MRI of the Chest Under High Frequency Ventilation

Study Overview
=================
Brief Summary
-----------------
The purpose of the study is to evaluate the benefit on image quality of MRI of the chest performed under high frequency non-invasive ventilation. This technique indeed allows to generate an apnea duration of several minutes with acquisitions performed at full inspiration. This study will be applied on healthy subjects.

Detailed Description
-----------------
High frequency ventilation (HF-V) has been applied by using a non-invasive interface allowing to obtain a prolonged apnea in awaken subjects. Such an application should be of interest for MRI taking into account its susceptibility to motion of the chest and the imperfect techniques of respiratory gating that are usually performed at end expiration. The purpose of this study is to assess the benefit on image quality of different sequences performed with and without the device in healthy subjects.

Official Title
-----------------
MRI of the Chest Under High Frequency Ventilation

Conditions
-----------------
Non-invasive Ventilation, High-frequency Ventilation, Healthy Volunteer

Intervention / Treatment
-----------------
* Device: MRI with High-frequency non-invasive ventilation
* Other: MRI without High-frequency non-invasive ventilation


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Healthy subjets : normal respiratory function and no known lung disease Age >=18y Exclusion Criteria: • Pregnancy

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Diagnostic
Allocation: Non-Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: MRI with HF-NIV<br>Intervention: Acquisition of MRI with High-Frequency non-invasive ventilation (HF-NIV) | Device: MRI with High-frequency non-invasive ventilation<br>* MRI performed under high-frequency non-invasive ventilation<br>|
| Active Comparator: MRI without HF-NIV<br>Intervention: MRI without High-Frequency non-invasive ventilation (HF-NIV) | Other: MRI without High-frequency non-invasive ventilation<br>* MRI performed without High-frequency non-invasive ventilation<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Image quality assessment (soapbubble, maximum of first derivative, signal to noise, contrast to noise) | Image quality and artefacts will be evaluated and compared without and with the device. Sharpness of the interfaces between vessels and lung will be evaluated with the Soapbubble software (Etienne et al., Magn Reson Med. 2002 Oct;48(4):658-66). The interface between diaphragm and lung will be evaluated with the maximum of the first derivative (Tibiletti et al., Magn Reson Med. 2016 Mar;75(3):1324-32). Signal to noise and contrast to noise will be measured within regions of interest in the image. | within 2 weeks after MRI acquisition | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Heart and coronary arteries evaluation (soapbubble, signal to noise, contrast to noise) | The potential benefit on the exploration of the heart and coronary arteries will be assessed. Sharpness of the coronary arteries with respect to the neighbouring tissue will be evaluated with the Soapbubble software (Etienne et al., Magn Reson Med. 2002 Oct;48(4):658-66). Signal to noise and contrast to noise will be measured within regions of interest in the image. | within 2 weeks after MRI acquisition | 
| Synchronization of the acquisition | The possibility of synchronizing the MRI acquisition with the ventilation system will be explored with the aim to eliminate residual diaphragmatic motion and evaluate the potential additional benefit in terms of image quality and artefacts will be evaluated. | during the MRI examination | 
| Subjective tolerance (questionnaire) | Subjective tolerance of MRI examination under HF-NIV (questionnaire). Participants will fill the questionnaire right after the examination end. | at the end of the MRI examination | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
MRI, Chest, Apnea