Parameters Associated With Endothelial Cell Density Variability After Descemet Membrane Endothelial Keratoplasty.

PURPOSE: To evaluate which parameters may affect endothelial cell loss after Descemet membrane endothelial keratoplasty (DMEK) by comparing eyes in the low vs high quartile of endothelial cell loss over a follow-up period of 4 years. DESIGN: Retrospective cohort study. METHODS: Donor endothelial cell density (ECD) decline was evaluated for 351 eyes of 275 patients up to 4 years after DMEK for Fuchs endothelial corneal dystrophy (FECD). Eyes with a postoperative endothelial cell loss in the lower quartile at all available follow-up moments were assigned to Group 1 (n = 51) and those in the upper quartile to Group 2 (n = 42). Multinomial regression was used to assess which covariates were related to greater ECD decline. RESULTS: Mean endothelial cell loss as compared to preoperative donor ECD for the entire study group was 33 (±16)%, 36 (±17)%, and 52 (±18)% at 1, 6, and 48 months postoperatively. Endothelial cell loss of Group 1 was 12 (±7)%, 13 (±6)%, and 26 (±8)% at, respectively, 1, 6, and 48 months postoperatively, and 59 (±10)%, 64 (±9)%, and 75 (±5)% in Group 2. Partial graft detachment, donor death cause cardiovascular/stroke (vs cancer), postoperative complications other than graft detachment, and severity of preoperative FECD (all P < .01) showed the strongest relation with greater ECD decline. CONCLUSIONS: DMEK eyes with a completely attached graft and operated in an early stage of FECD may show the lowest endothelial cell loss postoperatively.

Characteristics of Rib Fractures in Child Abuse-The Role of Low-Dose Chest Computed Tomography.

OBJECTIVES: Our aim is to describe the radiologic characteristics of rib fractures in clinically diagnosed cases of child abuse and suggest a complementary imaging for radiographically occult injuries in highly suspicious cases of child abuse. METHODS: Retrospective analysis of initial and follow-up skeletal surveys and computed tomography (CT) scans of 16 patients younger than 12 months were reviewed after obtaining approval from our institutional review board. The number, location, displacement, and age of the rib fractures were recorded. RESULTS: Out of a total 105 rib fractures, 84% (87/105) were detected on the initial skeletal survey. Seventeen percent (18/105) were seen only after follow-up imaging, more than half of which (11/18) were detected on a subsequent CT. Majority of the fractures were posterior (43%) and anterior (30%) in location. An overwhelming majority (96%) of the fractures are nondisplaced. CONCLUSIONS: Seventeen percent of rib fractures analyzed in the study were not documented on the initial skeletal survey. Majority of fractures are nondisplaced and located posteriorly or anteriorly, areas that are often difficult to assess especially in the acute stage. The CT scan is more sensitive in evaluating these types of fractures. Low-dose chest CT can be an important imaging modality for suspicious cases of child abuse when initial radiographic findings are inconclusive.

A reminder of peristalsis as a useful tool in the prenatal differential diagnosis of abdominal cystic masses.

With routine antenatal ultrasound and recent advances in ultrasound technology, fetal intraabdominal cystic masses are recognized more often and are better characterized than in the past. They may be classified as solid and cystic, and may originate from multiple structures. When considering the extensive differential diagnosis of cystic masses, the observation of peristalsis narrows the possibilities to the gastrointestinal tract. To find this feature on ultrasound, the examiner must expressly think and look for it, otherwise it may be missed. Our case report illustrates one of those cases.

Effect of Abdominal Ultrasound on Clinical Care, Outcomes, and Resource Use Among Children With Blunt Torso Trauma: A Randomized Clinical Trial.

Importance: The utility of the focused assessment with sonography for trauma (FAST) examination in children is unknown. Objective: To determine if the FAST examination during initial evaluation of injured children improves clinical care. Design, Setting, and Participants: A randomized clinical trial (April 2012-May 2015) that involved 975 hemodynamically stable children and adolescents younger than 18 years treated for blunt torso trauma at the University of California, Davis Medical Center, a level I trauma center. Interventions: Patients were randomly assigned to a standard trauma evaluation with the FAST examination by the treating ED physician or a standard trauma evaluation alone. Main Outcomes and Measures: Coprimary outcomes were rate of abdominal computed tomographic (CT) scans in the ED, missed intra-abdominal injuries, ED length of stay, and hospital charges. Results: Among the 925 patients who were randomized (mean [SD] age, 9.7 [5.3] years; 575 males [62%]), all completed the study. A total of 50 patients (5.4%, 95% CI, 4.0% to 7.1%) were diagnosed with intra-abdominal injuries, including 40 (80%; 95% CI, 66% to 90%) who had intraperitoneal fluid found on an abdominal CT scan, and 9 patients (0.97%; 95% CI, 0.44% to 1.8%) underwent laparotomy. The proportion of patients with abdominal CT scans was 241 of 460 (52.4%) in the FAST group and 254 of 465 (54.6%) in the standard care-only group (difference, -2.2%; 95% CI, -8.7% to 4.2%). One case of missed intra-abdominal injury occurred in a patient in the FAST group and none in the control group (difference, 0.2%; 95% CI, -0.6% to 1.2%). The mean ED length of stay was 6.03 hours in the FAST group and 6.07 hours in the standard care-only group (difference, -0.04 hours; 95% CI, -0.47 to 0.40 hours). Median hospital charges were $46 415 in the FAST group and $47 759 in the standard care-only group (difference, -$1180; 95% CI, -$6651 to $4291). Conclusions and Relevance: Among hemodynamically stable children treated in an ED following blunt torso trauma, the use of FAST compared with standard care only did not improve clinical care, including use of resources; ED length of stay; missed intra-abdominal injuries; or hospital charges. These findings do not support the routine use of FAST in this setting. Trial Registration: clinicaltrials.gov Identifier: NCT01540318.

ACR Appropriateness Criteria® Suspected Physical Abuse-Child.

The youngest children, particularly in the first year of life, are the most vulnerable to physical abuse. Skeletal survey is the universal screening examination in children 24 months of age and younger. Fractures occur in over half of abused children. Rib fractures may be the only abnormality in about 30%. A repeat limited skeletal survey after 2 weeks can detect additional fractures and can provide fracture dating information. The type and extent of additional imaging for pediatric patients being evaluated for suspected physical abuse depends on the age of the child, the presence of neurologic signs and symptoms, evidence of thoracic or abdominopelvic injuries, and social considerations. Unenhanced CT of the head is the initial study for suspected intracranial injury. Clinically occult abusive head trauma can occur, especially in young infants. Therefore, head CT should be performed in selected neurologically asymptomatic physical abuse patients. Contrast-enhanced CT of the abdomen/pelvis is utilized for suspected intra-abdominal or pelvic injury. Particular attention should be paid to discrepancies between the patterns of injury and the reported clinical history. Making the diagnosis of child abuse also requires differentiation from anatomical and developmental variants and possible underlying metabolic and genetic conditions. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Urinary Tract Infection-Child.

Urinary tract infection (UTI) is common in young children and may cause pyelonephritis and renal scarring. Long-term complications from renal scarring are low. The role of imaging is to evaluate for underlying urologic abnormalities and guide treatment. In neonates there is increased risk for underlying urologic abnormalities. Evaluation for vesicoureteral reflux (VUR) may be appropriate especially in boys because of higher prevalence of VUR and to exclude posterior urethral valve. In children older than 2 months with first episode of uncomplicated UTI, there is no clear benefit of prophylactic antibiotic. Ultrasound is the only study that is usually appropriate. After the age of 6 years, UTIs are infrequent. There is no need for routine imaging as VUR is less common. In children with recurrent or complicated UTI, in addition to ultrasound, imaging of VUR is usually appropriate. Renal cortical scintigraphy may be appropriate in children with VUR, as renal scarring may support surgical intervention. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Regional Brain Water Content and Distribution During Diabetic Ketoacidosis.

OBJECTIVE: To characterize regional differences in brain water distribution and content during diabetic ketoacidosis (DKA) in children and determine whether these differences correlate with regional vascular supply. STUDY DESIGN: We compared changes in brain water distribution and water content in different brain regions during DKA by analyzing magnetic resonance diffusion weighted imaging data collected during DKA and after recovery in 45 children (<18 years of age). We measured the apparent diffusion coefficient (ADC) of water in the frontal and occipital cortex, basal ganglia, thalamus, hippocampus, and medulla. Brain water content was also measured in a subset of patients. RESULTS: ADC values were elevated (suggesting vasogenic cerebral edema) in the frontal cortex, basal ganglia, thalamus, and hippocampus during DKA. In contrast, ADC values in the medulla and the occipital cortex were not increased during DKA, and ADC changes in the medulla tended to be negatively correlated with other regions. Regions supplied by the anterior/middle cerebral artery circulation had greater elevations in both ADC and brain water content during DKA compared with regions supplied by the posterior cerebral artery circulation. CONCLUSIONS: ADC changes during DKA in the brainstem contrast with those of other brain regions, and changes in both ADC and brain water content during DKA vary according to regional vascular supply. These data suggest that brainstem blood flow might possibly be reduced during DKA concurrent with hyperemia in other brain regions.

ACR Appropriateness Criteria Fever Without Source or Unknown Origin-Child.

The cause of fever in a child can often be determined from history, physical examination, and laboratory tests; infections account for the majority of cases. Yet in 20%, no apparent cause can be found, designated as fever without source (FWS). The yield of chest radiography in children with FWS is low, and it is usually not appropriate. However, in children with respiratory signs, high fever (>39°C), or marked leukocytosis (≥20,000/mm(3)), chest radiography is usually appropriate, as it has a higher yield in detecting clinically occult pneumonia. In newborns with FWS, there is higher risk for serious bacterial infection, and the routine use of chest radiography is controversial. In children with neutropenia, fever is a major concern. In some clinical circumstances, such as after hematopoietic stem cell transplantation, chest CT scan may be appropriate even if the results of chest radiography are negative or nonspecific, as it has higher sensitivity and can demonstrate specific findings (such as lung nodule and "halo sign") that can guide management. In a child with prolonged fever of unknown origin despite extensive medical workup (fever of unknown origin), diagnosis is usually dependent on clinical and laboratory studies, and imaging tests have low yield. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Clinical Presentations and Outcomes of Children With Basilar Skull Fractures After Blunt Head Trauma.

STUDY OBJECTIVE: We describe presentations and outcomes of children with basilar skull fractures in the emergency department (ED) after blunt head trauma. METHODS: This was a secondary analysis of an observational cohort of children with blunt head trauma. Basilar skull fracture was defined as physical examination signs of basilar skull fracture without basilar skull fracture on computed tomography (CT), or basilar skull fracture on CT regardless of physical examination signs of basilar skull fracture. Other definitions included isolated basilar skull fracture (physical examination signs of basilar skull fracture or basilar skull fracture on CT with no other intracranial injuries on CT) and acute adverse outcomes (death, neurosurgery, intubation for >24 hours, and hospitalization for ≥2 nights with intracranial injury on CT). RESULTS: Of 42,958 patients, 558 (1.3%) had physical examination signs of basilar skull fracture, basilar skull fractures on CT, or both. Of the 525 (94.1%) CT-imaged patients, 162 (30.9%) had basilar skull fracture on CT alone, and 104 (19.8%) had both physical examination signs of basilar skull fracture and basilar skull fracture on CT; 269 patients (51.2%) had intracranial injuries other than basilar skull fracture on CT. Of the 363 (91.7%) CT-imaged patients with physical examination signs of basilar skull fracture, 104 (28.7%) had basilar skull fracture on CT. Of 266 patients with basilar skull fracture on CT, 104 (39.1%) also had physical examination signs of basilar skull fracture. Of the 256 CT-imaged patients who had isolated basilar skull fracture, none had acute adverse outcomes (0%; 95% confidence interval 0% to 1.4%), including none (0%; 95% confidence interval 0% to 6.1%) of 59 with isolated basilar skull fractures on CT. CONCLUSION: Approximately 1% of children with blunt head trauma have physical examination signs of basilar skull fracture or basilar skull fracture on CT. The latter increases the risk of acute adverse outcomes more than physical examination signs of basilar skull fracture. A CT scan is needed to adequately stratify the risk of acute adverse outcomes for these children. Children with isolated basilar skull fractures are at low risk for acute adverse outcomes and, if neurologically normal after CT and observation, are candidates for ED discharge.

ACR Appropriateness Criteria Vomiting in Infants up to 3 Months of Age.

Vomiting is a commonly reported symptom in infants less than three months of age. There are a multitude of pathologies to consider, both within and outside the gastrointestinal tract. In addition to conducting a thorough history and physical examination, a clinician formulates a reasonable differential diagnosis by consideration of two main factors: the infant's age and the characterization of the vomit as bilious or nonbilious. In this endeavor, the clinician is able to determine if an imaging study is needed and, if so, the urgency of the request. A review of the appropriate imaging evaluation of vomiting infants in the newborn to three-month-old age group is provided by organizing the discussion around the following three clinical scenarios: bilious vomiting, intermittent nonbilious vomiting since birth, and new-onset bilious vomiting. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every three years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Follow-up barium study after a negative water-soluble contrast examination for suspected esophageal leak: is it necessary?

The purpose of this study was to determine the value of follow-up barium esophogram in diagnosing esophageal injury or leak if the initial water-soluble contrast examination of the esophagus is normal. An institutional review board (IRB)-approved retrospective review of all pediatric patients less than 18 years old referred to the radiology department for evaluation of esophageal injury or leak was performed for a 9-year period from 2005 to 2014. The majority of patients had unexplained pneumomediastinum, chest trauma (gunshot or puncture wound), or foreign body ingestion as the reason for the referral. Forty-nine patients (age range 10 days to 17 years) underwent an initial water-soluble esophogram immediately followed by a barium esophogram. Forty-six studies were negative on both water-soluble contrast and barium studies. Two studies were both positive on the initial water-soluble contrast and subsequent barium studies. A single study showed the esophageal leak only in the water-soluble study, with the follow-up barium exam being normal. The result of this study indicates that a single-contrast water-soluble esophogram alone is sensitive in the diagnosis of esophageal injury or leak. It has a 100 % sensitivity and negative predictive value. A follow-up barium esophogram only increases the study time and radiation dose to the patient.

Use of Oral Contrast for Abdominal Computed Tomography in Children With Blunt Torso Trauma.

STUDY OBJECTIVE: We compare test characteristics of abdominal computed tomography (CT) with and without oral contrast for identifying intra-abdominal injuries. METHODS: This was a planned subanalysis of a prospective, multicenter study of children (<18 years) with blunt torso trauma. Children imaged in the emergency department with abdominal CT using intravenous contrast were eligible. Oral contrast use was based on the participating centers' guidelines and discretions. Clinical courses were followed to identify patients with intra-abdominal injuries. Abdominal CTs were considered positive for intra-abdominal injury if a specific intra-abdominal injury was identified and considered abnormal if any findings suggestive of intra-abdominal injury were identified on the CT. RESULTS: A total of 12,044 patients were enrolled, with 5,276 undergoing abdominal CT with intravenous contrast. Of the 4,987 CTs (95%) with documented use or nonuse of oral contrast, 1,010 (20%) were with and 3,977 (80%) were without oral contrast; 686 patients (14%) had intra-abdominal injuries, including 127 CTs (19%) with and 559 (81%) without oral contrast. The sensitivity in the detection of any intra-abdominal injury in the oral contrast versus no oral contrast groups was sensitivitycontrast 99.2% (95% confidence interval [CI] 95.7% to 100.0%) versus sensitivityno contrast 97.7% (95% CI 96.1% to 98.8%), difference 1.5% (95% CI -0.4% to 3.5%). The specificity of the oral contrast versus no oral contrast groups was specificitycontrast 84.7% (95% CI 82.2% to 87.0%) versus specificityno contrast 80.8% (95% CI 79.4% to 82.1%), difference 4.0% (95% CI 1.3% to 6.7%). CONCLUSION: Oral contrast is still used in a substantial portion of children undergoing abdominal CT after blunt torso trauma. With the exception of a slightly better specificity, test characteristics for detecting intra-abdominal injury were similar between CT with and without oral contrast.

Isolated linear skull fractures in children with blunt head trauma.

BACKGROUND AND OBJECTIVE: Children and adolescents with minor blunt head trauma and isolated skull fractures are often admitted to the hospital. The objective of this study was to describe the injury circumstances and frequency of clinically important neurologic complications among children with minor blunt head trauma and isolated linear skull fractures. METHODS: This study was a planned secondary analysis of a large prospective cohort study in children <18 years old with blunt head trauma. Data were collected in 25 emergency departments. We analyzed patients with Glasgow Coma Scale scores of 14 or 15 and isolated linear skull fractures. We ascertained acute neurologic outcomes through clinical information collected during admission or via telephone or mail at least 1 week after the emergency department visit. RESULTS: In the parent study, we enrolled 43,904 children (11,035 [25%] <2 years old). Of those with imaging studies, 350 had isolated linear skull fractures. Falls were the most common injury mechanism, accounting for 70% (81% for ages <2 years old). Of 201 hospitalized children, 42 had computed tomography or MRI repeated; 5 had new findings but none required neurosurgical intervention. Of 149 patients discharged from the hospital, 20 had repeated imaging, and none had new findings. CONCLUSIONS: Children with minor blunt head trauma and isolated linear skull fractures are at very low risk of evolving other traumatic findings noted in subsequent imaging studies or requiring neurosurgical intervention. Hospital admission for neurologically normal children with isolated linear skull fractures after minor blunt head trauma for monitoring is typically unnecessary.

Malignant renal tumors in children.

Renal malignancies are common in children. While the majority of malignant renal masses are secondary to Wilms tumor, it can be challenging to distinguish from more aggressive renal masses. For suspicious renal lesions, it is crucial to ensure prompt diagnosis in order to select the appropriate surgical procedure and treatment. This review article will discuss the common differential diagnosis that can be encountered when evaluating a suspicious renal mass in the pediatric population. This includes clear cell sarcoma of the kidney, malignant rhabdoid tumor, renal medullary carcinoma and lymphoma.

Current methods for reducing intussusception: survey results.

BACKGROUND: Intussusception is a common pediatric abdominal emergency, treated with image-guided reduction. Available techniques include fluoroscopic and ultrasonographic monitoring of liquid and air. OBJECTIVE: The purpose of this study was to determine current practices and establish trends by comparing our findings with reports of previous surveys. MATERIALS AND METHODS: This study is based on an e-mail survey sent to all 1,538 members of the Society for Pediatric Radiology. It included questions about demographics, presence of parents/surgeon during procedure, patient selection/preparation, use of sedation, preferred methods of reduction and technical details, approach to unsuccessful reduction, and self-reported incidence of success/perforation. RESULTS: The 456 respondents (30%) reported attempting 3,834 reductions in the preceding 12 months. Of these, 96% use fluoroscopy and 4% use US guidance for reduction; 78% use air, 20% prefer fluid; 75% require intravenous access; 63% expect a surgeon to be present in hospital; 93% do not sedate. Although inflating a rectal balloon is controversial, 39% do so, and 50% employ a pressure-release valve. Seventy-two percent attempt reductions three times in the same position. In case of unsuccessful reductions, 64% wait and re-attempt later, 19% apply manual pressure, and 15% try again in left decubitus position. About 20% reattempt reduction after waiting 2 h or more. CONCLUSION: By providing a better understanding of both trends in and diversity of current practice, we hope to increase the confidence with which the individual practitioner will approach each case.

ACR Appropriateness Criteria head trauma--child.

Head trauma is a frequent indication for cranial imaging in children. CT is considered the first line of study for suspected intracranial injury because of its wide availability and rapid detection of acute hemorrhage. However, the majority of childhood head injuries occur without neurologic complications, and particular consideration should be given to the greater risks of ionizing radiation in young patients in the decision to use CT for those with mild head trauma. MRI can detect traumatic complications without radiation, but often requires sedation in children, owing to the examination length and motion sensitivity, which limits rapid assessment and exposes the patient to potential anesthesia risks. MRI may be helpful in patients with suspected nonaccidental trauma, with which axonal shear injury and ischemia are more common and documentation is critical, as well as in those whose clinical status is discordant with CT findings. Advanced techniques, such as diffusion tensor imaging, may identify changes occult by standard imaging, but data are currently insufficient to support routine clinical use. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Effectiveness of the head CT choice decision aid in parents of children with minor head trauma: study protocol for a multicenter randomized trial.

BACKGROUND: Blunt head trauma is a common cause of death and disability in children worldwide. Cranial computed tomography (CT), the reference standard for the diagnosis of traumatic brain injury (TBI), exposes children to ionizing radiation which has been linked to the development of brain tumors, leukemia, and other cancers. We describe the methods used to develop and test the effectiveness of a decision aid to facilitate shared decision-making with parents regarding whether to obtain a head CT scan or to further observe their child at home. METHODS/DESIGN: This is a protocol for a multicenter clinician-level parallel randomized trial to compare an intervention group receiving a decision aid, 'Head CT Choice', to a control group receiving usual care. The trial will be conducted at five diverse emergency departments (EDs) in Minnesota and California. Clinicians will be randomized to decision aid or usual care. Parents visiting the ED with children who are less than 18-years-old, have experienced blunt head trauma within 24 hours, and have one or two risk factors for clinically-important TBI (ciTBI) from the Pediatric Emergency Care Applied Research Network head injury clinical prediction rules will be eligible for enrollment. We will measure the effect of Head CT Choice on: (1) parent knowledge regarding their child's risk of ciTBI, the available diagnostic options, and the risks of radiation exposure associated with a cranial CT scan (primary outcome); (2) parent engagement in the decision-making process; (3) the degree of conflict parents experience related to feeling uninformed; (4) patient and clinician satisfaction with the decision made; (5) the rate of ciTBI at seven days; (6) the proportion of patients in whom a cranial CT scan is obtained; and (7) seven-day healthcare utilization. To capture these outcomes, we will administer parent and clinician surveys immediately after each clinical encounter, obtain video recordings of parent-clinician discussions, administer parent healthcare utilization diaries, analyze hospital billing records, review the electronic medical record, and conduct telephone follow-up. DISCUSSION: This multicenter trial will robustly assess the effectiveness of a decision aid on patient-centered outcomes, safety, and healthcare utilization in parents of children with minor head trauma in five diverse EDs. TRIAL REGISTRATION: ClinicalTrials.gov registration number: NCT02063087. Registration date February 13, 2014.

Occult pneumothoraces in children with blunt torso trauma.

OBJECTIVES: Plain chest x-ray (CXR) is often the initial screening test to identify pneumothoraces in trauma patients. Computed tomography (CT) scans can identify pneumothoraces not seen on CXR ("occult pneumothoraces"), but the clinical importance of these radiographically occult pneumothoraces in children is not well understood. The objectives of this study were to determine the proportion of occult pneumothoraces in injured children and the rate of treatment with tube thoracostomy among these children. METHODS: This was a planned substudy from a large prospective multicenter observational cohort study of children younger than 18 years old evaluated in emergency departments (EDs) in the Pediatric Emergency Care Applied Research Network (PECARN) for blunt torso trauma from May 2007 to January 2010. Children with CXRs as part of their trauma evaluations were included for analysis. The faculty radiologist interpretations of the CXRs and any subsequent imaging studies, including CT scans, were reviewed for the absence or presence of pneumothoraces. An "occult pneumothorax" was defined as a pneumothorax that was not identified on CXR, but was subsequently demonstrated on cervical, chest, or abdominal CT scan. Rates of pneumothoraces and placement of tube thoracostomies and rate differences with 95% confidence intervals (CIs) were calculated. RESULTS: Of 12,044 enrolled in the parent study, 8,020 (67%) children (median age=11.3 years, interquartile range [IQR]=5.3 to 15.2 years) underwent CXRs in the ED, and these children make up the study population. Among these children, 4,276 had abdominal CT scans performed within 24 hours. A total of 372 of 8,020 children (4.6%; 95% CI=4.2% to 5.1%) had pneumothoraces identified by CXR and/or CT. The CXRs visualized pneumothoraces in 148 patients (1.8%; 95% CI=1.6% to 2.2%), including one false-positive pneumothorax, which was identified on CXR, but was not demonstrated on CT. Occult pneumothoraces were present in 224 of 372 (60.2%; 95% CI=55.0% to 65.2%) children with pneumothoraces. Tube thoracostomies were performed in 85 of 148 (57.4%; 95% CI=49.0% to 65.5%) children with pneumothoraces on CXR and in 35 of 224 (15.6%; 95% CI=11.1% to 21.1%) children with occult pneumothoraces (rate difference=-41.8%; 95% CI=-50.8 to -32.3%). CONCLUSIONS: In pediatric patients with blunt torso trauma, pneumothoraces are uncommon, and most are not identified on the ED CXR. Nearly half of pneumothoraces, and most occult pneumothoraces, are managed without tube thoracostomy. Observation, including in children requiring endotracheal intubation, should be strongly considered during the initial management of children with occult pneumothoraces.

Dose is not always what it seems: where very misleading values can result from volume CT dose index and dose length product.

PURPOSE: The volume CT dose index (CTDIvol) and the dose-length product, commonly reported for examinations performed on clinical CT scanners, should not be used as surrogates for patient dose. This is because significant under or overestimates of these actual values can occur when there is a mismatch between the actual body size of the patient and the 16 cm or 32 cm diameter CTDIvol phantoms. This mismatch can be exacerbated in pediatric body examinations because of the fact that some manufacturers use the large diameter phantom while other manufacturers use the small diameter phantom as the CTDIvol reference phantom. METHOD: A clinical example is described for a pediatric patient with a 4-fold difference in CTDIvol between a presurgical CT examination and a postsurgical CT examination, even though the actual dose absorbed by the patient was about the same. Using methods published by the American Association of Physicists in Medicine, we calculated the size-specific dose estimate (SSDE), and compared the estimated measurement of dose using the SSDE with the CTDIvol. RESULTS: Using SSDE significantly reduced the discrepancy in radiation dose estimates of CTDIvol in the clinical study, and allowed dose estimate comparisons between scanners to be more meaningful. CONCLUSIONS: Radiation dose estimates are more accurate when using the SSDE metric in lieu of the CTDIvol metric for reporting and comparing patient dose indices.