Purpose or Case Report: T1-weighted imaging is a routine sequence in fetal MR imaging, which allows vicarious imaging of the fetal colon due to the short T1 signal characteristics of meconium. The purpose of this study was to compare image quality and acquisition time of a T1-mDixon sequence relative to a standard fast T1 gradient echo sequence, and to determine whether bowel pathology (such as colon hernaition in congenitial diaphragmatic hernia) can be more quickly and clearly delineated with T1-mDIXON.
Methods & Materials: This is a retrospective review of all sequential fetal MR cases performed in our institution to present. Inclusion criteria: all cases where both sequences have been acquired. Exclusion criteria: Limited or incomplete studies or where both sequences were not performed. All fetal MRIs were performed on 1.5 T Siemens machine, and reviewed by three Radiologists experienced in fetal MRI. Both sequence types were scored on five point (quality) scale to enable comparison. If multiple acquisitions of a sequence were performed in the same patient, the scores were averaged. The two groups' scores were compared using qualitative statistical analysis (t-test). Acquisition time of each sequence per patient was also compared.
Results: The first 27 patients were exlcuded because the mDIXON sequence was not included in the routine fetal MRI protocol at that time. 3 patients were excluded because the exam was limited and the sequence was not run. A total of 28 patients had each sequence performed at least once and were included in the study group. Preliminary results indicate that T1-mDIXON is a significantly faster sequence and results in improved image quality (both in-plane and out-of-plane resolution).
Conclusions: T1-mDIXON provides added value in our fetal MR imaging protocol by improving image quality of the fetal colon and reducing acquisition time.