Use of photon-counting CT and three-dimensional printing for an intra-thoracic retained ballistic fragment in a 9-year-old

Retained ballistic fragments from gunshot wounds pose diagnostic and management challenges for radiologists and surgeons alike. Imaging and clinical decision-making regarding removal warrant comprehensive risk/benefit discussions, considering anatomic location, complexity of surgical removal, and risk of long-term complications of bullet migration and potential lead toxicity. Herein, we describe a 9-year-old with a retained intra-thoracic para-aortic ballistic fragment causing elevated lead levels. Photon-counting detector computed tomography (PCD-CT) was used to create a 3D-printed anatomic model, critical for multidisciplinary pre-operative planning and as an educational tool with the patient and family, ultimately leading to successful surgical bullet removal. Since spectral CT imaging offers superior metal artifact reduction capabilities than conventional CT, cutting-edge technologies such as PCD-CT and 3D-printing should be considered in anatomically challenging cases.

ACR Appropriateness Criteria® Penetrating Torso Trauma

This document assesses the appropriateness of various imaging studies for acute penetrating trauma to the torso. Penetrating trauma most commonly occurs from gunshots and stabbings, although any object can impale the patient. Anatomic location, type of penetrating trauma, and hemodynamic status are among the many important factors when deciding upon if, what, and when imaging is needed to further evaluate the patient. Imaging plays a critical role in the management of these patients. CT, in particular, aids in identifying and predicting internal injuries based upon trajectory of the object. Clinical variants are distinguished by ballistic versus nonballistic injuries, hemodynamic status, and compartment of the body injured. Ballistic trauma trajectory is less predictable, and imaging recommendations are adjusted for this unpredictability. Excluded from this document are penetrating traumatic injuries to pediatric patients and specific recommendations when the genitourinary system is clinically suspected to be injured, the latter of which is more specifically discussed in other Appropriateness Criteria documents. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are documented annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer documented journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer documented literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Artificial intelligence in the detection of non-biological materials

Artificial Intelligence (AI) has emerged as a transformative force within medical imaging, making significant strides within emergency radiology. Presently, there is a strong reliance on radiologists to accurately diagnose and characterize foreign bodies in a timely fashion, a task that can be readily augmented with AI tools. This article will first explore the most common clinical scenarios involving foreign bodies, such as retained surgical instruments, open and penetrating injuries, catheter and tube malposition, and foreign body ingestion and aspiration. By initially exploring the existing imaging techniques employed for diagnosing these conditions, the potential role of AI in detecting non-biological materials can be better elucidated. Yet, the heterogeneous nature of foreign bodies and limited data availability complicates the development of computer-aided detection models. Despite these challenges, integrating AI can potentially decrease radiologist workload, enhance diagnostic accuracy, and improve patient outcomes.

Imaging of penetrating vascular trauma of the body and extremities secondary to ballistic and stab wounds

In the United States, gunshot wounds (GSWs) have become a critical public health concern with substantial annual morbidity, disability, and mortality. Vascular injuries associated with GSW may pose a clinical challenge to the physicians in the emergency department. Patients demonstrating hard signs require immediate intervention, whereas patients with soft signs can undergo further diagnostic testing for better injury delineation. Although digital subtraction angiography is the gold standard modality to assess vascular injuries, non-invasive techniques such as Doppler ultrasound, computed tomography angiography, and magnetic resonance angiography have evolved as appropriate alternatives. This article discusses penetrating bodily vascular injuries, specifically ballistic and stab wounds, and the corresponding radiological presentations.

CT of Penetrating Abdominopelvic Trauma

Penetrating abdominopelvic trauma usually results from abdominal cavity violation from a firearm injury or a stab wound and is a leading cause of morbidity and mortality from traumatic injuries. Penetrating trauma can have subtle or complex imaging findings, posing a diagnostic challenge for radiologists. Contrast-enhanced CT is the modality of choice for evaluating penetrating injuries, with good sensitivity and specificity for solid-organ and hollow viscus injuries. Familiarity with the projectile kinetics of penetrating injuries is an important skill set for radiologists and aids in the diagnosis of both overt and subtle injuries. CT trajectography is a useful tool in CT interpretation that allows the identification of subtle injuries from the transfer of kinetic injury from the projectile to surrounding tissue. In CT trajectography, after the entry and exit wounds are delineated, the two points can be connected by placing cross-cursors and swiveling the cut planes obliquely in orthogonal planes to obtain a double-oblique orientation to visualize the wound track in profile. The path of the projectile and its ensuing damage is not always straight, and the imaging characteristics of free fluid of different attenuation in the abdomen (including hemoperitoneum) can support the diagnosis of visceral and vascular injuries. In addition, CT is increasingly used for evaluation of patients after damage control surgery and helps guide the management of injuries that were overlooked at surgery. An invited commentary by Paes and Munera is available online. Online supplemental material is available for this article. ©RSNA, 2021.

Medical and surgical devices in the emergency and trauma patient: what the radiologist should know, and how they can add value

A variety of different external and internal medical devices are used in the acute setting to maintain life support and manage severely injured and unstable trauma or emergency patients. These devices are inserted into the acutely ill patient with the specific purpose of improving outcome, but misplacement can cause additional morbidity and mortality. Consequently, meaningful interpretation of the position of devices can affect acute management. Some devices such as nasopharyngeal, nasogastric and endotracheal tubes and chest and surgical drains are well known to most clinicians, however, little formal training exists for radiologists in composing their report on the imaging of these devices. The novice radiologist often relies on tips and phrases handed down in an aural tradition or resorts to phrases such as: "position as shown". Furthermore, radiologists with limited experience in trauma might not be familiar with the radiological appearance of other more specific devices. This review will focus on the most common medical devices used in acute trauma patients, indications, radiological appearance and their correct and suboptimal positioning.

Imaging Ballistic Injuries

Here in Canada, we often think of gun violence as confined to conflict zones, terrorism, and more of a problem for our southern neighbor. However, in recent years, it has also become a Canadian problem with increased gun violence related to criminal activity presenting in daily practice. Radiologists play a critical role in the evaluation of ballistic trauma and must therefore be familiar with both the common and uncommon patterns of ballistic injury. In this article, we review the mechanisms of ballistic trauma as well as their resultant injury patterns in order to guide image interpretation.

Imaging of penetrating thoracic trauma in a large Nordic trauma center

Background

Penetrating trauma is rarely encountered in Nordic trauma centers, yet the incidence is increasing. Typical imaging findings in penetrating trauma should thus be familiar to all radiologists.

Purpose

To evaluate incidence and imaging findings of penetrating chest trauma, gunshot wound (GSW) and stab wound (SW) injury spectrum, imaging protocols, and outcome in a large trauma center.

Material and Methods

Trauma registry data from 2013–2016 was retrieved, and imaging accessed through hospital PACS. Retrieved variables included age, gender, injury severity scores, mechanism of injury, time to CT, and 30-day mortality. Depth of thoracic, pulmonary, abdominal and skeletal injury, active bleeding, and use of chest tubes were evaluated.

Results

Of 636 patients with penetrating injuries, 443 (69.7%) underwent imaging. Of these, 161 (36.3%) had penetrating thoracic injuries. Of 161 patients with penetrating chest trauma in imaging, 151 (93.8%) were men (mean age = 34.9 years) and 10 (6.2%) were women (mean age = 40.7 years). The majority of patients had SWs (138 SW vs. 15 GSW). Patients with GSWs were more severely injured (mean ISS 17.00 vs. 8.84 [P=0.0014] and ISS≥16 in 53.3% vs. 16.7%) than SW patients. In CT, intrathoracic injuries were found in 49.4% (77/156) and active bleeding in 26.3% (41/156). Emergency surgery was performed in 6.2% (10/161) with postoperative CT imaging. Thirty-day mortality rate was 1.2% (2/161).

Conclusion

Penetrating thoracic trauma often violates intrathoracic structures and nearby compartments. Arterial phase whole-body CT is recommended as multiple injuries and active bleeding are common. CT after emergency surgery is warranted, especially to assess injuries outside the surgical field.

Radiologic findings of thoracic trauma

Introduction

Chest trauma may be blunt or penetrating and the chest is the third most common trauma region. It is a significant cause of mortality. Multidetector computed tomography (MDCT) has been an increasingly used method to evaluate chest trauma because of its high success in detecting tissue and organ injuries. Herein, we aimed to present MDCT findings in patients with blunt and penetrating chest trauma admitted to our department.

Methods

A total of 240 patients admitted to the emergency department of our hospital between April 2012 and July 2013 with a diagnosis of chest trauma who underwent MDCT evaluations were included. Most of the patients were male (83.3%) and victims of a blunt chest trauma. The images were analyzed with respect to the presence of fractures of bony structures, hemothorax, pneumothorax, mediastinal organ injury, and pulmonary and vascular injuries.

Results

MDCT images of the 240 patients yielded a prevalence of 41.7% rib fractures, 11.2% scapular fractures, and 7.5% clavicle fractures. The prevalence of thoracic vertebral fracture was 13.8% and that of sternal fracture was 3.8%. The prevalence of hemothorax, pneumothorax, pneumomediastinum, and subcutaneous emphysema was 34.6%, 62.1%, 9.6%, and 35.4%, respectively. The prevalence of rib, clavicle, and thoracic vertebral fractures and pulmonary contusion was higher in the blunt trauma group, whereas the prevalence of hemothorax, subcutaneous emphysema, diaphragmatic injury, and other vascular lacerations was significantly higher in the penetrating trauma group than in the blunt trauma group (p<0.05).

Conclusion

MDCT images may yield a high prevalence of fracture of bony structures, soft tissue lacerations, and vascular lesions, which should be well understood by radiologists dealing with trauma.

Multidetector CT for Penetrating Torso Trauma: State of the Art

The use of computed tomography (CT) for hemodynamically stable victims of penetrating torso trauma continues to increase but remains less singular to the work-up than in blunt trauma. Research in this area has focused on the incremental benefits of CT within the context of evolving diagnostic algorithms and in conjunction with techniques such as laparoscopy, endoscopy, and angiographic intervention. This review centers on the current state of multidetector CT as a triage tool for penetrating torso trauma and the primacy of trajectory evaluation in diagnosis, while emphasizing diagnostic challenges that have lingered despite tremendous technological advances since CT was first used in this setting 3 decades ago. As treatment strategies have also changed considerably over the years in parallel with advances in CT, current management implications of organ-specific injuries depicted at multidetector CT are also discussed.