Magnetic resonance imaging of fetal pelvic cysts

A Case of Multicystic Dysplastic Kidney Presenting as a Single Midline Pelvic Cyst

We present an unusual case of a female neonate presenting with a single midline pelvic cyst. Prenatal imaging was suggestive of multicystic dysplastic kidney (MCDK), but postnatal imaging was atypical for this diagnosis given the location and singular cyst noted. The patient ultimately underwent surgical exploration and was diagnosed with an ectopic MCDK. Ectopic MCDK should be considered in the differential diagnosis of unilocular cystic pelvic lesions identified in the perinatal period.

Approach to the postnatal sonographic evaluation of prenatally detected abdominopelvic cysts

Prenatally detected abdominal and pelvic masses are commonly cystic in morphology and usually seen on mid-trimester sonography. Sonography is the favored imaging modality for the postnatal evaluation of these lesions in newborns, given its availability, low cost, lack of ionizing radiation, lack of sedation, and high spatial resolution in small patients. The differential diagnosis of abdominopelvic cystic masses in newborns is broad given that they can arise from many organs and may have overlapping features on imaging. This article illustrates an approach to the postnatal sonographic evaluation of prenatally detected cystic abdominal and pelvic masses based on their anatomic location and distinctive sonographic characteristics, which can aid in an accurate diagnosis and guide appropriate management.

Imaging of anorectal malformations in utero

PURPOSE

To document the imaging findings suggestive of anorectal malformation (ARMs) on prenatal US and MRI.

METHODS

Retrospective evaluation of the screening US and prenatal MRI exams of the rectum and ano-perineal region in normal fetuses and in patients with ARMs.

RESULTS

Examples showing the normal rectal and anoperineal anatomy on prenatal US and MRI exams and the imaging findings observed in different types of confirmed ARMS.

CONCLUSIONS

Prenatal diagnosis of ARMs requires both a systematic evaluation of the fetal pelvis and perineum and an appropriate knowledge of its suggestive imaging findings.