The Use of a Mock MRI Scanner for Reducing the Use of Anesthesia in Children Undergoing Clinical MRI Scans

Diagnostic MR procedures can be scary and stressful for children and parents. Because patients must lie still during the procedure to provide diagnostic quality images, young children (typically <7 years) and others not expected to comply are often sedated or given general anesthesia (GA) for imaging procedures. However, the high cost of GA and its associated risks motivate the search for alternatives. Previous reports demonstrate that preparation (including using a mock MR scanner) reduces anxiety and increases compliance for clinical and research MRI procedures without GA. However, systematic studies of the advantages of a mock MR scanner versus other training methods are lacking. Furthermore, while reducing the use of GA is desirable, repeated unsuccessful scanning procedures are also costly, so identifying factors that predict success for diagnostic MR procedures is important to effectively allocate resources.

Aims

The overall goal of this study is to systematically investigate whether training on the mock MR scanner reduces the need for GA during MRI scans in children. There are three specific aims:

1. Determine whether pre-scan training allows children to have successful diagnostic MRI scans without general anesthesia.
2. Examine the effects of different types of pre-scan training on reducing anxiety and stress in children and their parents related to diagnostic MRI.
3. Determine whether mock scanner training can lower the age at which neuro-oncology patients are able to complete a full diagnostic MRI without anesthesia compared with historic controls.

Patient name, date of birth, and hospital identification number are necessary to perform chart review and access diagnostic images. All identifying information will be removed prior to data analysis.

The following data will be collected/recorded for each participant at enrollment:

1. Study number
2. Sex
3. Age at time of scan(s)
4. Type of diagnostic scans requested
5. Parent report on overall stress
6. Parent proxy measures of child stress/worry (PedsQL)
7. Parent predictions of child success on MRI
8. (Aim 3 only) Primary Oncology Diagnosis: i) Site ii) Histology
9. (Aim 3 only) Treatment mode i) Surgery ii) Chemotherapy iii) Radiotherapy

Training Sessions

For Aims 1 and 2, participants will be randomly assigned to one of three training groups. Group 1 will be sent links to online videos about MRI, audio files with scanner noises, and a children's book about MR scans, to prepare at home. Group 2 will receive training materials and visit the ACH to review them with the research team, but will not use the mock scanner. Group 3 will receive training materials and visit the ACH for training on the mock MR scanner. Visits to the mock scanner for Group 3 will include practice lying down, staying still, wearing headphones, and watching a movie on the mirror system. The Child Life Specialist will talk with the child and his/her family about the experience, and allow them up to 1 hour of practice time on the mock scanner.

For Aim 3, all participants will receive training on the mock scanner similar to group 3 with the difference being Child Life Specialists will utilize a goal based preparation of 3 X 20 minute sessions to coincide with other visits to the hospital.

All participants will be booked for one MR scan without GA and one with GA a week later in case the first scan fails.

The following data will be collected during/after training sessions:

1. Total time spent preparing (mock scanner or other)
2. Child's feelings of stress/worry before and after visit (PedsQL)
3. Head motion during mock MRI session (if applicable)

Diagnostic MRI Sessions

The following information will be recorded for each child's MRI scan:

1. Date of MRI.
2. Child's age at time of scanning.
3. Scan success without anesthesia (pass/fail)
4. Number of sequences requiring repeating
5. Total scan length (mins)
6. Sum of individual scan sequence times (mins)
7. Quality of images, as determined by a pediatric neuro-radiologist and graded as Excellent (no motion artifact ), Good (minimal motion artifact ); Acceptable (motion artifact; but satisfactory to answer the clinical question); Unacceptable (significant motion artifact ; unable to answer the clinical question)
8. Parent proxy measures of child stress ( PedsQL )
9. Child's stress/worry (PedsQL)
10. (Aims 1 and 2) Saliva sample to measure cortical and salivary alpha amylase before and after diagnostic MR scan

If images are deemed suitable for clinical diagnosis, the subsequent GA booking will be cancelled.

No raw images will be retained for any patients outside of their hospital record.

For Aim 3 prospective data, the above information will be recorded at each scanning session until the patient is able to complete the entire scan without anesthesia.

For Aim 3 retrospective data: The patient's hospital identification number will be used to identify MRI scans performed on that patient in the 3 years prior to the study. The MRI report will be cross referenced with the department of anesthesia electronic database to determine the date and thereby the age at which MRI without GA was able to be performed. In the case where the MRI report states that scan was performed under GA but no electronic record of GA is present the paper chart will be reviewed to determine if GA was performed. If The MRI scan report does not specify that GA was performed and an anesthesia record for the MRI exists then scan will be considered to have been performed under GA.

Statistical Plan

An ANOVA will be used to evaluate group differences on scanning success measures. Additional analyses will focus on correlations between scan successes and age, sex, measures of child/parent stress, cortisone, salivary alpha amylase, and training session compliance.

Aim 3 will also explicitly test differences in the mean age in months at which neuro-oncology patients were able to successfully complete the diagnostic MRI without anesthesia in the groups with and without mock scanner training. These will be compared utilizing T-test and Kaplan-Meier Analysis.