Hirschsprung disease in the premature newborn: a population based study and 40-year single center experience.

BACKGROUND/PURPOSE: Understanding of Hirschsprung disease (HD) in premature newborns (PHD) is anecdotal. We have sought in this study to identify the demographic and clinical features of PHD. METHODS: All patients with HD 1970-2011 treated at our tertiary care children's hospital were identified. Patients with biopsy confirmed HD and EGA <37weeks were selected for further review. Prenatal and birth data, demographics, clinical signs, radiologic and pathologic data, and operative interventions were examined. The occurrence of PHD was observed using data from the Utah Department of Health database 1997-2011. RESULTS: 404 patients with HD from 1970 to 2011 were treated. Twenty-seven (6.7%) had PHD. Mean birth weight in PHD was 2196grams and mean gestational age 34 (range 29-36)weeks. Seven patients had Down syndrome. Nonchromosomal anomalies occurred in 25%. Median time from birth to biopsy diagnosis was 42days (range 2-316days). The most common presenting signs were abdominal distension and bilious emesis. The HD incidence in Utah for all births was 1/4322 (0.023%) and for premature infants 1/3885 (0.027%). CONCLUSIONS: PHD are similar to term infants with HD. Diagnosis of HD is often delayed in premature newborns, and associated anomalies are more common.

Implementing an ultrasound-based protocol for diagnosing appendicitis while maintaining diagnostic accuracy.

BACKGROUND: The use of ultrasound to diagnose appendicitis in children is well-documented but not universally employed outside of pediatric academic centers, especially in the United States. Various obstacles make it difficult for institutions and radiologists to abandon a successful and accurate CT-based imaging protocol in favor of a US-based protocol. OBJECTIVE: To describe how we overcame barriers to implementing a US-based appendicitis protocol among a large group of nonacademic private-practice pediatric radiologists while maintaining diagnostic accuracy and decreasing medical costs. MATERIALS AND METHODS: A multidisciplinary team of physicians (pediatric surgery, pediatric emergency medicine and pediatric radiology) approved an imaging protocol using US as the primary modality to evaluate suspected appendicitis with CT for equivocal cases. The protocol addressed potential bias against US and accommodated for institutional limitations of radiologist and sonographer experience and availability. Radiologists coded US reports according to the probability of appendicitis. Radiology reports were compared with clinical outcomes to assess diagnostic accuracy. During the study period, physicians from each group were apprised of the interim US protocol accuracy results. Problematic cases were discussed openly. RESULTS: A total of 512 children were enrolled and underwent US for evaluation of appendicitis over a 30-month period. Diagnostic accuracy was comparable to published results for combined US/CT protocols. Comparing the first 12 months to the last 12 months of the study period, the proportion of children achieving an unequivocal US result increased from 30% (51/169) to 53% (149/282) and the proportion of children undergoing surgery based solely on US findings increased from 55% (23/42) to 84% (92/109). Overall, 63% (325/512) of patients in the protocol did not require a CT. Total patient costs were reduced by $30,182 annually. CONCLUSION: We overcame several barriers to implementing a US protocol. During the study period our ability to visualize the appendix with US increased and utilization of CT decreased. Our overall diagnostic accuracy with the US-based protocol was comparable to other published results and remained unchanged throughout the study.

The pathogenesis and imaging of the tuberous sclerosis complex.

Tuberous sclerosis complex (TSC) is an autosomal-dominant disorder characterized by the formation of hamartomatous lesions in multiple organ systems. It is the second most common neurocutaneous syndrome after neurofibromatosis type 1 and has been recognized since the late 1800s. Although the disease has complete penetrance, there is also high phenotypic variability: some patients have obvious signs at birth, while others remain undiagnosed for many years. In addition to skin lesions, TSC patients develop numerous brain lesions, angiomyolipoma (AMLs), lymphangiomyomatosis (LAM) in the lungs, cardiac rhabdomyomas, skeletal lesions, and vascular anomalies, all of which are well seen with medical imaging. Our knowledge of TSC genetics and pathophysiology has expanded dramatically in recent years: two genetic loci were discovered in the 1990s and recent elucidation of TSC's interaction with the mTOR pathway has changed how we manage the disease. Meanwhile, medical imaging is playing an increasingly important role in the diagnosis, management, and treatment of TSC. We provide an update on the genetics and pathophysiology of TSC, review its clinical manifestations, and explore the breadth of imaging features in each organ system, from prenatal detection of cardiac rhabdomyomas to monitoring rapamycin therapy to treatment of AMLs by interventional radiology.

Neuroimaging of herpesvirus infections in children.

Six members of the herpesvirus family cause well-described neurologic disease in children: herpes simplex virus-1 (HSV-1), herpes simplex virus-2 (HSV-2), varicella-zoster (VZV), Epstein-Barr (EBV), cytomegalovirus (CMV), and human herpes virus-6 (HHV-6). When herpesviruses infect the central nervous system (CNS), the clinical presentation is non-specific and often confounding. The clinical urgency is often underscored by progressive neurologic deficits, seizures, or even death, and prompt diagnosis and treatment rely heavily on neuroimaging. This review focuses on the spectrum of cerebral manifestations caused by these viruses, particularly on non-congenital presentations. Recent advances in our understanding of these viruses are discussed, including new polymerase chain reaction techniques that allow parallel detection, which has improved our recognition that the herpesviruses are neurotropic and involve the CNS more often than previously thought. Evolving knowledge has also better elucidated viral neuropathology, particularly the role of VZV vasculitis in the brain, HHV-6 in febrile seizures, and herpesvirus reactivation in immunosuppressed patients. The virology, clinical course, and CNS manifestations of each virus are reviewed, followed by descriptions of neuroimaging findings when these agents infect the brain. Characteristic but often subtle imaging findings are discussed, as well as technical pearls covering appropriate use of MRI and MRI adjuncts to help differentiate viral infection from mimics.