co-Principal Investigator Sean Fain, Ph.D.
A group of 52 Childhood Origins of Asthma (COAST) children who either have a history of severe colds and/or abnormal breathing tests have been randomly chosen to participate in a sub-study that will include a Magnetic Resonance Imaging (MRI) scan at their 9 year COAST visit. The purpose of this study is to look at differences in lung structure and functioning among children with various histories of viral illness and breathing test scores.
We will use MRI (Magnetic Resonance Imaging) to look at how air fills your child's lungs. MRI uses a magnetic field rather than x-rays to take pictures of your child's body. During each visit your child will be asked to inhale an investigational gas to help us see his/her lungs. An investigational or experimental agent is an agent that is not yet approved by the Food and Drug Administration (FDA) for commercial or clinical use and is available for research only. This gas is called NC100182-Inhalation and it contains Helium-3, a rare, non-radioactive form of helium that is mixed with nitrogen. The inhaling of NC100182-Inhalation will help show how air fills different parts of your child's lungs and has been shown to be different for adults with asthma versus adults without.
For the MRI, your child will be placed in the center of a large metal doughnut-shaped magnet. The MRI machine produces a magnetic field, which passes through your child's body without disturbing any of its parts. The scan itself takes approximately one hour and the visit will last approximately four hours.
As part of the MRI substudy, you would complete multiple procedures. The following procedures will be done at each visit:
- Breathing games (pulmonary function testing)
- Heart rate and rhythm monitoring
- Pulse oximeter (a clip on the finger that reads blood oxygen level and heart rate)
- Magnetic resonance imaging (MRI) using an imaging coil (special vest worn during scan to help visualize the lungs) To see a video of this procedure, click here or scroll down to the bottom of the page.
- Blood pressure will be taken with a cuff worn on the arm during the scan
The MRI Scan:
Your child will change into a hospital gown prior to being placed in the center of the scanner (a large doughnut shaped magnet). A special vest referred to as a "coil" will be placed over their chest. Your child will be cushioned to keep them from becoming uncomfortable. During the time your child is having the scan, he/she will have a blood pressure cuff on one of their arms that will measure their blood pressure, a small clip on one of their fingers that will monitor their heart rate and oxygen level, as well as small pads on their chest attached to wires that will be used to measure their heart activity (ECG).
During the imaging session, your child will be closely monitored for any signs of distress with the blood pressure, heart monitor and oxygen monitor mentioned before. They will be able to stop the test at any time. If it is necessary for your child's comfort and safety, you may be able to stay in the room during the scans and your child may be able to come out of the scanner between scans. In order to remain in the room during the scan you will have a safety screening.
During the imaging study, your child will lie on a small bed that can be moved into and out of the scanner. After the bed has been moved into the scanner, your child will be asked to inhale the investigational gas through a straw. They will then be asked to hold their breath for 10-12 seconds while a scan is done. Your child will be asked to repeat this procedure of inhaling the gas and holding their breath 2-3 times. When the imaging is completed, your child will be removed from the scanner, and the blood pressure, heart rate and oxygen monitor will be checked again. The picture at right shows an image of lungs seen during the scan.
You and your child will be asked to remain at the center for one hour after imaging for observation. During this time a snack will be provided, breathing games will be repeated and your child's vital signs will be taken to be sure there have been no side effects from the scan.
Click here to view a video of a scan of a child breathing the NC100182-Inhalation. (link to follow)
RISKS: Although no known ill effects have been directly linked to exposure to radio waves or the strong magnetic field used in MRI, it is not safe to scan people with certain types of metal in their bodies (pacemakers, body piercings, etc). It is important to answer the screening questions prior to the scan as accurately as possible. During some fast MRI scans, people have occasionally reported "tingling" or "twitching" sensations in their arms or legs, especially when their hands were clasped. Therefore, your child will be asked to lie with his/her hands unclasped and to report any unusual feelings they experience.
Sometimes patients experience a feeling of claustrophobia (fear of enclosed spaces) during the MRI scan. A microphone is built into the machine so that a technician will be able to hear your child if he/she needs help.
The ECG leads cause no risk or discomfort, but may cause minor skin irritation or reddening when removed. During a scan, the scanner makes a loud tapping or "chirping" noise. Your child will be given headphones to help cover up this sound and to communicate with the MRI operator.
The special vest (imaging coil) being used in this study has no known risks and meets FDA guidelines. However, the coil is considered investigational, because it is not yet FDA approved. There is a rare potential risk of a skin burn associated with the use of any MR imaging coils, including the coil being used in this study. The risk of burn is very small. In addition, the computer will check to make sure that the coil is working correctly before the scan starts.
NC100182-Inhalation Risks: This is the experimental helium gas that your child will breathe in during the MRI. It is an investigational agent that has not yet been approved by the FDA and therefore, the safety of the agent cannot be guaranteed. Side effects are not well known and therefore to minimize any potential risks, MR imaging will be performed during a very short breath hold of 10-12 seconds. During each brief, single-breath hold of the gas, the oxygen level in the blood could possibly go down temporarily, causing mild shortness of breath. There could also be a tickling sensation in your child's throat because the gas is dry. In addition, your child's voice could also increase in pitch for a short time following inhalation of helium. This is of no concern and will change quickly back to normal after breathing room air. There may be additional risks to your child, which are not known and unexpected including the possibility of long-term effects. Your child will be carefully watched for side effects during and after he/she has breathed in the gas and your child will be treated right away if needed. An oxygen mask and other emergency procedures are readily available to treat emergencies.
MRI Scan Video:
**To the left is a video of healthy lungs during an MRI scan.