Mr750 discovery mri system

With institutional review board approval (IRB-28674) and informed consent, experiments were conducted on two healthy adult volunteers (one male 32 years old and one women 30 years old) using a 3T whole-body GE MR750 Discovery MRI system (GE Healthcare, Milwaukee, WI, gradient strength=50 mT/m and slew rate=200 T/m/s) and an eight-channel head coil. With IRB approval, data were also acquired on two patients during clinical diagnostic scans: 1) one with abnormal anatomy (4Y male), clinical symptoms of headaches and cerebellar ataxia, and obstructive features at the craniocervical junction, including peg-like, low-lying cerebellar tonsils and narrow foramen magnum, associated with Chiari I malformation and basilar invagination; and 2) one control with normal structural MRI (3Y male).

At the beginning of the study, neuroimaging data were acquired on a 1.5T GE Signa Excite MR scanner (scanner 1). Six years later, the 1.5T MRI system was decommissioned and we used a 3T GE MR750 Discovery MRI system (scanner 2). Baseline and follow-up scans on scanner 2 were collected with different head coils. Scan parameters and scans collected on each scanner and head coil are presented in the Supplemental Material. In all but three cases, mothers were scanned on the same scanner as their daughters’ first scan. An analysis of variance (ANOVA) yielded no significant differences in family income as a function of scanner (dummy coded scanner 1, scanner 2, or both; income: F(2,98) = 0.13, p = 0.880), though there was a marginal difference in average years of parental education (F(2,97) = 3.03, p = 0.053). Post hoc Fisher’s least significant differences (LSD) tests revealed that the 32 girls who were scanned with scanner 2 only had more highly educated parents than those who were scanned only at scanner 1 (p = 0.021) and marginally more than those who were scanned at both facilities (p = 0.067).