Ultrasound guidance for difficult lumbar puncture in children: pearls and pitfalls.

Pediatric lumbar puncture can be challenging or unsuccessful for several reasons. At the same time, the excellent sonographic window into the pediatric spine provides a distinct opportunity for ultrasound-guided lumbar puncture. Minimal cerebrospinal fluid and thecal displacement by subdural or epidural hematomas are common after failed clinical attempts. Ultrasound is useful for determining a safe infraconal level for subarachnoid access. Real-time guidance increases not only the success rate but also the safety of diagnostic lumbar puncture and injections for chemotherapy and myelography. In this article, we discuss clinical and technical factors for ultrasound-guided pediatric lumbar puncture.

Pre- and postnatal findings in a boy with duplication of the bladder and intestine: report and review.

We describe a boy with a septated bladder and dilated bowel loop found on prenatal ultrasonography. Subsequent prenatal MRI diagnosed a probable caudal duplication anomaly. Postnatal investigations and surgical findings confirmed duplication of bladder, urethra, and bowel from distal ileum to rectum. This is the first reported case of combined bladder and colon duplication suspected antenatally with thorough imaging investigations including fetal MRI. While diagnosis of bladder duplication has been described, prenatal diagnosis of intestinal duplication has not been documented previously. This report of prenatal imaging with surgical and pathological correlation contributes to our detailed understanding of the spectrum of anatomy seen in caudal duplication anomaly.

Diagnostic imaging of posterior fossa anomalies in the fetus.

Ultrasound and magnetic resonance imaging are the two imaging modalities used in the assessment of the fetus. Ultrasound is the primary imaging modality, whereas magnetic resonance is used in cases of diagnostic uncertainty. Both techniques have advantages and disadvantages and therefore they are complementary. Standard axial ultrasound views of the posterior fossa are used for routine scanning for fetal anomalies, with additional orthogonal views directly and indirectly obtainable using three-dimensional ultrasound techniques. Magnetic resonance imaging allows not only direct orthogonal imaging planes, but also tissue characterization, for example to search for blood breakdown products. We review the nomenclature of several posterior fossa anomalies using standardized criteria, and we review cerebellar abnormalities based on an etiologic classification.