Feasibility and Success Rate of a Fetal MRI and MR Spectroscopy Research Protocol Performed at Term Using a 3.0-Tesla Scanner

Abstract

Objectives: To report the feasibility and main factors affecting the success of a fetal magnetic resonance imaging (MRI) and MR spectroscopy (MRS) research protocol performed at term using a 3-tesla scanner. Methods: Pregnant patients at term underwent an MRI. Specific measures were taken to prevent maternal discomfort and distress, such as detailed counseling and maternal repositioning if needed. MRS data were acquired from the frontal lobe and basal ganglia, and processed applying quality control criteria. Results: The mean gestational age at MRI was 37.4 ± 0.9 weeks. From a total of 245 patients that showed up for the MRI, 11 referred claustrophobia which prevented the test from starting, and 30 patients started the test but decided to discontinue due to discomfort. Thus, the examination was complete in 204 patients. MRS data could be obtained in 170 cases from the frontal lobe and 165 cases from the basal ganglia, of which 52.4 and 68.6%, respectively, complied with our defined quality criteria. The mean scanning time was 34:16 ± 9:30 min:s after excluding those cases presenting initial intolerance to the test. Minor abnormalities were described in 11 MRI reports. Conclusions: The fetal MRI/MRS protocol was feasible and generally well tolerated at term on a 3-tesla scanner, but a significant number of cases were lost to analysis. The rate of patients that eventually provided usable research information was 95.5% for anatomical examination and 52.4-68.6% for MRS. This information should be taken into account in the design of fetal brain MRI studies.