Does the Addition of a "Black Bone" Sequence to a Fast Multisequence Trauma MR Protocol Allow MRI to Replace CT after Traumatic Brain Injury in Children?

BACKGROUND AND PURPOSE: Head CT is the current neuroimaging tool of choice in acute evaluation of pediatric head trauma. The potential cancer risks of CT-related ionizing radiation should limit its use in children. We evaluated the role of MR imaging, including a "black bone" sequence, compared with CT in detecting skull fractures and intracranial hemorrhages in children with acute head trauma. MATERIALS AND METHODS: We performed a retrospective evaluation of 2D head CT and brain MR imaging studies including the black bone sequence of children with head trauma. Two experienced pediatric neuroradiologists in consensus created the standard of reference. Another pediatric neuroradiologist blinded to the diagnosis evaluated brain MR images and head CT images in 2 separate sessions. The presence of skull fractures and intracranial posttraumatic hemorrhages was evaluated. We calculated the sensitivity and specificity of CT and MR imaging with the black bone sequence in the diagnosis of skull fractures and intracranial hemorrhages. RESULTS: Twenty-eight children (24 boys; mean age, 4.89 years; range, 0-15.5 years) with head trauma were included. MR imaging with the black bone sequence revealed lower sensitivity (66.7% versus 100%) and specificity (87.5% versus 100%) in identifying skull fractures. Four of 6 incorrectly interpreted black bone MR imaging studies showed cranial sutures being misinterpreted as skull fractures and vice versa. CONCLUSIONS: Our preliminary results show that brain MR imaging complemented by a black bone sequence is a promising nonionizing alternative to head CT for the assessment of skull fractures in children. However, accuracy in the detection of linear fractures in young children and fractures of aerated bone remains limited.

Transfontanellar duplex brain ultrasonography resistive indices as a prognostic tool in neonatal hypoxic-ischemic encephalopathy before and after treatment with therapeutic hypothermia.

OBJECTIVE: Prior to therapeutic hypothermia (that is, cooling), transfontanellar duplex brain sonography resistive indices (RI) were studied as a bedside non-invasive measures of cerebral hemodynamics in neonates who suffered from hypoxic-ischemic encephalopathy (HIE). We compared pre- and post-cooling RI values and examined the relationships between RI values and specific long-term neurodevelopmental outcomes. STUDY DESIGN: Transfontanellar duplex brain sonography, including RI, were obtained for 28 neonates prior to cooling and for 20 neonates following cooling. All RI values were sampled in the anterior cerebral artery at the beginning of each ultrasound study. Neurodevelopmental assessment was conducted between ages 20-32 months with the Mullen Scale of Early Learning. The relationships between pre- and post-cooling RI and cognitive and motor outcomes were studied. RESULT: Neonates with RI values <0.60 prior to and following cooling were more likely to die or have severe neurodevelopmental disability by ages 20-32 months than those with RI>0.60. Lower RI values were associated with specific neurodevelopmental deficits in motor skill attainment. CONCLUSION: Pre- and post-cooling transfontanellar duplex brain sonography RI values may be a useful prognostic tool, in conjunction with other clinical information, for neonates diagnosed with HIE. The results of this study suggest that further study of the prognostic value of RI values for short- and long-term outcomes is warranted.

Susceptibility-weighted imaging in pediatric arterial ischemic stroke: a valuable alternative for the noninvasive evaluation of altered cerebral hemodynamics.

BACKGROUND AND PURPOSE: SWI provides information about blood oxygenation levels in intracranial vessels. Prior reports have shown that SWI focusing on venous drainage can provide noninvasive information about the degree of brain perfusion in pediatric arterial ischemic stroke. We aimed to evaluate the influence of the SWI venous signal pattern in predicting stroke evolution and the development of malignant edema in a large cohort of children with arterial ischemic stroke. MATERIALS AND METHODS: A semiquantitative analysis of venous signal intensity on SWI and diffusion characteristics on DTI was performed in 16 vascular territories. The mismatch between areas with SWI-hypointense venous signal and restricted diffusion was correlated with stroke progression on follow-up. SWI-hyperintense signal was correlated with the development of malignant edema. RESULTS: We included 24 children with a confirmed diagnosis of pediatric arterial ischemic stroke. Follow-up images were available for 14/24 children. MCA stroke progression on follow-up was observed in 5/6 children, with 2/8 children without mismatch between areas of initial SWI hypointense venous signal and areas of restricted diffusion on DTI. This mismatch showed a statistically significant association (P = .03) for infarct progression. Postischemic malignant edema developed in 2/10 children with and 0/14 children without SWI-hyperintense venous signal on initial SWI (P = .07). CONCLUSIONS: SWI-DTI mismatch predicts stroke progression in pediatric arterial ischemic stroke. SWI-hyperintense signal is not useful for predicting the development of malignant edema. SWI should be routinely added to the neuroimaging diagnostic protocol of pediatric arterial ischemic stroke.

Neonatal neuroimaging findings in congenital myotonic dystrophy.

We report on a preterm neonate of 30 weeks gestational age who presented with marked muscular hypotonia and severe respiratory failure at birth and was diagnosed with congenital myotonic dystrophy. Neuroimaging at 36 gestational weeks demonstrated diffuse T2-hyperintense signal of the supratentorial white matter and a simplified gyration and sulcation pattern. Follow-up imaging showed progressive myelination, brain maturation and decrease in T2-signal of the white matter. We discuss possible pathomechanisms for white matter signal abnormalities in this neonate.

Feasibility of an optimized MR enterography protocol in the evaluation of pediatric inflammatory bowel disease.

Cross-sectional imaging forms an important alternative and complimentary tool to endoscopy in aiding the clinician with diagnosis and management of pediatric inflammatory bowel disease (IBD). The purpose of the study was to evaluate the feasibility of an optimized Magnetic Resonance Enterography (MRE) protocol in the evaluation of patients with suspected IBD. 31 children (18 boys and 13 girls) were evaluated by a pediatric gastroenterologist prior to MRE and given a grading for clinical severity of disease. Imaging was then performed with oral contrast and a tailored protocol using fast T1/T2 weighted pulse sequences. Additionally, contrast and glucagon were administered intravenously. Imaging findings were then correlated with the clinical data. Excellent distension was achieved in the small bowel. The majority of the studies were of diagnostic quality with no motion artifacts. Imaging findings showed statistically significant correlation with disease activity. An optimized pediatric MRE protocol is feasible and correlates well with clinical disease activity. This in turn aids the clinician in the management of children with this chronic debilitating disease.