Antenatal magnetic resonance imaging is useful in providing predictive values for surgical procedures in abdominal wall defects

Abstract

Background Antenatal magnetic resonance imaging (MRI) is useful for the diagnosis of abdominal wall defects. Its predictive value concerning the possibility of primary closure of the abdominal wall, however, has so far not been reported. Methods Between August 2001 and November 2004, antenatal MRI was performed on 9 patients with abdominal wall defects in whom surgical repair was performed immediately after birth. Areas of the abdominal cavity and exteriorized viscera were manually traced from both sagittal and axial MR images, and the data were further transmitted to a Workstation for MRI Volumetry (Advantage Windows 4.1, General Electric Medical Systems, Milwaukee, Wis). We examined the exteriorized ratio (ER), which is calculated by dividing the absolute volume of the abdominal cavity by that of the exteriorized viscera, and evaluated the predictive value by a retrospective comparison with surgical procedure. Results In the primary closure group (n = 5), mean values of ER were 0.33 ± 0.31 from axial and 0.45 ± 0.31 from sagittal MR images. In contrast, in the staged closure group (n = 4), mean values of ER were 1.39 ± 0.40 from axial and 1.34 ± 0.42 from sagittal MR images. There was a significant difference ( P < .05) between the 2 groups for both sets of images. The ER obtained from antenatal MRI correlated well with surgical procedure. Conclusions The ER might be useful for antenatal counseling, planning for delivery, and prediction of the most likely surgical procedure.