Should helical CT scanning of the thoracic cavity replace the conventional chest x-ray as a primary assessment tool in pediatric trauma? An efficacy and cost analysis

Thoracic Imaging in Pediatric Trauma: Are CTs Necessary?

OBJECTIVES

Imaging algorithms for assessment of thoracic trauma in pediatric patients remain controversial, attempting to balance radiation dose and its associated risk with the need for thorough assessment of patients' injuries. This study reviewed the value of chest radiography in detecting traumatic injuries, and the impact that computed tomography (CT) had on clinical management.

METHODS

A retrospective review of pediatric trauma patients undergoing chest radiography and thoracic CT over a 2-year period at a level 1 trauma center was performed. The incidence of various traumatic injuries was documented, with measures of sensitivity and specificity on radiography. Clinical notes were reviewed to identify any changes in care based on CT findings.

RESULTS

Eighty-one pediatric trauma patients underwent thoracic CT over a 2-year period, with 60 patients meeting the inclusion criteria. Radiographs identified 47 traumatic injuries out of 117 seen on the subsequent CT examinations for a sensitivity of 41% and specificity of 91%. Radiographs were most sensitive in detecting osseous injuries with a sensitivity of 54%. Additional CT findings changed management in 2 of 60 cases, or 3.3% of the time.

CONCLUSIONS

Use of thoracic CT in pediatric trauma patients identifies a significantly greater number of injuries compared with than radiography but significantly increases radiation dose while changing management in only a very small proportion of cases. Despite the relatively small sample size, the findings reflect 2 years of experience at a level 1 trauma center, and this study suggests that it may be reasonable to decrease the frequency of cross-sectional imaging.

Selective Computed Tomography (CT) Imaging is Superior to Liberal CT Imaging in the Hemodynamically Normal Pediatric Blunt Trauma Patient

BACKGROUND

The optimal imaging strategy in hemodynamically stable pediatric blunt trauma remains to be defined. The purpose of this study was to determine the differences between selective and liberal computed tomography (CT) strategy in a pediatric trauma population with respect to radiation exposure and outcomes.

METHODS

We performed a retrospective analysis of hemodynamically stable blunt pediatric trauma patients (≤16 y) who were admitted to a Level I trauma center between 2013-2016. Patients were stratified into selective and liberal imaging cohorts. Univariate and multivariate regression analyses were used to compare outcomes between the groups. Outcomes included radiation dose, hospital and ICU length of stay, complications and mortality.

RESULTS

Of the 485 patients included, 176 underwent liberal and 309 selective CT imaging. The liberal cohort were more likely to be severely injured (ISS>15: 34.1 versus 8.4%, P< 0.001). The odds of exposure to a radiation dose of >15 mSv were higher with liberal scanning in patients with both ISS > 15 (OR 2.78, 95% CI 1.76-5.19, P< 0.001) and ISS ≤ 15 (OR 3.41, 95% CI 2.19-8.44, P < 0.001). Adjusted outcomes regarding mortality, ICU length of stay, and complications were similar between the cohorts.

CONCLUSION

Selective CT imaging in hemodynamically stable blunt pediatric trauma patients was associated with reduced radiation exposure and similar outcomes when compared to a liberal CT strategy.

Chest x-ray vs. computed tomography of the chest in pediatric blunt trauma

INTRODUCTION

Chest x-ray (CXR) has been shown to be an effective detection tool for clinically significant trauma. We evaluated differences in findings between CXR and computed tomography of the chest (CCT), their impact on clinical management and the performance of the CXR.

METHODS

This retrospective study examined children (less than 18 years) who received a CXR and CCT between 2009 and 2015. We compared characteristics of children by conducting univariate analysis, reporting the proportion of additional diagnoses captured by CCT, and using it to evaluate the sensitivity and specificity of the CXR. Outcome variables were diagnoses made by CCT as well as the ensuing changes in the clinical management attributable to the diagnoses reported by the CCT and not observed by the CXR.

RESULTS

In 1235 children, CCT was associated with diagnosing higher proportions of contusion or atelectasis (60% vs 31%; p < .0001), pneumothorax (23% vs 9%; p < .0001), rib fracture (18% vs 7%; p < .0001), other fracture (20% vs 10%; p < .0001), diaphragm rupture (0.2% vs 0.1%; p = .002), and incidental findings (7% vs 2%; p < .0001) as compared to CXR. CCT findings changed the management of 107 children (8.7%) with 32 (2.6%) of the changes being surgical procedures. The overall sensitivity and specificity of the CXR were 57.9% (95% CI: 54.5-61.2) and 90.2% (95% CI: 86.8-93.1), respectively. The positive predictive value and negative predictive value were 93.1% and 48.6%, respectively.

CONCLUSION

CXR is a useful initial screening tool to evaluate pediatric trauma patients along with clinical presentation in the Emergency Department in children.

LEVEL OF EVIDENCE

Level III, diagnostic test.

Blunt traumatic scapular fractures are associated with great vessel injuries in children

BACKGROUND

Patients with stable blunt great vessel injury (GVI) can have poor outcomes if the injury is not identified early. With current pediatric trauma radiation reduction efforts, these injuries may be missed. As a known association between scapular fracture and GVI exists in adult blunt trauma patients, we examined whether that same association existed in pediatric blunt trauma patients.

METHODS

Bluntly injured patients younger than 18 years old were identified from 2012 to 2014 in the National Trauma Data Bank. Great vessel injury included all major thoracic vessels and carotid/jugular. Demographics of patients with and without scapular fracture were compared with descriptive statistics. The χ test was used to examine this association using SAS Version 9.4 (SAS Institute, Inc, Cary, NC).

RESULTS

We found a significant association between pediatric scapular fracture and GVI. Of 291,632 children identified, 1,960 had scapular fractures. Children with scapular fracture were 10 times more likely to have GVI (1.2%) compared to those without (0.12%, p < 0.0001). Most common GVI seen were carotid artery, thoracic aorta, and brachiocephalic or subclavian artery or vein. Children with both scapular fracture and GVI were most commonly injured by motor vehicles (57% collision, 26% struck).

CONCLUSIONS

Injured children with blunt scapular fracture have a 10-fold greater risk of having a GVI when compared to children without scapular fracture. Presence of blunt traumatic scapular fracture should have appropriate index of suspicion for a significant GVI in pediatric trauma patients.

LEVEL OF EVIDENCE

Epidemiologic and prognostic study, level III; Therapeutic, level IV.

Diagnostic Value of Ultrasound in Detecting Causes of Pediatric Chest X-Ray Opacity

OBJECTIVES

Computed tomography is considered as the diagnostic gold standard for following up the majority of pediatric chest X-ray (CXR) opacities. However, radiation, cost, and waiting times have led to search for diagnostic alternatives. This study was conducted to determine the diagnostic accuracy of the ultrasound (US) in detecting the causes of pediatric CXR opacities.

MATERIALS AND METHODS

This study was conducted on the pediatric patients with CXR opacity referring to Dr. Sheikh Hospital in Mashhad, Iran during 2016-2017. After undergoing the US exam, the patients were followed to obtain the final diagnosis based on reference standard (RF). The accuracy of the US was calculated in detection of thoracic lesions. P value <0.05 was considered to be significant.

RESULTS

The most common diagnostic cause of CXR opacity based on RF was pneumonia (n=46, 35-38%), thymus (n=37, 28-46%), bone and soft tissue mass (n=12, 9.23%), cystic lesions (n=11, 8.46%), and diaphragmatic lesions (n=10, 7.69%), as well as intrathoracic masses and empyema (n=7, 5.38%). In only four patients (3.07%), the final diagnosis based on RF was inconsistent with the US diagnosis. The diagnostic accuracy of the US was 100% in the diagnosis of bone and soft tissue masses, diaphragmatic lesions, empyema, and normal thymus, and the accuracy was 96.92% for pneumonia, and 99.23% for cystic lesions and intrathoracic masses.

CONCLUSION

Regarding the assessed diagnostic accuracy, the US can be a reliable diagnostic tool to differentiate the main cause of pediatric CXR opacity.

Chest radiographs versus CT for the detection of rib fractures in children (DRIFT): a diagnostic accuracy observational study

Background

Internationally, chest radiography is the standard investigation for identifying rib fractures in suspected physical abuse in infants. Several small observation studies in children have found that chest CT can provide greater accuracy than radiography for fracture detection, potentially aiding medicolegal proceedings in abuse cases; however, to our knowledge, this greater accuracy has not been comprehensively evaluated. We aimed to determine differences in rib fracture detection rates between post-mortem chest radiographs and chest CT images, using forensic autopsy as the reference standard.

Methods

In this retrospective diagnostic accuracy study, we searched the Great Ormond Street Hospital (London, UK) radiology information system for all children aged 0–16 years who had a post-mortem skeletal survey (ie, full-body radiography), CT, and full autopsy between Jan 1, 2012, and Jan 1, 2017, for a purpose of death investigation. Cases were excluded if the imaging was done for a reason other than a forensic investigation or if image quality was suboptimal. Radiologists were recruited as reporters on a voluntary basis via membership databases from international radiology and post-mortem imaging societies with no specific inclusion or exclusion criteria. Reporters were sent a set of chest radiographs on a password protected and encrypted USB flash drive or via a secure filesharing website and independently reported on the presence of rib fractures, fracture location, and the confidence level of their interpretation. They were masked to the clinical information of the images. 1 month later, the same reporters were sent CTs for the same cases in a random order and asked to report on the same features. The primary objective was to compare the accuracy of detection of rib fractures by use of post-mortem chest radiographs and CTs, with autopsy data as reference standard. Accuracy was assessed by comparison of diagnostic statistics, calculated using random-intercept multilevel logistic models with reporter and patient included as cross-classified random-effects.

Findings

25 cases of children (aged 1 month to 7 years), with 136 rib fractures at autopsy with paired post-mortem chest radiographs and CTs, were selected for analysis. 38 radiologists were recruited as reporters from 23 international centres; 12 (32%) were consultants, median experience of 14·5 years (range 6–27), and 26 (68%) were registrars, median experience of 4 years (range 2–9). Across all radiologists, three times as many rib fractures were correctly detected by use of chest CTs compared with chest radiography (sensitivity 44·9% [95% CI 31·7–58·9] vs 13·5% [8·1–21·5]; difference 31·4% [23·3–37·8; p<0·001]). Sensitivity for detection on the correct rib was higher by use of CT than by use of radiography (62·4% [95% CI 44·9–77·1] vs 23·1% [12·9–37·8]; difference 39·3% [31·9–42·2; p<0·001]), as was diagnosis of a patient with any rib fracture or fractures (81·5% [75·8–86·0] vs 64·7% [57·3–71·4]; difference 16·7% [11·5–22·2; p<0·001]). Radiologist confidence was higher when using CT images than radiographs (highest confidence rating given on 3317 [63·6%] of 5218 fractures for CT vs 1518 [46·6%] of 3303 on radiographs) and was a predictor for accurate fracture detection.

Interpretation

Chest CT provides greater accuracy than conventional chest radiography for post-mortem rib fracture detection, irrespective of radiologist experience or fracture location, although both methods detected a substantial number of false positives. The diagnostic accuracy of CT should be studied further in live children ideally in a multicentre trial to assess the applicability of our results.

Funding

Great Ormond Street Children's Charity, Medical Research Council, Royal College of Radiologists, Research Councils UK, National Institute for Health Research.

Thoracic injury rule out criteria and NEXUS chest in predicting the risk of traumatic intra-thoracic injuries: A diagnostic accuracy study

INTRODUCTION

This study aimed to compare the diagnostic accuracy of NEXUS chest and Thoracic Injury Rule out criteria (TIRC) models in predicting the risk of intra-thoracic injuries following blunt multiple trauma.

METHODS

In this diagnostic accuracy study, using the 2 mentioned models, blunt multiple trauma patients over the age of 15 years presenting to emergency department were screened regarding the presence of intra-thoracic injuries that are detectable via chest x-ray and screening performance characteristics of the models were compared.

RESULTS

In this study, 3118 patients with the mean (SD) age of 37.4 (16.9) years were studied (57.4% male). Based on TIRC and NEXUS chest, respectively, 1340 (43%) and 1417 (45.4%) patients were deemed in need of radiography performance. Sensitivity, specificity, and positive and negative predictive values of TIRC were 98.95%, 62.70%, 21.19% and 99.83%. These values were 98.61%, 59.94%, 19.97% and 99.76%, for NEXUS chest, respectively. Accuracy of TIRC and NEXUS chest models were 66.04 (95% CI: 64.34-67.70) and 63.50 (95% CI: 61.78-65.19), respectively.

CONCLUSION

TIRC and NEXUS chest models have proper and similar sensitivity in prediction of blunt traumatic intra-thoracic injuries that are detectable via chest x-ray. However, TIRC had a significantly higher specificity in this regard.

Factors Predicting Lung Contusions in Critically Ill Trauma Children: A Multivariate Analysis of 330 Cases

PURPOSE

The aim of the study was to identify factors predicting lung contusion in trauma children.

METHODS

Retrospective study conducted for a period of 8 years (January 01, 2005-December 31, 2012) in a medical surgical intensive care unit. All trauma patients younger than 15 years were included. Two groups were compared: those with lung contusions (C+ group) and those without lung contusions (C- group).

RESULTS

We included 330 patients. The mean (SD) age was 7.6 (4.3) years. Chest injury was diagnosed in 70 patients (21.2%). All our patients needed mechanical ventilation. Lung contusions were diagnosed in 43 patients (13% of all patients and 61.4% of patients with chest trauma). In multivariate analysis, independent factors predicting lung contusion were road traffic accident (odds ratio [OR], 3.2; 95% confidence interval [CI], 1.2-8.6; P = 0.019), increased Pediatric Risk of Mortality (PRISM) score (OR, 1.1; 95% CI, 1.1-1.2; P = 0.017), hepatic contusion (OR, 4.8; 95% CI, 1.3-17.1; P = 0.017), and pelvic ring fracture (OR, 3.5; 95% CI, 1.1-10.5; P = 0.026). Death occurred in 46 patients (13.9%). Intensive care unit mortality was significantly higher in the C+ group (OR, 2.5; 95% CI, 1.2-5.4; P = 0.021). However, mortality was not different between the 2 groups after adjusting for PRISM score (OR, 1.2; 95% CI, 0.5-2.9; P = 0.752) or after adjusting for Injury Severity Score (OR, 0.7; 95% CI, 0.3-2.1; P = 0.565).

CONCLUSIONS

Lung contusion is common in critically ill children with chest trauma. The diagnosis should be considered in patients with road traffic accident, increased PRISM score, hepatic contusion, and pelvic ring fracture.

Utilization of conventional radiography in a regional neonatal intensive care unit in Ireland

OBJECTIVE

To audit the demand and radiation exposure of conventional radiography in a regional neonatal intensive care unit (NICU) in Ireland.

METHODS

A retrospective study of radiographs performed on all admissions to the NICU in University Maternity Hospital Limerick (UMHL) over 2 years.

RESULTS

A total of 1405 radiographs were performed on 506 infants. 153.5 radiographs per 1000 live births was the observed demand and 44% of radiographs were done out of hours. 47% of all radiographs were performed on infants <1500 g. Median number of radiographs per infant was one (IQR 1-2; range 1-39). Significant negative correlation was observed between number of radiographs and gestational age. Mean lung radiation doses estimated using published values for normal weight (>2500 g), very low birth weight (VLBW), and extremely low birth weight (ELBW) infants based on the median number of chest X-rays were 31.7 µGym, 84.66 and 232.75 µGy, respectively.

CONCLUSIONS

Conventional radiography remains a key diagnostic tool in neonatology particularly in VLBW and ELBW infants and is invaluable in supporting timely clinical decision making. Clinicians should be aware of the cost and potential hazards of neonatal radiography and is recommend that the cumulative radiation exposure among the ELBW and VLBW infants is monitored. Increasing awareness and standardisation of point-of-care ultrasonography could decrease the reliance on conventional radiography in neonatal units.

Diagnostic Imaging in pediatric thoracic trauma

Thoracic trauma accounts for approximately 14% of blunt force traumatic deaths, second only to head injuries. Chest trauma can be blunt (90% of cases) or penetrating. In young patients, between 60 and 80% of chest injuries result from blunt trauma, with over half as a consequence of impact with motor vehicles, whereas in adolescents and adults, penetrating trauma has a statistically more prominent role. Pulmonary contusions and rib fractures are the most frequent injuries occurring. Chest X-ray is the first imaging modality of choice to identify patients presenting with life-threatening conditions (i.e., tension pneumothorax, huge hemothorax, and mediastinal hematoma) and those who require a CT examination. Multi-Slice Computed Tomography is the gold standard to evaluate chest injuries. In fact, the high spatial resolution, along with multiplanar reformation and three-dimensional (3D) reconstructions, makes MDCT the ideal imaging method to recognize several chest injuries such as rib fractures, pneumothorax, hemothorax, lung contusions and lacerations, diaphragmatic rupture, and aortic injuries. Nevertheless, when imaging a young patient, one should always keep into account the ALARA concept, to balance an appropriate and low-dose technique with imaging quality and to reduce the amount of ionizing radiation exposure. According to this concept, in the recent years, the current trends in pediatric imaging support the rising use of alternative imaging modalities, such as US and MRI, to decrease radiation exposure and to answer specific clinical questions and during the observation period also. As an example, ultrasound is the first technique of choice for the diagnosis and treatment of pleural and pericardial effusion; its emerging indications include the evaluation of pneumothoraces, costocondral and rib fractures, and even pulmonary contusions.

The use of whole body computed tomography scans in pediatric trauma patients: Are there differences among adults and pediatric centers?

INTRODUCTION

Whole body CT (WBCT) scan is known to be associated with significant radiation risk especially in pediatric trauma patients. The aim of this study was to assess the use WBCT scan across trauma centers for the management of pediatric trauma patients.

METHODS

We performed a two year (2011-2012) retrospective analysis of the National Trauma Data Bank. Pediatric (age≤18years) trauma patients managed in level I or II adult or pediatric trauma centers with a head, neck, thoracic, or abdominal CT scan were included. WBCT scan was defined as CT scan of the head, neck, thorax, and abdomen. Patients were stratified into two groups: patients managed in adult centers and patients managed in designated pediatric centers. Outcome measure was use of WBCT. Multivariate logistic regression analysis was performed.

RESULTS

A total of 30,667 pediatric trauma patients were included of which; 38.3% (n=11,748) were managed in designated pediatric centers. 26.1% (n=8013) patients received a WBCT. The use of WBCT scan was significantly higher in adult trauma centers in comparison to pediatric centers (31.4% vs. 17.6%, p=0.001). There was no difference in mortality rate between the two groups (2.2% vs. 2.1%, p=0.37). After adjusting for all confounding factors, pediatric patients managed in adult centers were 1.8 times more likely to receive a WBCT compared to patients managed in pediatric centers (OR [95% CI]: 1.8 [1.3-2.1], p=0.001).

CONCLUSIONS

Variability exists in the use of WBCT scan across trauma centers with no difference in patient outcomes. Pediatric patients managed in adult trauma centers were more likely to be managed with WBCT, increasing their risk for radiation without a difference in outcomes. Establishing guidelines for minimizing the use of WBCT across centers is warranted.

Prevalence and Clinical Import of Thoracic Injury Identified by Chest Computed Tomography but Not Chest Radiography in Blunt Trauma: Multicenter Prospective Cohort Study

STUDY OBJECTIVE

Chest computed tomography (CT) diagnoses more injuries than chest radiography, so-called occult injuries. Wide availability of chest CT has driven substantial increase in emergency department use, although the incidence and clinical significance of chest CT findings have not been fully described. We determine the frequency, severity, and clinical import of occult injury, as determined by changes in management. These data will better inform clinical decisions, need for chest CT, and odds of intervention.

METHODS

Our sample included prospective data (2009 to 2013) on 5,912 patients at 10 Level I trauma center EDs with both chest radiography and chest CT at physician discretion. These patients were 40.6% of 14,553 enrolled in the parent study who had either chest radiography or chest CT. Occult injuries were pneumothorax, hemothorax, sternal or greater than 2 rib fractures, pulmonary contusion, thoracic spine or scapula fracture, and diaphragm or great vessel injury found on chest CT but not on preceding chest radiography. A priori, we categorized thoracic injuries as major (having invasive procedures), minor (observation or inpatient pain control >24 hours), or of no clinical significance. Primary outcome was prevalence and proportion of occult injury with major interventions of chest tube, mechanical ventilation, or surgery. Secondary outcome was minor interventions of admission rate or observation hours because of occult injury.

RESULTS

Two thousand forty-eight patients (34.6%) had chest injury on chest radiography or chest CT, whereas 1,454 of these patients (71.0%, 24.6% of all patients) had occult injury. Of these, in 954 patients (46.6% of injured, 16.1% of total), chest CT found injuries not observed on immediately preceding chest radiography. In 500 more patients (24.4% of injured patients, 8.5% of all patients), chest radiography found some injury, but chest CT found occult injury. Chest radiography found all injuries in only 29.0% of injured patients. Two hundred and two patients with occult injury (of 1,454, 13.9%) had major interventions, 343 of 1,454 (23.6%) had minor interventions, and 909 (62.5%) had no intervention. Patients with occult injury included 514 with pulmonary contusions (of 682 total, 75.4% occult), 405 with pneumothorax (of 597 total, 67.8% occult), 184 with hemothorax (of 230 total, 80.0% occult), those with greater than 2 rib fractures (n=672/1,120, 60.0% occult) or sternal fracture (n=269/281, 95.7% occult), 12 with great vessel injury (of 18 total, 66.7% occult), 5 with diaphragm injury (of 6, 83.3% occult), and 537 with multiple occult injuries. Interventions for patients with occult injury included mechanical ventilation for 31 of 514 patients with pulmonary contusion (6.0%), chest tube for 118 of 405 patients with pneumothorax (29.1%), and 75 of 184 patients with hemothorax (40.8%). Inpatient pain control or observation greater than 24 hours was conducted for 183 of 672 patients with rib fractures (27.2%) and 79 of 269 with sternal fractures (29.4%). Three of 12 (25%) patients with occult great vessel injuries had surgery. Repeated imaging was conducted for 50.6% of patients with occult injury (88.1% chest radiography, 11.9% chest CT, 7.5% both). For patients with occult injury, 90.9% (1,321/1,454) were admitted, with 9.1% observed in the ED for median 6.9 hours. Forty-four percent of observed patients were then admitted (4.0% of patients with occult injury).

CONCLUSION

In a more seriously injured subset of patients with blunt trauma who had both chest radiography and chest CT, occult injuries were found by chest CT in 71% of those with thoracic injuries and one fourth of all those with blunt chest trauma. More than one third of occult injury had intervention (37.5%). Chest tubes composed 76.2% of occult injury major interventions, with observation or inpatient pain control greater than 24 hours in 32.4% of occult fractures. Only 1 in 20 patients with occult injury was discharged home from the ED. For these patients with blunt trauma, chest CT is useful to identify otherwise occult injuries.

The incidental pulmonary nodule in a child. Part 2: Commentary and suggestions for clinical management, risk communication and prevention

The incidental detection of small lung nodules in children is a vexing consequence of an increased reliance on CT. We present an algorithm for the management of lung nodules detected on CT in children, based on the presence or absence of symptoms, the presence or absence of elements in the clinical history that might explain these nodules, and the imaging characteristics of the nodules (such as attenuation measurements within the nodule). We provide suggestions on how to perform a thoughtfully directed and focused search for clinically occult extrathoracic disease processes (including malignant disease) that may present as an incidentally detected lung nodule on CT. This algorithm emphasizes that because of the lack of definitive information on the natural history of small solid nodules that are truly detected incidentally, their clinical management is highly dependent on the caregivers' individual risk tolerance. In addition, we present strategies to reduce the prevalence of these incidental findings, by preventing unnecessary chest CT scans or inadvertent inclusion of portions of the lungs in scans of adjacent body parts. Application of these guidelines provides pediatric radiologists with an important opportunity to practice patient-centered and evidence-based medicine.

Variations in the intensive use of head CT for elderly patients with hemorrhagic stroke

PURPOSE

To investigate the variability in head computed tomographic (CT) scanning in patients with hemorrhagic stroke in U.S. hospitals, its association with mortality, and the number of different physicians consulted.

MATERIALS AND METHODS

The study was approved by the Committee for the Protection of Human Subjects at Dartmouth College. A retrospective analysis of the Medicare fee-for-service claims data was performed for elderly patients admitted for hemorrhagic stroke in 2008-2009, with 1-year follow-up through 2010. Risk-adjusted primary outcome measures were mean number of head CT scans performed and high-intensity use of head CT (six or more head CT scans performed in the year after admission). We examined the association of high-intensity use of head CT with the number of different physicians consulted and mortality.

RESULTS

A total of 53 272 patients (mean age, 79.6 years; 31 377 women [58.9%]) with hemorrhagic stroke were identified in the study period. The mean number of head CT scans conducted in the year after admission for stroke was 3.4; 8737 patients (16.4%) underwent six or more scans. Among the hospitals with the highest case volume (more than 50 patients with hemorrhagic stroke), risk-adjusted rates ranged from 8.0% to 48.1%. The correlation coefficient between number of physicians consulted and rates of high-intensity use of head CT was 0.522 (P < .01) for all hospitals and 0.50 (P < .01) for the highest-volume hospitals. No improvement in 1-year mortality was found for patients undergoing six or more head CT scans (odds ratio, 0.84; 95% confidence interval: 0.69, 1.02).

CONCLUSION

High rates of head CT use for patients with hemorrhagic stroke are frequently observed, without an association with decreased mortality. A higher number of physicians consulted was associated with high-intensity use of head CT.

Nuking the radiation: minimizing radiation exposure in the evaluation of pediatric blunt trauma

PURPOSE OF REVIEW

Our objective is to highlight recent literature investigating low-radiation diagnostic strategies in the evaluation of pediatric trauma.

RECENT FINDINGS

In the area of minor head injury, research has focused on implementation of validated clinical decision rules into practice to reduce unnecessary computed tomography scans. Clinical observation may also serve as an adjunct to initial assessment and a potential substitute for computed tomography imaging. Subgroups of children with special needs or severe injury mechanisms may also be safely characterized by the clinical decision rule and spared radiation exposure. Physical examination techniques may be useful in diagnosing mandibular fractures. In addition, evidence suggests that plain radiography for evaluation of blunt thoracic trauma may be sufficient in many cases, and computed tomography could be reserved for those with abnormal radiographs, high-risk mechanisms, or abnormal physical findings. Clinical decision rules are able to predict intra-abdominal injury with high sensitivity. Data suggest that skeletal surveys may be modified to limit radiation exposure in the case of suspected nonaccidental trauma.

SUMMARY

More research is needed in development of pediatric-specific clinical decision rules and risk stratification and in testing low-radiation diagnostic modalities in the pediatric trauma population.

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.

Focused Assessment with Sonography in Trauma and Abdominal Computed Tomography Utilization in Adult Trauma Patients: Trends over the Last Decade

Objective. We sought to describe the trend in abdominal CT use in adult trauma patients after a point-of-care emergency ultrasound program was introduced. We hypothesized that abdominal CT use would decrease as FAST use increased. Methods. We performed a retrospective study of 19940 consecutive trauma patients over the age of 18 admitted to our level one trauma center from 2002 through 2011. Data was collected retrospectively and recorded in a trauma registry. We plotted the rate of FAST and abdominal CT utilization over time. Head CT was used as a surrogate for overall CT utilization rates during the study period. Results. Use of FAST increased by an average of 2.3% (95% CI 2.1 to 2.5, P < 0.01) while abdominal CT use decreased by the same rate annually. The percentage of patients who received FAST as the sole imaging modality for the abdomen rose from 2.0% to 21.9% while those who only received an abdominal CT dropped from 21.7% to 2.3%. Conclusions. Abdominal CT use in our cohort declined while FAST utilization grew in the last decade. The rising use of FAST may have played a role in the reduction of abdominal CT performed as decline in CT utilization appears contrary to overall trends.

Digital tomosynthesis of the thorax: the influence of respiratory motion artifacts on lung nodule detection

BACKGROUND

Digital tomosynthesis considerably reduces problems created by overlapping anatomy compared with chest X-ray (CXR). However, digital tomosynthesis requires a longer scan time compared with CXR, and thus may be vulnerable to motion artifacts.

PURPOSE

To compare the diagnostic performance of digital tomosynthesis in subjects with and without respiratory motion artifacts.

MATERIAL AND METHODS

The institutional review board approved this retrospective study, and the requirement for written informed consent was waived. A total of 46 subjects with imaging containing respiratory motion artifacts were enrolled in this study, 18 of whom were positive and 28 of whom were negative for lung nodules on computed tomography (CT). The control group was comprised of 92 age-matched subjects with imaging devoid of motion artifacts. Of these, 36 were positive and 56 were negative for lung nodules on subsequent CT scan. The size criteria of nodules were 4-10 mm. Three chest radiologists independently evaluated the radiographs and digital tomosynthesis images for the presence of pulmonary nodules. Multireader multicase receiver-operating characteristic (ROC) analyses was used for statistical comparisons.

RESULTS

Within the control group, the areas under curve (AUC) for observer performances in detecting lung nodules on digital tomosynthesis was higher than that on CXR (P = 0.017). Within the study group, there were no significant differences in AUCs for observer performances (P = 0.576).

CONCLUSION

When no motion artifacts are present, the detection performance of nodules (4-10 mm) on digital tomosynthesis is significantly better than that on CXR, whereas there is not a significant difference in cases with motion artifacts.

Nuances in pediatric trauma

Pediatric trauma evaluation mimics adult stabilization in that it is best accomplished with a focused and systematic approach. Attention to developmental differences, anatomic and physiologic nuances, and patterns of injury equip emergency physicians to stabilize and manage pediatric injury.

Management of chest trauma in children

Chest trauma in children is caused by high-energy blows, due in general to traffic accidents, that involve several other body regions. They occur mainly in the first decade of life and can be penetrating but are more often non-penetrating. Rib fractures and lung contusions, sometimes associated with pneumothorax or haemothorax, are the more usual injuries, but tracheobronchial rupture, cardiac, oesophageal or diaphragmatic injuries may also occur. These injuries are treated with supportive respiratory and haemodynamic measures, drainage of air or blood from the pleural space and, at times, surgical repair of the injured organ(s). Ruptures of the airway may be difficult to treat and occasionally require suture, anastomosis or resection. Oesophageal injuries can be treated conservatively with antibiotics, drainage and parenteral nutrition. Diaphragmatic tears should be repaired operatively. Overall mortality ranges from 6 to 20%. Mortality is high but this is mainly due to the associated presence of extra-thoracic trauma, and particularly to head injuries.

Management of blunt tracheobronchial trauma in the pediatric age group

INTRODUCTION

Tracheobronchial rupture (TBR) due to blunt chest trauma is a rare but life-threatening injury in the pediatric age group. The aim of this study was to propose a treatment strategy including bronchoscopy, surgery and extracorporeal membrane oxygenation (ECMO) to optimize the emergency management of these patients.

METHODS

We reviewed a series of 27 patients with post-traumatic TBR treated since 1996 in our pediatric trauma center.

RESULTS

Seven cases had persistent and large volume air leaks. Flexible bronchoscopy was performed in cases of persistent or large volume air leaks. It permitted accurate visualization of the rupture and its extent. It allowed for a clear-cut positioning of the endotracheal tube. Five were managed operatively. Four cases were considered to be life-threatening because of the combination of severe respiratory distress with hemodynamic instability. One of them had severe tracheal laceration and died. Another one had bilateral bronchi disconnection. Based on clinical and endoscopic findings, surgical repair was performed using extracorporeal membrane oxygenation as a ventilatory support. It provided quick relief from the injury, which was previously expected to result in a fatal issue.

CONCLUSIONS

Prompt diagnosis and accurate management of surviving patients admitted to emergency rooms are necessary. Bronchoscopy remains a critical diagnosis step. Surgery is warranted for large tracheobronchial tears and ECMO could be beneficial as supportive therapy for selected cases.

Perioperative management of pediatric trauma patients

Pediatric trauma presents significant challenges to the anesthesia provider.

This review describes the current trends in perioperative anesthetic management, including airway management, choice of anesthesia agents, and fluid administration.

The review is based on the PubMed search of literature on perioperative care of severely injured children.

Computed Tomography Associated Cancers and Cancer Deaths Following Visits to U.S. Emergency Departments

We estimated the number of future cancers and cancer deaths following computed tomography scans (CTs) performed in U.S. emergency departments annually and determined whether increases in the proportion of visits resulting in CTs over the past decade were accompanied by changes in markers of severity of illness or primary reason for visit. We applied national estimates of effective dose to adult emergency department visits in the 2008 National Hospital Ambulatory Medical Care Survey. We utilized the Biologic Effects of Ionizing Radiation Model VII to estimate the number of future cancers and cancer deaths caused by CTs performed in U.S. emergency departments. We calculated the proportion of visits resulting in CTs from 1998 to 2008. In 2008, 16,406,921 CTs were performed nationally on adults, which will cause an estimated 3,750 cancers and 1,994 cancer deaths. The increasing proportion of emergency department visits resulting in CTs was not accompanied by proportional increases in markers of severity of illness or primary reason for visit. The substantial number of future cancers and cancer deaths attributable to CTs and increases in CTs without accompanying increases in markers of severity or changes in primary reason for visit highlight the importance of examining the benefits of CTs.

CT Scans in Young People in Great Britain: Temporal and Descriptive Patterns, 1993-2002

Background. Although using computed tomography (CT) can be greatly beneficial, the associated relatively high radiation doses have led to growing concerns in relation to potential associations with risk of future cancer. Very little has been published regarding the trends of CT use in young people. Therefore, our objective was to assess temporal and other patterns in CT usage among patients aged under 22 years in Great Britain from 1993 to 2002. Methods. Electronic data were obtained from the Radiology Information Systems of 81 hospital trusts within Great Britain. All included patients were aged under 22 years and examined using CT between 1993 and 2002, with accessible radiology records. Results. The number of CT examinations doubled over the study period. While increases in numbers of recorded examinations were seen across all age groups, the greatest increases were in the older patients, most notably those aged 15-19 years of age. Sixty percent of CT examinations were of the head, with the percentages varying with calendar year and patient age. Conclusions. In contrast to previous data from the North of England, the doubling of CT use was not accompanied by an increase in numbers of multiple examinations to the same individual.

Educational paper: imaging child abuse: the bare bones

Fractures are reported to be the second most common findings in child abuse, after skin lesions such as bruises and contusions. This makes careful interpretation of childhood fractures in relation to the provided clinical history important. In this literature review, we address imaging techniques and the prevailing protocols as well as fractures, frequently seen in child abuse, and the differential diagnosis of these fractures. The use of a standardised protocol in radiological imaging is stressed, as adherence to the international guidelines has been consistently poor. As fractures are a relatively common finding in childhood and interpretation is sometimes difficult, involvement of a paediatric radiologist is important if not essential. Adherence to international guidelines necessitates review by experts and is therefore mandatory. As in all clinical differential diagnoses, liaison between paediatricians and paediatric radiologists in order to obtain additional clinical information or even better having joint review of radiological studies will improve diagnostic accuracy. It is fundamental to keep in mind that the diagnosis of child abuse can never be solely based on radiological imaging but always on a combination of clinical, investigative and social findings. The quality and interpretation, preferably by a paediatric radiologist, of radiographs is essential in reaching a correct diagnosis in cases of suspected child abuse.

Fast scanning tomosynthesis for the detection of pulmonary nodules: diagnostic performance compared with chest radiography, using multidetector-row computed tomography as the reference

OBJECTIVES

: To evaluate the diagnostic performance of fast scanning tomosynthesis in comparison with that of chest radiography for the detection of pulmonary nodules, using multidetector-row computed tomography (MDCT) as the reference, and to assess the association of the true-positive fraction (TPF) with the size, CT attenuation value, and location of the nodules.

MATERIALS AND METHODS

: The institutional review board approved this study, and written informed consent was obtained from all patients. Fifty-seven patients with and 59 without pulmonary nodules underwent chest MDCT, fast scanning tomosynthesis, and radiography. The images of tomosynthesis and radiography were randomly read by 3 blinded radiologists; MDCT served as the reference standard. Free-response receiver-operating characteristic (FROC) and receiver-operating characteristic (ROC) analyses, Cochran-Armitage trend or Fisher exact test, a conditional logistic regression model, and McNemar test were used.

RESULTS

: Both FROC and ROC analyses revealed significantly better performance (P < 0.01) of fast scanning tomosynthesis than radiography for the detection of pulmonary nodules. For fast scanning tomosynthesis, the average TPF and false-positive rate as determined by FROC analysis were 0.80 and 0.10, respectively. For both fast scanning tomosynthesis and radiography, the average TPF increased with increasing nodule size and CT attenuation values, and was lower for subpleural nodules (all P < 0.01).

CONCLUSIONS

: The diagnostic performance of fast scanning tomosynthesis for the detection of pulmonary nodules was significantly superior to that of radiography. The TPF was affected by the size, CT attenuation value, and location of the nodule, in both fast scanning tomosynthesis and radiography.

CT scans in young people in Northern England: trends and patterns 1993-2002

BACKGROUND

Although CT can be greatly beneficial, its relatively high radiation doses have caused public health concerns.

OBJECTIVE

To assess patterns in CT usage among patients aged less than 22 years in Northern England during the period 1993-2002.

MATERIALS AND METHODS

Electronic data were obtained from radiology information systems of all nine National Health Service trusts in the region.

RESULTS

A total of 38,681 scans had been performed in 20,483 patients aged less than 22 years. The number of CT examinations rose, with the steepest increase between 1997 and 2000. The number of patients scanned per year increased less dramatically, with 2.24/1,000 population aged less than 22 years having one scan or more in 1993 compared to 3.54/1,000 in 2002. This reflects an increase in the median number of scans per patient, which rose from 1 in 1993 to 2 by 1999. More than 70% of CT examinations were of the head, with the number of head examinations varying with time and patient age.

CONCLUSION

The frequency of CT scans in this population more than doubled during the study period. This is partly, but not wholly, explained by an increase in the number of scans per patient.

Value of postmortem thoracic CT over radiography in imaging of pediatric rib fractures

BACKGROUND

Studies have reported that thoracic CT may provide greater sensitivity compared with radiography in detection of pediatric rib fractures and fracture healing. The additional sensitivity afforded by thoracic CT may have medicolegal implications where abuse is suspected.

OBJECTIVE

To determine the additional value of postmortem thoracic CT compared with radiography in detecting pediatric rib fractures, and fracture healing, using autopsy findings as a gold standard.

MATERIALS AND METHODS

We retrospectively reviewed 56 coroner's cases with postmortem radiography and CT thoracic survey. All studies underwent primary interpretation by one or two radiologists. The study radiologist independently reviewed all images from 13 patients with positive findings on radiography, CT or autopsy. Sensitivity and specificity between observers and imaging modalities were compared.

RESULTS

Primary interpretation: Fractures were recognized on radiography in 5/12 patients who had fractures found at autopsy, and on CT in 8/12 patients. In total, 29% (24/83) of fractures were reported on radiography, and 51% (52/101) of fractures were reported on CT. Study radiologist: Fractures were recognized on radiography in 7/12 patients who had fractures found at autopsy, and on CT in 11/12 patients. In total, 46% (38/83) of fractures were reported on radiography, and 85% (86/101) of fractures were reported on CT.

CONCLUSION

Postmortem thoracic CT provides greater sensitivity than radiography in detecting pediatric rib fractures, most notably in anterior and posterior fractures. However, the degree of improvement in sensitivity provided by CT might depend on observer experience.

Usefulness of computerized method for lung nodule detection on digital chest radiographs using similar subtraction images from different patients

PURPOSE

The purpose of this study is to evaluate the usefulness of a novel computerized method to select automatically the similar chest radiograph for image subtraction in the patients who have no previous chest radiographs and to assist the radiologists' interpretation by presenting the "similar subtraction image" from different patients.

MATERIALS AND METHODS

Institutional review board approval was obtained, and the requirement for informed patient consent was waived. A large database of approximately 15,000 normal chest radiographs was used for searching similar images of different patients. One hundred images of candidates were selected according to two clinical parameters and similarity of the lung field in the target image. We used the correlation value of chest region in the 100 images for searching the most similar image. The similar subtraction images were obtained by subtracting the similar image selected from the target image. Thirty cases with lung nodules and 30 cases without lung nodules were used for an observer performance test. Four attending radiologists and four radiology residents participated in this observer performance test.

RESULTS

The AUC for all radiologists increased significantly from 0.925 to 0.974 with the CAD (P=.004). When the computer output images were available, the average AUC for the residents was more improved (0.960 vs. 0.890) than for the attending radiologists (0.987 vs. 0.960).

CONCLUSION

The novel computerized method for lung nodule detection using similar subtraction images from different patients would be useful to detect lung nodules on digital chest radiographs, especially for less experienced readers.

Pediatric chest CT after trauma: impact on surgical and clinical management

BACKGROUND

Chest CT after pediatric trauma is frequently performed but its clinical impact, particularly with respect to surgical intervention, has not been adequately evaluated.

OBJECTIVE

To assess the impact of chest CT compared with chest radiography on pediatric trauma management.

MATERIALS AND METHODS

Two hundred thirty-five consecutive pediatric trauma patients who had both chest CT and radiography were identified. Images were reviewed and findings were categorized and correlated with subsequent chest interventions, blinded to final outcome and management.

RESULTS

Of the 235 children, 38.3% (90/235) had an abnormal chest radiograph and 63.8% (150/235) had an abnormal chest CT (P < 0.0001). Chest interventions followed in 4.7% (11/235); of these, the findings could be made 1 cm above the dome of the liver in 91% (10/11). Findings requiring chest intervention included pneumothorax (PTX) and vertebral fractures. PTX was found on 2.1% (5/235) of chest radiographs and 20.0% (47/235) of chest CTs (P < 0.0001); 1.7% (4/235) of the children received a chest tube for PTX, 0.85% (2/235) seen on chest CT only. Vertebral fractures were present in 3.8% of the children (9/235) and 66.7% (6/9) of those cases were treated with spinal fusion or brace. There were no instances of mediastinal vascular injury.

CONCLUSION

Most intrathoracic findings requiring surgical management in our population were identified in the lower chest and would be included in routine abdominopelvic CT exams; this information needs to be taken into consideration in the diagnostic algorithm of pediatric trauma patients.

Overview of two years of clinical experience of chest tomosynthesis at Sahlgrenska University Hospital

Since December 2006, approximately 3800 clinical chest tomosynthesis examinations have been performed at our department at Sahlgrenska University Hospital. A subset of the examinations has been included in studies of the detectability of pulmonary nodules, using computed tomography (CT) as the gold standard. Visibility studies, in which chest tomosynthesis and CT have been compared side-by side, have been used to determine the depiction potential of chest tomosynthesis. Comparisons with conventional chest radiography have been made. In the clinical setting, chest tomosynthesis has mostly been used as an additional examination. The most frequent indication for chest tomosynthesis has been suspicion of a nodule or tumour. In visibility studies, tomosynthesis has depicted over 90 % of the nodules seen on the CT scan. The corresponding figure for chest radiography has been <30 %. In the detection studies, the lesion-level sensitivity has been approximately 60 % for tomosynthesis and 20 % for chest radiography. In one of the detection studies, an analysis of all false-positive nodules was performed. This analysis showed that all findings had morphological correlates on the CT examinations. The majority of the false-positive nodules were localised in the immediate subpleural region. In conclusion, chest tomosynthesis is an improved chest radiography method, which can be used to optimise the use of CT resources, thereby reducing the radiation dose to the patient population. However, there are some limitations with chest tomosynthesis. For example, patients undergoing tomosynthesis have to be able to stand still and hold their breath firmly for 10 s. Also, chest tomosynthesis has a limited depth resolution, which may explain why pathology in the subpleural region is more difficult to interpret and artefacts from medical devices may occur.

Lung contusion in children--early computed tomography versus radiography

OBJECTIVE

To investigate, in children, the correlation between the extent of lung contusion as detected on early radiologic examination (chest radiograph [CXR] and/or thoracic computed tomography [TCT]) and subsequent clinical outcome measures.

DESIGN

Retrospective chart review study with blinded assessment of thoracic imaging.

SETTING

A university-affiliated, level 1 designated pediatric trauma center.

INTERVENTIONS

None.

PATIENTS

Patients (1-18 yrs) who, between April 2000 and October 2005, were diagnosed with lung contusion were eligible for study entry. The medical records of those patients who underwent early (within the first 24 hrs of admission) thoracic imaging (CXR and/or TCT) were reviewed. A pulmonary contusion score (PCS) was assigned to each thoracic image according to the extent of contusion injury by two investigators blinded to each others score and the clinical details of the patient.

RESULTS

Seventy-four patients were included in the study. Twenty patients had undergone CXR only, whereas 54 had undergone both CXR and TCT. The mean PCS on CXR was 3.9 +/- 3.6 compared with 6.5 +/- 3.49 on TCT (p < .001). In eight patients (15%) who underwent TCT and CXR, the CXR failed to demonstrate a lung contusion. The PCS derived from CXR examination correlated positively with lower Pao2/Fio2 (r = -.36, p = .019), higher ventilation index (r = .35, p = .014), and longer length of ventilation (r = .28, p = .019). No such correlation was seen with TCT-derived PCS.

CONCLUSIONS

The severity of lung contusion determined by CXR, but not TCT, correlates with impairment of oxygenation, CO2 exchange, and duration of ventilatory support.

Skeletal imaging of child abuse (non-accidental injury)

In recent years there has been a worldwide increased awareness that children are physically abused by their carers. Radiologists play a vital role in the detection of inflicted injuries. This article reviews the skeletal imaging findings seen in child abuse.

[Thoracic and abdominal trauma in children]

Knowledge of the characteristics of thoraco-abdominal trauma in children is important to optimize the imaging work up while keeping radiation exposure to a minimum. Because of the plasticity of the pediatric rib cage, rib fractures are infrequent, and severe parenchymal injuries may be present in the absence of rib fracture. Mediastinal injuries are unusual. The increased mobility of solid intraabdominal organs combined with a weaker abdominal wall are specific to pediatric patients. First-line imaging typically includes chest radiograph and abdominal US with Doppler imaging. Contrast-material enhanced CT is used as a second-line technique, with delayed imaging in patients with urinary tract lesions. Dedicated pediatric acquisition protocols are mandatory. Follow-up is obtained mainly with US.

Traumatic cervical spine injuries: characteristics of missed injuries

PURPOSE

Computed tomographic (CT) scanning has mostly replaced x-rays as an imaging modality, but concerns exist because of excess radiation, missed injuries, and whether it is the definitive procedure for intubated patients. The purpose of this study was to characterize missed cervical spine injuries (CSIs).

METHODS

All pediatric (<18) trauma patients from 2004 to 2006 were analyzed. Age, sex, Injury Severity Score (ISS), mechanism, time, and missed injuries were reviewed. Flexion/extension views were used in patients with prolonged intubation. Descriptive statistics, chi(2), Student's t test, and bivariate correlation were used.

RESULTS

There were 1307 pediatric trauma patients admitted with 318 imaged for potential CSI. Computed tomography was the sole imaging study in 200, x-rays in 64, and both in 54. Time to C-spine clearance was similar for all modalities (P > .05). For CT, 34 (10.7%) were initially positive for CSI with 7 false-positives (FPs) and no false-negative (FN). There were 18 patients with CSI identified by x-ray, with 5 FPs and 5 FNs (missed injuries). The 5 FNs missed by x-ray were all positive by CT scan and required no intervention. None of the flexion/extension views revealed an additional injury. Sex, intubated patients, ISS, age, type, and injury location were not predictive of a missed injury (P > .05).The sensitivity of CT scan was 1.0, specificity was 0.976, and the positive predictive value was 79.4%. The sensitivity of plain x-ray was 61.5%, the specificity was 1.6%, and the positive predictive value was 61.5%.

CONCLUSIONS

Our data suggest that CT scans should be the primary modality to image a CSI. Flexion/extension views did not add to the decision making for C-spine clearance after CT evaluation.

The role of chest computed tomography in trauma

Chest computed tomography (CCT) evaluation for trauma encompasses two main objectives: (1) The evaluation of the acutely injured in the search for diagnoses and (2) follow up assessment or diagnosis of pulmonary complications in the hospitalised patient. In the acute phase of evaluation, CCT has become particularly helpful for the diagnosis of blunt thoracic aortic injury (BAI), great vessel injury, extent of lung contusion, occult hemothorax, occult pneumothorax, spinal fractures and spinal cord injuries and to determine the tract of transmediastinal gun shot wounds. In the subacute phase, CCT has gained popularity for diagnosing pulmonary embolism and evaluation of retained hemothorax. Technological advances have lead to better diagnostic capabilities that can be obtained quickly but, particularly in the trauma patient, there is little consistent data supporting an outcome improvement in the majority of patients despite changes in clinical management. Further data is needed to support use of CCT in select trauma patient populations to increase useful diagnostic yield and cost effectiveness.

Experiences in severe chest trauma of children in 20 years

Though chest trauma in children is not so common as it is in adults, it may be life-threatening and suggest a high mortality. Herein we retrospected 59 cases of severe chest trauma of children out of 1506 chest trauma cases during 1986-2006 in our department. Features including demographic characteristics, causes, injury types, associated wound had been collected. There were 42 males (71.18%), 17 females (28.82%), 30 cases (50.84%) in the former 10 years and 29 cases (49.16%) in the latter 10 years. The incidence of children's severe chest trauma was 4.9% and 3.2%, respectively, averagely 3.9%. In these 59 cases, 46 cases were treated conservatively, 13 cases were treated by surgery. Four patients died, two in operations, the others attributed to ARDS and cardiac arrest, respectively. The cure rate was 93.22%. Statistic method was used to compare between two groups and with published results in the literature. Children's severe chest trauma is characteristic and different from adults. In our experience, accurate diagnoses and intensive care are very important to save their lives.

Diagnostic techniques in thoracic trauma

Diagnosis of thoracic injury begins with a history of events and examination of the patient. Appropriate radiographic studies will be dictated by the findings on history and physical. Procedural examinations, such as endoscopy or angiography, may also be needed for accurate diagnosis.

Cancer risks from diagnostic radiology

In recent years, there has been a rapid increase in the number of CT scans performed, both in the US and the UK, which has fuelled concern about the long-term consequences of these exposures, particularly in terms of cancer induction. Statistics from the US and the UK indicate a 20-fold and 12-fold increase, respectively, in CT usage over the past two decades, with per caput CT usage in the US being about five times that in the UK. In both countries, most of the collective dose from diagnostic radiology comes from high-dose (in the radiological context) procedures such as CT, interventional radiology and barium enemas; for these procedures, the relevant organ doses are in the range for which there is now direct credible epidemiological evidence of an excess risk of cancer, without the need to extrapolate risks from higher doses. Even for high-dose radiological procedures, the risk to the individual patient is small, so that the benefit/risk balance is generally in the patients' favour. Concerns arise when CT examinations are used without a proven clinical rationale, when alternative modalities could be used with equal efficacy, or when CT scans are repeated unnecessarily. It has been estimated, at least in the US, that these scenarios account for up to one-third of all CT scans. A further issue is the increasing use of CT scans as a screening procedure in asymptomatic patients; at this time, the benefit/risk balance for any of the commonly suggested CT screening techniques has yet to be established.

Comparison of computed tomography and chest radiography in the detection of rib fractures in abused infants

PURPOSE

Chest radiographs (CXR) are the standard method for evaluating rib fractures in abused infants. Computed tomography (CT) is a sensitive method to detect rib fractures. The purpose of this study was to compare CT and CXR in the evaluation of rib fractures in abused infants.

METHODS

This retrospective study included all 12 abused infants identified from 1999 to 2004 who had rib fractures and both CXR and CT (8 abdomen CTs, 4 chest CTs). CT exams had been performed for clinical indications, and were obtained within one day of the CXR. Studies were reviewed by two pediatric radiologists to determine the number, locations, and approximate ages of the rib fractures. A total of 225 ribs were completely (192) or partially (33) seen by CT, and the matched ribs on CXR were used for the analysis.

RESULTS

The mean patient age was 2.5 months (1.2-5.6), with seven females and five males. While 131 fractures were visualized by CT, only 79 were seen by CXR (p<.001). One patient had fractures only seen by CT. There were significantly (p<.05) more early subacute (24 vs. 4), subacute (47 vs. 26), and old fractures (4 vs. 0) seen by CT than by CXR. Anterior (42 vs. 11), anterolateral (21 vs. 12), posterolateral (9 vs. 3) and posterior (39 vs. 24) fractures were better seen by CT than by CXR (p<.01). Bilateral fractures were detected more often by CT (11) than by CXR (6).

CONCLUSIONS

While this study group is small, these findings suggest that CT is better than CXR in visualizing rib fractures in abused infants.