Nontraumatic Spinal Cord Compression: MRI Primer for Emergency Department Radiologists.

The occurrence of acute myelopathy in a nontrauma setting constitutes a medical emergency for which spinal MRI is frequently ordered as the first step in the patient's workup. The emergency department radiologist should be familiar with the common differential diagnoses of acute myelopathy and be able to differentiate compressive from noncompressive causes. The degree of spinal cord compression and presence of an intramedullary T2-hyperintense signal suggestive of an acute cord edema are critical findings for subsequent urgent care such as surgical decompression. Importantly, a delay in diagnosis may lead to permanent disability. In the spinal canal, compressive myelopathy can be localized to the epidural, intradural extramedullary, or intramedullary anatomic spaces. Effacement of the epidural fat and the lesion's relation to the thecal sac help to distinguish an epidural lesion from an intradural lesion. Noncompressive myelopathy manifests as an intramedullary T2-hyperintense signal without an underlying mass and has a wide range of vascular, metabolic, inflammatory, infectious, and demyelinating causes with seemingly overlapping imaging appearances. The differential diagnosis can be refined by considering the location of the abnormal signal intensity within the cord, the longitudinal extent of the disease, and the clinical history and laboratory findings. Use of a compartmental spinal MRI approach in patients with suspected nontraumatic spinal cord injury helps to localize the abnormality to an epidural, intradural extramedullary, or intramedullary space, and when combined with clinical and laboratory findings, aids in refining the diagnosis and determining the appropriate surgical or nonsurgical management.Online supplemental material is available for this article.©RSNA, 2019.

Multidetector CT of Laryngeal Injuries: Principles of Injury Recognition.

Blunt laryngeal trauma is associated with high morbidity and mortality. However, owing to their relatively rare occurrence, laryngeal injuries may be missed or underdiagnosed. Even subtle abnormalities at multidetector CT may correspond to significant functional abnormalities. It is important to understand normal CT laryngeal anatomy and develop a systematic review of the cervical soft tissues and laryngeal skeleton in patients who undergo screening CT cervical spine or other neck examinations in the setting of trauma, such as CT angiography. Multidetector CT findings of the normal larynx are reviewed, and blunt laryngeal injuries including soft-tissue edema, hematoma, mucosal lacerations, cartilage fracture, cricoarytenoid dislocation, and vocal fold paralysis are presented. The radiologist plays an important role in diagnosis and may be the first to identify laryngeal injuries that are not evident at physical examination. This article reviews normal laryngeal anatomy, presents various blunt laryngeal injuries at multidetector CT with case examples, discusses the role of multidetector CT in acute management, and describes pitfalls of diagnosis. ©RSNA, 2019.

CT for Treatment Selection in Acute Ischemic Stroke: A Code Stroke Primer.

CT is the primary imaging modality used for selecting appropriate treatment in patients with acute stroke. Awareness of the typical findings, pearls, and pitfalls of CT image interpretation is therefore critical for radiologists, stroke neurologists, and emergency department providers to make accurate and timely decisions regarding both (a) immediate treatment with intravenous tissue plasminogen activator up to 4.5 hours after a stroke at primary stroke centers and (b) transfer of patients with large-vessel occlusion (LVO) at CT angiography to comprehensive stroke centers for endovascular thrombectomy (EVT) up to 24 hours after a stroke. Since the DAWN and DEFUSE 3 trials demonstrated the efficacy of EVT up to 24 hours after last seen well, CT angiography has become the operational standard for rapid accurate identification of intracranial LVO. A systematic approach to CT angiographic image interpretation is necessary and useful for rapid triage, and understanding common stroke syndromes can help speed vessel evaluation. Moreover, when diffusion-weighted MRI is unavailable, multiphase CT angiography of collateral vessels and source-image assessment or perfusion CT can be used to help estimate core infarct volume. Both have the potential to allow distinction of patients likely to benefit from EVT from those unlikely to benefit. This article reviews CT-based workup of ischemic stroke for making tPA and EVT treatment decisions and focuses on practical skills, interpretation challenges, mimics, and pitfalls.©RSNA, 2019.

Injuries to the Rigid Spine: What the Spine Surgeon Wants to Know.

The biomechanical stability of the spine is altered in patients with a rigid spine, rendering it vulnerable to fracture even from relatively minor impact. The rigid spine entities are ankylosing spondylitis (AS), diffuse idiopathic skeletal hyperostosis, degenerative spondylosis, and a surgically fused spine. The most common mechanism of injury resulting in fracture is hyperextension, which often leads to unstable injury in patients with a rigid spine per the recent AOSpine classification system. Due to the increased risk of spinal fractures in this population, performing a spine CT is the first step when a patient with a rigid spine presents with new back pain or suspected spinal trauma. In addition, there should be a low threshold for performing a non-contrast-enhanced spine MRI in patients with a rigid spine, especially those with AS who may have an occult fracture, epidural hematoma, or spinal cord injury. Unfortunately, owing to insufficient imaging and an unfamiliarity with fracture patterns in the setting of a rigid spine, fracture diagnosis is often delayed, leading to significant morbidity and even death. The radiologist's role is to recognize the imaging features of a rigid spine, identify any fractures at CT and MRI, and fully characterize the extent of injury. Reasons for surgical intervention include neurologic deficit or concern for deterioration, an unstable fracture, or the presence of an epidural hematoma. By understanding the imaging features of various rigid spine conditions and vigilantly examining images for occult fractures, the radiologist can avoid a missed or delayed diagnosis of an injured rigid spine. ©RSNA, 2019.

Utility of MRI for cervical spine clearance in blunt trauma patients after a negative CT.

PURPOSE: To determine the utility of cervical spine MRI in blunt trauma evaluation for instability after a negative non-contrast cervical spine CT. METHODS: A review of medical records identified all adult patients with blunt trauma who underwent CT cervical spine followed by MRI within 48 h over a 33-month period. Utility of subsequent MRI was assessed in terms of findings and impact on outcome. RESULTS: A total of 1,271 patients with blunt cervical spine trauma underwent both cervical spine CT and MRI within 48 h; 1,080 patients were included in the study analysis. Sixty-six percent of patients with a CT cervical spine study had a negative study. Of these, the subsequent cervical spine MRI had positive findings in 20.9%; 92.6% had stable ligamentous or osseous injuries, 6.0% had unstable injuries and 1.3% had potentially unstable injuries. For unstable injury, the NPV for CT was 98.5%. In all 712 patients undergoing both CT and MRI, only 1.5% had unstable injuries, and only 0.42% had significant change in management. CONCLUSIONS: MRI for blunt trauma evaluation remains not infrequent at our institution. MRI may have utility only in certain patients with persistent abnormal neurological examination. KEY POINTS: • MRI has limited utility after negative cervical CT in blunt trauma. • MRI is frequently positive for non-specific soft-tissue injury. • Unstable injury missed on CT is infrequent.

Core curriculum illustration: invasive fungal sinusitis.

This is the 27th installment of a series that will highlight one case per publication issue from the bank of cases available online as part of the American Society of Emergency Radiology (ASER) educational resources. Our goal is to generate more interest in and use of our online materials. To view more cases online, please visit the ASER Core Curriculum and Recommendations for Study online at http://www.erad.org/?page=CCIP_TOC .

Imaging evaluation of adult spinal injuries: emphasis on multidetector CT in cervical spine trauma.

As computed tomography (CT) technology has evolved, multidetector CT has become an integral part of the initial assessment of many injured patients, and the spine is easily included in the total body screening performed in patients with severe blunt polytrauma. Despite all the advantages of multidetector CT, clearing the spine in which injury is suspected continues to be a daily challenge in clinical practice. The purpose of this review is to present the evidence and the controversies surrounding the practice of imaging in patients suspected of having spine injury. The discussion is centered on the increasing reliance on multidetector CT in the work-up of these patients but also considers the important contributions of clinical trials to select patient for appropriate imaging on the basis of risk and probability of injury. Available protocols, injury classification systems, and issues awaiting future research are addressed.

Role of multidetector computed tomography in the assessment of cervical spine trauma.

Clearing the cervical spine has relied on individual and center-based experience. Not long ago, the screening modality of choice was radiography. The evidence now clearly supports multidetector computed tomography as the modality of choice for evaluating cervical spine trauma because of its higher accuracy and efficiency compared to radiography. Furthermore, clinical criteria have been validated to assess for cervical spine injuries and determine the need for imaging evaluation based on patient risk. Once imaging is deemed necessary to exclude cervical spine injury based on clinical predictors, multidetector computed tomography becomes the accepted modality of choice, providing accurate and rapid assessment and improving the understanding of injury patterns and stability determinants.

Head and Neck Injuries: Special Considerations in the Elderly Patient.

Traumatic injuries to the head and neck are common in the elderly, which is a rapidly growing sector of the American population. Most injuries result from low-energy falls and therefore might be at risk for delayed presentation and undertriage. Imaging, particularly with computed tomography, plays a vital role in the evaluation of traumatic head and neck injuries in geriatric patients. A thorough understanding of the differing patterns of trauma in the elderly patient and the factors that are associated with poorer outcomes is essential.

Imaging of blunt cerebrovascular injuries.

Arterial dissection, pseudoaneurysm, arteriovenous fistula, arterial laceration and occlusion are uncommon complications of blunt trauma. Angiography has been considered the primary method of evaluation to assess for vascular injuries but, due to the low frequency of these lesions, its screening role has been challenged. Non-invasive imaging, particularly CT angiography (CTA), offers definitive advantages and has emerged as a promising diagnostic screening method. Angiography is shifting to a rather therapeutic role and the endovascular management of these lesions is briefly discussed.

Spectrum of imaging findings in hyperextension injuries of the neck.

Nonphysiologic hyperextension and lateral forces acting on the cervical spine and soft-tissue structures of the neck can result in a wide spectrum of injury patterns. Multiple factors (eg, patient age; the underlying morphologic features of the cervical spine; the magnitude, vector, and maximal focus of the force) all influence the observed patterns and the severity of injury. A review of the 5-year trauma database in two trauma centers revealed various injury patterns that were frequently recognized in patients with clinical evidence or historical documentation of a predominant hyperextension mechanism. Injuries included anterior arch avulsion and posterior arch compression fractures of the atlas, odontoid fractures, traumatic spondylolisthesis and teardrop fracture of C2, laminar and articular pillar fractures, and hyperextension dislocation injuries. More severe injuries were observed in patients with underlying predisposing conditions (eg, degenerative spondylosis, ankylosing spondylitis, diffuse idiopathic skeletal hyperostosis). Knowledge of the involved biomechanical factors provides a framework for understanding these injury patterns. Diagnostic imaging, especially computed tomography and magnetic resonance imaging, plays a fundamental role in the assessment of patients with suspected cervical injury. Furthermore, cross-sectional imaging facilitates the recognition of accompanying injuries to the face, the head, and the vascular structures of the neck.

Vascular injuries of the neck and thoracic inlet: helical CT-angiographic correlation.

Imaging evaluation of patients suspected to have arterial injuries of the neck has traditionally been performed by using conventional angiography as an alternative to surgical exploration. However, there has been recent interest in and growing experience with use of noninvasive imaging techniques for the assessment of vascular injuries. Contrast material-enhanced helical computed tomographic (CT) angiography is increasingly being used to evaluate trauma patients in stable condition who are at risk for vascular injuries. It allows characterization of traumatic vascular lesions in the neck such as partial or complete occlusion, pseudoaneurysm, intimal flap, dissection, and arteriovenous fistula. In the same setting, CT angiography provides valuable additional information about the cervical soft tissues, aerodigestive tract, spinal canal, and spinal cord. In cases of penetrating gunshot injuries, the trajectory of the bullet and the locations of fragments can be assessed. CT angiography may be limited by artifacts from metallic fragments and occasionally by abundant soft-tissue air or streak artifacts in the shoulders. In such cases, conventional angiography is necessary for optimal assessment of vascular injuries. CT angiography can be used as a noninvasive alternative to conventional angiography in patients suspected to have vascular injuries but without initial indications for surgical treatment.

Helical CT for the Evaluation of Cervical Vertebral Injuries.

The imaging evaluation of the cervical vertebral column in patients subjected to nontrivial trauma has been a subject of major debate in trauma care. A variety of protocols have been proposed that comprise different combinations of radiographs with or without computed tomography (CT) and magnetic resonance imaging in selected cases. In our institution, helical computed tomography (HCT) of the cervical region has been used in the initial assessment of trauma patients either as a screening modality or as an adjunct to radiography. Our results support the use of HCT because it has improved fracture detection and provided better depiction of the extent of injury. More importantly, we have found that significant fractures can be missed when exclusively relying on radiography. In addition, the time for clearance of the cervical column and the disposition time of patients from the trauma area have been reduced while improving the utilization of CT.

Medicina centrada en el paciente: los retos que afronta la radiología / Patient-centered medicine: challenges for radiology

No disponible

Trauma to the ankylotic spine: imaging spectrum of vertebral and soft tissue injuries.

The objectives of the study were to review the clinical entities that can cause ankylosis of the spine and to illustrate the spectrum of traumatic injury patterns. Ankylosing spondylitis, diffuse idiopathic systemic hyperostosis, degenerative spondyloarthropathy, and spinal canal stenosis can render the spine susceptible to trivial trauma. Multidetector computed tomography and magnetic resonance imaging can accurately diagnose vertebral and soft tissue traumatic injury patterns in this patient population.

Helical and multislice CTA following penetrating trauma to the subclavian and axillary arteries (pictorial essay).

Penetrating injuries with resultant trauma to the subclavian and axillary arteries have traditionally been evaluated with direct contrast angiography. Physical examination has a low sensitivity for detection of vascular injuries in stable patients and surgical exploration is challenging. With advancements in CT technology, a less invasive and more rapid approach in evaluating arterial injury is now being utilized in many trauma centers. This article will depict the CT angiographic signs of subclavian and axillary artery injuries.

Arteriovenous fistula following pacemaker lead removal: CT diagnosis.

Arteriovenous fistula formation is a very rare complication of pacemaker lead extraction. Rapid diagnosis is essential due to the life-threatening nature of this complication. CT angiography provides a noninvasive and quick method for assessment.