A Novel Maneuver to Treat Refractory Atelectasis in Mechanically Ventilated Children.

We developed a novel airway clearance and lung recruitment maneuver for children with refractory unilateral atelectasis undergoing invasive mechanical ventilation. In this retrospective, single-center, proof of concept study, we describe the steps involved in this novel maneuver and evaluate its effectiveness in 15 patients through objective quantitation of changes in respiratory system compliance and in the degree of atelectasis assessed by a validated Modified Radiology Atelectasis Score. Compared with the premaneuver baseline, the median atelectasis score improved significantly following the maneuver (9 [7.5-10] vs. 1 [0-3.3], respectively, p < 0.01). Likewise, dynamic compliance was significantly higher following the maneuver (0.3 [0.32-0.44] vs. 0.61 [0.53-0.69] mL/kg/cm H 2 O, respectively, p < 0.01). No patients required a bronchoscopy. This simple and effective maneuver resulted in a significant improvement in the degree of atelectasis and dynamic compliance in this cohort of mechanically ventilated children with refractory unilateral atelectasis.

Risk Factors for Brain Injury in Newborns Treated with Extracorporeal Membrane Oxygenation.

OBJECTIVE: This study aimed to assess the association of clinical risk factors with severity of magnetic resonance imaging (MRI) brain injury in neonatal extracorporeal membrane oxygenation (ECMO) patients. STUDY DESIGN: This is a single-center retrospective study conducted at an outborn level IV neonatal intensive care unit in a free-standing academic children's hospital. Clinical and MRI data from neonates treated with ECMO between 2005 and 2015 were reviewed. MRI injury was graded by two radiologists according to a modified scoring system that assesses parenchymal injury, extra-axial hemorrhage, and cerebrospinal fluid spaces. MRI severity was classified as none (score = 0), mild/moderate (score = 1-13.5), and severe (score ≥ 14). The relationship between selected risk factors and MRI severity was assessed by Chi-square, analysis of variance, and Kruskal-Wallis tests where appropriate. Combinative predictive ability of significant risk factors was assessed by logistic regression analyses. RESULTS: MRI data were assessed in 81 neonates treated with ECMO. Veno-arterial (VA) patients had more severe injury compared with veno-venous patients. There was a trend toward less severe injury over time. After controlling for covariates, duration of ECMO remained significantly associated with brain injury, and the risk for severe injury was significantly increased in patients on ECMO beyond 210 hours. CONCLUSION: Risk for brain injury is increased with VA ECMO and with longer duration of ECMO. Improvements in care may be leading to decreasing incidence of brain injury in neonatal ECMO patients. KEY POINTS: · Veno-arterial ECMO is associated with more brain injury by MRI compared with veno-venous ECMO.. · Longer duration of ECMO is significantly associated with severe brain injury by MRI.. · Risk for neurologic injury may be decreasing over time with advances in neonatal ECMO..

A comparison study of size-specific dose estimate calculation methods.

BACKGROUND: The size-specific dose estimate (SSDE) has emerged as an improved metric for use by medical physicists and radiologists for estimating individual patient dose. Several methods of calculating SSDE have been described, ranging from patient thickness or attenuation-based (automated and manual) measurements to weight-based techniques. OBJECTIVE: To compare the accuracy of thickness vs. weight measurement of body size to allow for the calculation of the size-specific dose estimate (SSDE) in pediatric body CT. MATERIALS AND METHODS: We retrospectively identified 109 pediatric body CT examinations for SSDE calculation. We examined two automated methods measuring a series of level-specific diameters of the patient's body: method A used the effective diameter and method B used the water-equivalent diameter. Two manual methods measured patient diameter at two predetermined levels: the superior endplate of L2, where body width is typically most thin, and the superior femoral head or iliac crest (for scans that did not include the pelvis), where body width is typically most thick; method C averaged lateral measurements at these two levels from the CT projection scan, and method D averaged lateral and anteroposterior measurements at the same two levels from the axial CT images. Finally, we used body weight to characterize patient size, method E, and compared this with the various other measurement methods. Methods were compared across the entire population as well as by subgroup based on body width. RESULTS: Concordance correlation (ρc) between each of the SSDE calculation methods (methods A-E) was greater than 0.92 across the entire population, although the range was wider when analyzed by subgroup (0.42-0.99). When we compared each SSDE measurement method with CTDIvol, there was poor correlation, ρc<0.77, with percentage differences between 20.8% and 51.0%. CONCLUSION: Automated computer algorithms are accurate and efficient in the calculation of SSDE. Manual methods based on patient thickness provide acceptable dose estimates for pediatric patients <30 cm in body width. Body weight provides a quick and practical method to identify conversion factors that can be used to estimate SSDE with reasonable accuracy in pediatric patients with body width ≥20 cm.

The association among prematurity, cochlear hyperintensity, and hearing loss.

Background Prematurity is a major risk factor for neonatal hearing loss. Recent advancements in magnetic resonance imaging (MRI) have made it possible to evaluate structural details of the membranous labyrinths in premature infants that have heretofore been inaccessible. Objective We compared the prevalence of abnormal cochlear signal intensity in premature and term neonates and evaluated for a potential link with hearing loss. Materials and methods We retrospectively reviewed 148 consecutive MR exams performed in premature (< 37 weeks' gestation) and term neonates performed over a 30-month period. Cochlear signal alteration was evaluated on three-dimensional T1-weighted imaging (T1WI) sequences. Each patient's electronic medical record was reviewed to document demographics, symptomatology, physical exam findings, and potential medical variables that could contribute to cochlear signal alteration. Results Cochlear hyperintensity on T1WI was present in 6.8% patients ( n = 10) overall, but was much more common in preterm than term patients (12.2% (9 of 74) vs. 1.4% (1 of 74), respectively; p value < 0.05; Fisher's exact test). Overall, 14.9% ( n = 15) of the patients with hearing test results failed the screening Auditory Brainstem Response exam. However, failure was much more common among patients with cochlear hyperintensity on T1W1 than those with normal findings (56% (5 of 9) vs. 11% (10 of 92), respectively; p value < 0.01; Fisher's exact test). Conclusion Cochlear hyperintensity on T1WI is more common in preterm than term neonates, and potentially associated with hearing loss. Cochleae should be closely scrutinized in all premature infants; signal alterations should prompt further diagnostic inquiry and possible early otolaryngology referral.

Successful Dose Reduction Using Reduced Tube Voltage With Hybrid Iterative Reconstruction in Pediatric Abdominal CT.

OBJECTIVE: The purpose of this article is to assess radiation dose reduction, image quality, and diagnostic confidence using low tube voltage in combination with hybrid iterative reconstruction in contrast-enhanced pediatric abdominal CT. MATERIALS AND METHODS: CT examinations of 133 patients (median age, 10 years) were performed at sequentially reduced doses. The first group (group 1) was scanned using dimension-based protocols at 120 kV for all patient sizes. The optimized group (group 5) was scanned at 80 kV for less than 18 cm in the lateral dimension and 100 kV in the 19-30 cm lateral dimension. CT examinations reconstructed with filtered back projection (FBP) and four levels of hybrid iterative reconstruction were reviewed by four blinded readers for subjective image quality and diagnostic confidence. Objective noise, volume CT dose index (CTDIvol), and size-specific dose estimate (SSDE) were recorded. Data were analyzed using t tests, one and two-way ANOVA, and the intraclass correlation coefficient. RESULTS: Compared with group 1, the radiation dose was reduced for group 5 by 63% measured by SSDE (4.69 vs 10.00 mGy; p < 0.001). Subjective image noise was increased for FBP images (p < 0.001) but not was statistically significantly different for all levels of hybrid iterative reconstruction; artifacts were reduced and visibility of small structures was improved (both p < 0.001). Diagnostic confidence was improved for solid organ injury and metastatic disease (both p < 0.001) and was not statistically significantly different for appendicitis (p = 0.306). CONCLUSION: Use of hybrid iterative reconstruction with low-tube-voltage protocols enables substantial radiation dose reduction for pediatric abdominal CT with equivalent to improved subjective image quality and diagnostic confidence.