This study capitalizes on the emerging technology of 19F MRI, using conventional 'thermally' polarized perfluorinated gas (perfluoropropane, or PFP) mixed with oxygen and studied with magnetic resonance imaging (MRI) to visualize ventilation. This technique has not been studied in children. Children and adolescents (6-17 years old) with cystic fibrosis (CF) who have normal spirometry will undergo 19F MRI with the inhalation of an inert contrast gas to study ventilation. Comparisons will be made to a cohort of healthy children (6-17 years old) who will perform the same measures. The primary outcome measure is the feasibility of conducting these studies in the pediatric population. Parallel performance of multiple breath nitrogen washout (MBW) and spirometry will be used to compare the sensitivity of these outcomes to the presence of mild lung disease in these children. Finally, the investigators will compare data obtained during standard breath holds with a novel "free-breathing" technique that will eliminate the need for breath holds during MRI acquisition.
Study Type
OBSERVATIONAL
Enrollment
15
Inhalation of a biologically inert contrast gas, perfluoropropane, combined with 19F-tuned MRI with image acquisition at breath-hold and during tidal breathing.
University of North Carolina at Chapel Hill
Chapel Hill, North Carolina, United States
RECRUITINGParticipation rate
The number of eligible participants approached for the study divided by the number who consent to participate.
Time frame: through study completion, recruitment for 2 years
Completion rate
The number of consented participants divided by the number of participants who complete each portion of the study.
Time frame: through study completion, recruitment for 2 years
Parental acceptability score
Acceptability questionnaire for guardian; 2 questions, each on a 10 point Likert scale * Implementation: qualitative description of barriers encountered * Practicality: % of participants completing the study with research quality data
Time frame: Day 1, assessed at single visit
Child acceptability score
Acceptability questionnaire for participant; 2 questions, each on a 10 point Likert scale * Implementation: qualitative description of barriers encountered * Practicality: % of participants completing the study with research quality data
Time frame: Day 1, assessed at single visit
MRI defined ventilation defect parameters (VDP) in healthy participants
The 19F Volumetric interpolated breath-hold examination (VIBE) scans and proton nuclear magnetic resonance imaging (1H-MRI) will be saved as Digital Imaging and Communications in Medicine (DICOM) images and imported to Medical Image Merge (MIM) software. The percentage of lung with ventilation defects (VDP) after the 5th inspiratory cycle will be measured, using the 95th percentile of background noise on the last wash-in scan as the threshold value defining absence of ventilation. The investigators will assess ventilation defect parameters (VDP) scored in healthy participants (mean + SD)
Time frame: Day 1, assessed at single visit
MRI defined fraction of lung volume with slow gas washout time (FLVlongtau2) in healthy participants
The 19F Volumetric interpolated breath-hold examination (VIBE) scans and 1H-MRI will be saved as Digital Imaging and Communications in Medicine (DICOM) images and imported to Medical Image Merge (MIM) software. The fraction of the total lung volume with slow gas wash-out kinetics (FLV↑tau2) will be calculated for lung regions without an overlapping full ventilation defect. The investigators will assess FLVlongtau2 scored in healthy participants (mean + SD)
Time frame: Day 1, assessed at single visit
MRI defined VDP in participants with cystic fibrosis
The 19F VIBE scans and 1H-MRI will be saved as Digital Imaging and Communications in Medicine (DICOM) images and imported to Medical Image Merge (MIM) software. The percentage of lung with ventilation defects (VDP) after the 5th inspiratory cycle will be measured, using the 95th percentile of background noise on the last wash-in scan as the threshold value defining absence of ventilation. The investigators will assess ventilation defect parameters (VDP) scored in participants with cystic fibrosis (mean + SD)
Time frame: Day 1, assessed at single visit
MRI defined fraction of lung volume with slow gas washout time (FLVlongtau2) in participants with cystic fibrosis
The 19F Volumetric interpolated breath-hold examination (VIBE) scans and 1H-MRI will be saved as Digital Imaging and Communications in Medicine (DICOM) images and imported to Medical Image Merge (MIM) software. The fraction of the total lung volume with slow gas wash-out kinetics (FLV↑tau2) will be calculated for lung regions without an overlapping full ventilation defect. The investigators will assess FLVlongtau2 scored in participants with cystic fibrosis (mean + SD)
Time frame: Day 1, assessed at single visit
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