In-utero human fetal brain MRI
it is anticipated that gravid women will be recruited and matched to a neonatal cohort based on gestational age.
Seventy gravid women between 26 and 40 gestational weeks will be recruited in partnership with obstetrics and Gynecology in Parkland Health and Hospital System (PHHS) and Children's Medical Center (CMC) at Dallas. Recruitment will include 7 fetuses within each gestational week. Specifically, 7 each of the following subgroups:
1. 26weeks 0 day-26weeks 6 days,
2. 27weeks 0 day-27weeks 6 days,
3. 28weeks 0 day-28weeks 6 days,
4. 29weeks 0 day-29weeks 6 days,
5. 30weeks 0 day-30weeks 6 days,
6. 31weeks 0 day-31weeks 6 days,
7. 32weeks 0 day-32weeks 6 days,
8. 33weeks 0 day-33weeks 6 days,
9. 34weeks 0 day-34weeks 6 days,
10. 35weeks 0 day-35weeks 6 days,
one subject may be recruited between the ages of 36 weeks 0 day and 40 weeks 0 day gestational age.
assignment of gestational age will be based on combined last menstrual history and 1st trimester ultrasound, as well as recent 3rd trimester ultrasound.
once these pregnant mothers are identified and consented, structural MRi data will be acquired with Philips 1.5 T located at Rogers imaging Center at ne building of university of Texas Southwestern Medical Center. note that to avoid large SaR (Specific absorption Rate) of the in-utero MRi, 1.5 T wide-bore magnet, instead of 3 T magnet, will be used. During the MR scan, the phased array cardiac coil will be wrapped around the mother's abdomen. The maternal imaging position will be supine or the left lateral decubitus position. one investigator (DT) has had experience in successful imaging of over 2,000 fetal MR's over the past 10 years
DTi: a single-shot echo-planar imaging (ePi) sequence with SenSe parallel imaging scheme (SenSitivity encoding, reduction factor [?]2.5) will be used. T2-weighted imaging: Co-registered T2 weighted image, using a single spin echo sequence, will be acquired with the echo time 120ms. The T2 weighted imaging acquisitions will take approximately 10 minutes
after MRi data acquisition, the data CDs will be obtained by MR tech at Rogers imaging Center. Datasets will be de-identified and assigned a study number. The identification information and study number will be stored in a password-protected projects folder in the Radiology Department R drive. The de-identified data will be distributed to members of the Pi's team for post-processing. after tensor fitting of DTi data, two important data analyses will be conducted. First, the white matter tracts will be three-dimensionally reconstructed with DTi tractography. Second, the cerebral wall will be manually segmented to delineate the thickness and fractional anisotropy at the three layers from inside to outside, inner layer, subplate and cortical plate. all post-processing of MRi including DTi will be conducted with the de-identified data.
Follow-up study for 2-year-old: a widely used method to ensure normal brain development is the one with combined MRi and neuropsychological tests when the infants are 2 years old. PHHS has a good follow-up system. We will use the PHHS follow-up system to contact the moms around 2 years after the in-utero MRi. in this follow-up study, moms will bring their toddlers to the Children's at Dallas where both MRi and neurospsychological tests will be conducted. The MRi will include a DTi, a T1-weighted and a T2-weighted imaging sequence with less than 25 minutes in total. a pediatric neuropsychological professional will use the routine clinical protocol to perform the neuropsychological test. $100 will be paid to the mom for the follow-up visit.
Healthy gravid women with no complications of pregnancy whose fetuses are 26 to 40 weeks based on last menstrual period (LMP) and ultrasound criteria who have a normal evaluation as assessed by AIUM criteria are eligible for the study. An attempt will be made to enlist equal numbers of males and female fetuses and reflect the ethnicity of the PHHS population.