of the reconstructed MR images) | Comparing the quality of the reconstructed cardiac cine images obtained with the cine-GRICS algorithm using: the pneumatic belts alone all MARMOT signals signals from only one MARMOT sensor. Three cardiologists are shown with the motion-compensated cine movies obtained using these three sensor configurations. The movies are presented in random ordering on the screen so that the clinicians are blind to the sensor configuration. They are then asked to rank them by overall image quality (1=best, 2=second best, 3=worst). Equal quality ranking is allowed in this procedure. | four months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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MRI, Motion, Respiratory movement, Artifacts correction