The macrocystic structure was located in the midline and extended way down into the pelvis towards the perineal area. It displayed an incomplete midline septum. Hypointense deposits are seen within. Its shape and location on the midline, behind the bladder, are very suggestive of a hydrometrocolpos with a partial uterine septum.
The bladder was best seen on sagittal and axial view. It was pushed to the front by what appears to be a hydrometrocolpos and was less than half-full. In contrast, there was dilation of both ureters and both kidney pelvis above the hydrometrocolpos. Either there was a mass effect on both ureters, either there was a low-urinary-tract-obstruction (LUTO) with "valve-effect" towards the colpos.
The meconium has a remarkable T1 hyperintense physiological signal, which is very handy to follow the large bowel. On axial, sagittal, and coronal view, no hyperintense T1 meconium was seen in the pelvis. The large bowel likely ended 4 centimetres above the perineal skin: most likely a high-type anorectal malformation. There was no bowel dilation nor enterolithiasis.
Spine and spinal cord showed normal MRI appearance.