Whole-Spine MRI in Children With Suspected Abusive Head Trauma.

BACKGROUND. Abusive head trauma (AHT) in children has recently been associated with findings on cervical spine MRI. OBJECTIVE. The purpose of this study was to evaluate whether whole-spine MRI in children with suspected AHT shows additional abnormalities not identified on cervical spine MRI. METHODS. This retrospective study included 256 children younger than 3 years old (170 boys, 86 girls; mean age, 5.9 months) who underwent skeletal survey and head MRI for suspected child abuse from January 2019 to December 2020. Per institutional protocol, children with suspected AHT also underwent whole-spine MRI. AHT diagnoses were established by a combination of clinical information from medical record review and injuries described in reports from skeletal survey, head MRI, and head CT (if performed). Two pediatric neuroradiologists independently reviewed whole-spine MRI examinations for presence and level of intraspinal hemorrhage (classified as subarachnoid, subdural, or epidural), ligamentous injury, spinal cord edema, and vertebral fractures; subdural hematoma, epidural hematoma, ligamentous injury, and fracture unidentified by skeletal survey were considered major findings. Interobserver agreement was assessed; a third radiologist resolved discrepancies. Findings were summarized with attention to injuries isolated to the thoracolumbar spine. RESULTS. A total of 148 of 256 (57.8%) children underwent whole-spine MRI. AHT was diagnosed in 79 of 148 (53.4%) children who underwent whole-spine MRI versus in 2 of 108 (1.9%) who did not undergo whole-spine MRI (p < .001). Interobserver agreement, expressed as kappa coefficient, was 0.90 for intraspinal hemorrhage, 0.69 for ligamentous injury, 0.66 for spinal cord edema, and 0.95 for fracture. A total of 57 of 148 (38.5%) whole-spine MRI examinations showed injuries, and 34 of 148 (23.0%) showed injuries localized to the thoracolumbar spine. A total of 47 of 148 (31.8%) whole-spine MRI examinations showed major findings, of which 24 (51.1%) were localized to the thoracolumbar spine. Isolated thoracolumbar injuries included 23 of 34 spinal subdural hematomas, 2 of 3 spinal epidural hematomas, and 9 of 11 vertebral fractures, including five fractures not identified by skeletal survey. Diagnosis of AHT was more common in children with positive, versus negative, whole-spine MRI examinations (76.8% vs 39.1%; p < .001). CONCLUSION. In children with suspected AHT, whole-spine MRI commonly shows isolated thoracolumbar injuries. CLINICAL IMPACT. The results support performing whole-spine MRI rather than cervical spine MRI in children with suspected AHT.

Resting state functional MRI in infants with prenatal opioid exposure-a pilot study.

PURPOSE: Exposure to prenatal opioids may adversely impact the developing brain networks. The aim of this pilot study was to evaluate alterations in amygdalar functional connectivity in human infants with prenatal opioid exposure. METHODS: In this prospective IRB approved study, we performed resting state functional MRI (rs-fMRI) in 10 infants with prenatal opioid exposure and 12 infants without prenatal drug exposure at < 48 weeks corrected gestational age. Following standard preprocessing, we performed seed-based functional connectivity analysis with the right and left amygdala as the regions of interest after correcting for maternal depression and infant sex. We compared functional connectivity of the amygdala network between infants with and without prenatal opioid exposure. RESULTS: There were significant differences in connectivity of the amygdala seed regions to the several cortical regions including the medial prefrontal cortex in infants who had prenatal opioid exposure when compared with opioid naïve infants. CONCLUSION: This finding of increased amygdala functional connectivity in infants with in utero opioid exposure suggests a potential role of maternal opioid exposure on infants' altered amygdala function. This association with prenatal exposure needs to be replicated in future larger studies.

A multifactorial severity score for left congenital diaphragmatic hernia in a high-risk population using fetal magnetic resonance imaging.

BACKGROUND: Adverse outcomes for infants born with left congenital diaphragmatic hernia (CDH) have been correlated with fetal imaging findings. OBJECTIVE: We sought to corroborate these correlations in a high-risk cohort and describe a predictive mortality algorithm combining multiple imaging biomarkers for use in prenatal counseling. MATERIALS AND METHODS: We reviewed fetal MRI examinations at our institution from 2004 to 2016 demonstrating left-side CDH. MRI findings, hospital course and outcomes were recorded and analyzed using bivariate and multivariable analysis. We generated a receiver operating curve (ROC) to determine a cut-off relation for mortality. Finally, we created a predictive mortality calculator. RESULTS: Of 41 fetuses included in this high-risk cohort, 41% survived. Per bivariate analysis, observed-to-expected total fetal lung volume (P=0.007), intrathoracic position of the stomach (P=0.049), and extracorporeal membrane oxygenation (ECMO) requirement (P<0.001) were significantly associated with infant mortality. Youden J statistic optimized the ROC for mortality at 24% observed-to-expected total fetal lung volume (sensitivity 64%, specificity 82%, area under the curve 0.72). On multivariable analysis, observed-to-expected total fetal lung volume ± 24% was predictive of mortality (adjusted odds ratio, 95% confidence interval: 0.09 [0.02, 0.55]; P=0.008). We derived a novel mortality prediction calculator from this analysis. CONCLUSION: In this high-risk cohort, decreased observed-to-expected total fetal lung volume and stomach herniation were significantly associated with mortality. The novel predictive mortality calculator utilizes information from fetal MR imaging and provides prognostic information for health care providers. Creation of similar predictive tools by other institutions, using their distinct populations, might prove useful in family counseling, especially where there are discordant imaging findings.

Small-Conductance Calcium-Activated Potassium Current in Normal Rabbit Cardiac Purkinje Cells.

BACKGROUND: Purkinje cells (PCs) are important in cardiac arrhythmogenesis. Whether small-conductance calcium-activated potassium (SK) channels are present in PCs remains unclear. We tested the hypotheses that subtype 2 SK (SK2) channel proteins and apamin-sensitive SK currents are abundantly present in PCs. METHODS AND RESULTS: We studied 25 normal rabbit ventricles, including 13 patch-clamp studies, 4 for Western blotting, and 8 for immunohistochemical staining. Transmembrane action potentials were recorded in current-clamp mode using the perforated-patch technique. For PCs, the apamin (100 nmol/L) significantly prolonged action potential duration measured to 80% repolarization by an average of 10.4 ms (95% CI, 0.11-20.72) (n=9, P=0.047). Voltage-clamp study showed that apamin-sensitive SK current density was significantly larger in PCs compared with ventricular myocytes at potentials ≥0 mV. Western blotting of SK2 expression showed that the SK2 protein expression in the midmyocardium was 58% (P=0.028) and the epicardium was 50% (P=0.018) of that in the pseudotendons. Immunostaining of SK2 protein showed that PCs stained stronger than ventricular myocytes. Confocal microscope study showed SK2 protein was distributed to the periphery of the PCs. CONCLUSIONS: SK2 proteins are more abundantly present in the PCs than in the ventricular myocytes of normal rabbit ventricles. Apamin-sensitive SK current is important in ventricular repolarization of normal PCs.