Optimization of hybrid iterative reconstruction level in pediatric body CT.

OBJECTIVE: The objective of our study was to attempt to optimize the level of hybrid iterative reconstruction (HIR) in pediatric body CT. MATERIALS AND METHODS: One hundred consecutive chest or abdominal CT examinations were selected. For each examination, six series were obtained: one filtered back projection (FBP) and five HIR series (iDose(4)) levels 2-6. Two pediatric radiologists, blinded to noise measurements, independently chose the optimal HIR level and then rated series quality. We measured CT number (mean in Hounsfield units) and noise (SD in Hounsfield units) changes by placing regions of interest in the liver, muscles, subcutaneous fat, and aorta. A mixed-model analysis-of-variance test was used to analyze correlation of noise reduction with the optimal HIR level compared with baseline FBP noise. RESULTS: One hundred CT examinations were performed of 88 patients (52 females and 36 males) with a mean age of 8.5 years (range, 19 days-18 years); 12 patients had both chest and abdominal CT studies. Radiologists agreed to within one level of HIR in 92 of 100 studies. The mean quality rating was significantly higher for HIR than FBP (3.6 vs 3.3, respectively; p < 0.01). HIR caused minimal (0-0.2%) change in CT numbers. Noise reduction varied among structures and patients. Liver noise reduction positively correlated with baseline noise when the optimal HIR level was used (p < 0.01). HIR levels were significantly correlated with body weight and effective diameter of the upper abdomen (p < 0.01). CONCLUSION: HIR, such as iDose(4), improves the quality of body CT scans of pediatric patients by decreasing noise; HIR level 3 or 4 is optimal for most studies. The optimal HIR level was less effective in reducing liver noise in children with lower baseline noise.

Comparing bedside methods of determining placement of gastric tubes in children.

PURPOSE: The purpose of this study was to compare the accuracy and predictive validity of pH, bilirubin, and CO2 in identifying gastric tube placement errors in children. DESIGN AND METHODS: After the tube was inserted into 276 children, the CO2 monitor reading was obtained. Fluid was then aspirated to test pH and bilirubin. RESULTS: Lack of ability to obtain tube aspirate was the best predictor of NG/OG placement errors with a sensitivity of 34.9% and a positive predictive value of 66.7%. Measuring pH, bilirubin, and CO2 of tube aspirate was less helpful. PRACTICE IMPLICATIONS: Healthcare providers should suspect NG/OG tube misplacement when no fluid is aspirated.

Removal of comfort pads underneath babies: a method of reducing radiation exposure to neonates.

RATIONALE AND OBJECTIVES: The recent increasing utilization of imaging has increased the population exposure to ionizing radiation. With increasing knowledge of the potential harm of radiation exposure, efforts should be made to minimize patient radiation whenever possible, especially in young children. The purpose of this study was to use the exposure index (EI) standard to assess the potential for reducing radiation dose to babies by removing a soft comfort pad, often placed underneath the baby. The pad is located between the baby and the image detector plate. As such it absorbs x-rays that have already passed through the baby but have not yet reached the imaging detector plate. MATERIALS AND METHODS: Using a thoracic infant phantom and fixed exposure factors, we measured the percentage of the radiation exiting a neonatal chest phantom that was absorbed/attenuated by the comfort pad, before it hit the detector to create the image. We studied comfort pads of 4 different thicknesses, ranging from 0.5″ to 8″. RESULTS: Radiation beam attenuation, ranging from 12% to 72.1%, was found with all comfort pads, with increased x-ray beam attenuation occurring with increasing pad thickness. CONCLUSIONS: The study shows that comfort pads cause a high attenuation of the radiation beam, after it exits the chest phantom. As such, removal of the pads prior to radiographic exposure of babies is a method of potentially reducing patient radiation exposure in the newborn nursery.

Image gently campaign back to basics initiative: ten steps to help manage radiation dose in pediatric digital radiography.

OBJECTIVE: The purpose of this review is to summarize 10 steps a practice can take to manage radiation exposure in pediatric digital radiography. CONCLUSION: The Image Gently campaign raises awareness of opportunities for lowering radiation dose while maintaining diagnostic quality of images of children. The newest initiative in the campaign, Back to Basics, addresses methods for standardizing the approach to pediatric digital radiography, highlighting challenges related to the technology in imaging of patients of widely varying body sizes.

Tracheoesophageal fistula following button battery ingestion: successful non-operative management.

The incidence of devastating complications from button battery ingestions is increasing. Battery impactions may result in erosive esophagitis, tracheoesophageal fistula (TEF), esophageal strictures, spondylodiscitis, vocal cord paralysis due to paralysis of recurrent laryngeal nerve(s), and aortoesophageal fistulas with significant morbidity and mortality. We present a case of a 15 month old boy who developed an acquired TEF secondary to ingestion of a 20mm button battery lodged at the level of the carina. The clinical course and imaging findings are reviewed. Serial limited CT imaging with 3-D reconstruction was helpful in noninvasive assessment of healing and clinical decision making. Of special interest are the negative initial esophagram and the healing of the fistula without the need for surgical intervention.

Imatinib mesylate for plexiform neurofibromas in patients with neurofibromatosis type 1: a phase 2 trial.

BACKGROUND: Plexiform neurofibromas are slow-growing chemoradiotherapy-resistant tumours arising in patients with neurofibromatosis type 1 (NF1). Currently, there are no viable therapeutic options for patients with plexiform neurofibromas that cannot be surgically removed because of their proximity to vital body structures. We undertook an open-label phase 2 trial to test whether treatment with imatinib mesylate can decrease the volume burden of clinically significant plexiform neurofibromas in patients with NF1. METHODS: Eligible patients had to be aged 3-65 years, and to have NF1 and a clinically significant plexiform neurofibroma. Patients were treated with daily oral imatinib mesylate at 220 mg/m(2) twice a day for children and 400 mg twice a day for adults for 6 months. The primary endpoint was a 20% or more reduction in plexiform size by sequential volumetric MRI imaging. Clinical data were analysed on an intention-to-treat basis; a secondary analysis was also done for those patients able to take imatinib mesylate for 6 months. This trial is registered with ClinicalTrials.gov, number NCT01673009. FINDINGS: Six of 36 patients (17%, 95% CI 6-33), enrolled on an intention-to-treat basis, had an objective response to imatinib mesylate, with a 20% or more decrease in tumour volume. Of the 23 patients who received imatinib mesylate for at least 6 months, six (26%, 95% CI 10-48) had a 20% or more decrease in volume of one or more plexiform tumours. The most common adverse events were skin rash (five patients) and oedema with weight gain (six). More serious adverse events included reversible grade 3 neutropenia (two), grade 4 hyperglycaemia (one), and grade 4 increases in aminotransferase concentrations (one). INTERPRETATION: Imatinib mesylate could be used to treat plexiform neurofibromas in patients with NF1. A multi-institutional clinical trial is warranted to confirm these results. FUNDING: Novartis Pharmaceuticals, the Indiana University Simon Cancer Centre, and the Indiana University Herman B Wells Center for Pediatric Research.

Severe lateral tibial bowing with short stature in two siblings--a provisionally novel syndrome.

In this report, we describe two siblings with short stature and severe lateral tibial bowing. In the younger sibling, the bowing was bilateral, while in the older sib, it was unilateral. However, both showed bilateral abnormalities of the distal tibial epiphyses and growth plates. Pseudoarthrosis of the left distal tibial metaphysis and subsequent spontaneous resolution of the abnormality occurred in the younger sibling. The fibulas of both children were of normal diameter and were straight, except for the distal ends. Surgery has almost completely corrected the lower leg bowing in both patients. The type of tibial bowing seen in these children can be associated with a number of syndromes, such as neurofibromatosis type I, Weismann-Netter syndrome, and a variety of environmental caused disorders, such as vitamin D deficient rickets. However, the severity of the bowing present in our patients and the absence of other clinical features differentiates this condition from those reported in the literature. We posit that the condition in the children presented here represents an as yet undescribed syndrome, which is likely to be of genetic origin.

Marrow signal changes observed in follow-up whole-body MRI studies in children and young adults with neurofibromatosis type 1 treated with imatinib mesylate (Gleevec) for plexiform neurofibromas.

BACKGROUND: We observed bone marrow signal changes (BMSC) in patients with plexiform neurofibromas after treatment with imatinib mesylate (Gleevec). OBJECTIVE: To evaluate the pattern and natural history of BMSC. MATERIALS AND METHODS: The data were obtained from a pilot study of imatinib mesylate in patients with plexiform neurofibromas. All patients underwent baseline and sequential whole-body STIR 1.5-T MRI after treatment. The bone marrow signal on MRI was evaluated for abnormalities, location and pattern, and any change on follow-up studies. RESULTS: The study group included 16 patients (8 males) with a median age of 14 years (range 4 to 25 years). The mean whole-body MRI follow-up duration was 1.9 years. Of the 16 patients, 14 (88%) developed BMSC. The signal change was asymmetrical in 9 of the 14 patients (64%). The appendicular skeleton was involved in all 14 patients and the axial skeleton in 3 patients (21%). BMSC was followed in 13 patients and decreased signal was seen in 9 patients (69%) after a mean duration of 1.3 years of treatment (range 0.6 to 2.9 years); no complications were observed. CONCLUSION: BMSC appeared in most patients with neurofibromatosis type 1 following treatment with imatinib mesylate. BMSC was unusually asymmetrical and involved the lower extremities. On follow-up, BMSC often showed a decrease without complications.