Imaging issues in CT of blunt trauma to the chest and abdomen

Urgent and emergent pediatric cardiovascular imaging

The need for urgent or emergent cardiovascular imaging in children is rare when compared to adults. Patients may present from the neonatal period up to adolescence, and may require imaging for both traumatic and non-traumatic causes. In children, coronary pathology is rarely the cause of an emergency unlike in adults where it is the main cause. Radiology, including chest radiography and computed tomography in conjunction with echocardiography, often plays the most important role in the acute management of these patients. Magnetic resonance imaging can occasionally be useful and may be suitable in more subacute cases. Radiologists' knowledge of how to manage and interpret these acute conditions including knowing which imaging technique to use is fundamental to appropriate care. In this review, we will concentrate on the most common cardiovascular emergencies in the thoracic region, including thoracic traumatic and non-traumatic emergencies and pulmonary vascular emergencies, as well as acute clinical disorders as a consequence of primary and postoperative congenital heart disease. This review will cover situations where cardiovascular imaging may be acutely needed, and not strictly emergencies only. Imaging recommendations will be discussed according to the different clinical presentations and underlying pathology.

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.

Diagnostic imaging of blunt abdominal trauma in pediatric patients

Trauma is a leading cause of morbidity and mortality in childhood, and blunt trauma accounts for 80-90 % of abdominal injuries. The mechanism of trauma is quite similar to that of the adults, but there are important physiologic differences between children and adults in this field, such as the smaller blood vessels and the high vasoconstrictive response, leading to the spreading of a non-operative management. The early imaging of children undergoing a low-energy trauma can be performed by CEUS, a valuable diagnostic tool to demonstrate solid organ injuries with almost the same sensitivity of CT scans; nevertheless, as for as urinary tract injuries, MDCT remains still the technique of choice, because of its high sensitivity and accuracy, helping to discriminate between an intra-peritoneal form a retroperitoneal urinary leakage, requiring two different managements. The liver is the most common organ injured in blunt abdominal trauma followed by the spleen. Renal, pancreatic, and bowel injuries are quite rare. In this review we present various imaging findings of blunt abdominal trauma in children.

Spleen Segmentation and Assessment in CT Images for Traumatic Abdominal Injuries

Spleen segmentation is especially challenging as the majority of solid organs in the abdomen region have similar gray level range. Physician analysis of computed tomography (CT) images to assess abdominal trauma could be very time consuming and hence, automating this process can reduce time to treatment. The proposed method presented in this paper is a fully automated and knowledge based technique that employs anatomical information to accurately segment the spleen in CT images. The spleen detection procedure is proposed to locate the spleen in both healthy and injured cases. In the presence of hemorrhage and laceration, the edge merging technique is used. The accuracy of the method is measured by some criteria such as mis-segmented area, accuracy, specificity and sensitivity. The results show that the proposed spleen segmentation method performs well and outperforms other methods.

Blunt polytrauma: evaluation with 64-section whole-body CT angiography

Blunt polytrauma remains a leading cause of death and disability worldwide. With the major advances in computed tomography (CT) technology over the past decade, whole-body CT is increasingly recognized as the emerging standard for providing rapid and accurate diagnoses within the narrow therapeutic window afforded to trauma victims with multiple severe injuries. With a single continuous acquisition, whole-body CT angiography is able to demonstrate all potentially injured organs, as well as vascular and bone structures, from the circle of Willis to the symphysis pubis. As its use becomes more widespread, the large volume of information inherent to whole-body CT poses new challenges to radiologists in providing efficient and timely interpretation. An awareness of trauma scoring systems and injury mechanisms is essential to maintain an appropriate level of suspicion in the search for multiple injuries, and the use of multiplanar reformation and three-dimensional postprocessing techniques is important to maximize efficiency in the search. Knowledge of the key injuries that require urgent surgical or percutaneous intervention, including major vascular injuries and active hemorrhage, diaphragmatic rupture, unstable spinal fractures, pancreatic injuries with ductal involvement, and injuries to the mesentery and hollow viscera, is also necessary.