Single uterine axial fast acquisition magnetic resonance fetal survey: is it feasible?
OBJECTIVE
To determine which non-biometric components of the ultrasound fetal survey can routinely be seen on a single fast acquisition magnetic resonance (MR) sequence aligned axial to the maternal uterus.


METHODS
The non-biometric components of the routine fetal ultrasound examination were applied retrospectively to the initial MR single-shot fast spin-echo acquisition aligned axial to the maternal uterus in the normal fetus to determine whether these parameters could be routinely evaluated. Nineteen women with anatomically normal fetuses had a total of 31 MR studies performed for fetal or maternal indications, either as part of an indicated examination or as part of a study protocol approved by the institutional review board. The images in these 31 MR studies were reviewed by two independent examiners who were blinded to the other's assessment; concordance was necessary for a component to be adequately assessed. The Wilcoxon rank sum test was used to determine the effect of gestational age and fetal lie on the ability to assess non-biometric parameters.


RESULTS
Assessment was possible in 85% of the non-biometric parameters. Cord insertion, external genitalia and the four-chamber view of the heart were most problematic. In only two cases was the four-chamber view of the heart identified. Longitudinal lie allowed significantly more parameters (82%) to be evaluated than transverse lie (45%) (p < 0.003). No difference based on gestational age was found.


CONCLUSIONS
A single fast acquisition axial MR sequence can evaluate 85% of the non-biometric components of the fetal ultrasound survey. Fetal lie is an important confounder in the ability to resolve fetal anatomy with a single MR axial uterine acquisition.
Zaretsky
M V
MV
Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9032, USA.
Ramus
R M
RM
Twickler
D M
DM
D000328:Adult; D000653:Amniotic Fluid / Q000000981:diagnostic imaging; D005260:Female; D005333:Fetus / Q000033:anatomy & histology*; D005865:Gestational Age; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010388:Pelvis / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D010920:Placenta / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D011247:Pregnancy; D011264:Pregnancy Trimesters; D011296:Prenatal Diagnosis / Q000379:methods*; D014463:Ultrasonography; D014599:Uterus / Q000033:anatomy & histology* / Q000000981:diagnostic imaging