Role of Multidetector Row Computed Tomography in the Management of Mandible Traumatic Lesions

Radiological investigation of acute mandibular injury

This article focuses on the different imaging modalities used to evaluate acute mandibular fractures and explores important concepts relating to their diagnosis, investigation, and treatment. Significant focus will be given to exploring general management principles, considerations regarding first-line imaging, and recent technological advancement. Computed tomography (CT) is the preferred method when attempting to identify acute mandibular fractures, particularly in trauma patients, and has very high specificity and sensitivity. Multidetector CT now represents the standard of care, enabling fast scan times, reduced artifact, accurate reconstructed views, and three-dimensional (3D) reconstructions. Cone-beam CT is a newer advanced imaging modality that is increasingly being used worldwide, particularly in the ambulatory and intraoperative setting. It produces high-resolution images with submillimeter isotropic voxels, 3D and multiplanar reconstruction, and low radiation dose, however is less widely available and more expensive. Ultrasound is a valuable method in identifying a fracture in unstable patients, but is limited in its ability to detect nondisplaced fractures. Magnetic resonance imaging is useful in determining the presence of soft-tissue injury. CT angiography is invaluable in the assessment of potential vascular injury in condylar fracture dislocations.

Postoperative CT of the Mandible Following Trauma: Review of Normal Appearances and Common Complications

RATIONALE AND OBJECTIVES

Surgeons aim to restore occlusion and jaw function to baseline status for patients with mandibular fractures using either closed treatment or reduction and fixation.

MATERIALS AND METHODS

Occlusion is defined as the relationship between the maxillary and mandibular teeth as they approach each other.

RESULTS

Radiologists should be familiar with the goals of repair to help identify which treatment is adequate as well as to diagnose potential complications. Some of the more common complications encountered are infection, nonunion or malunion, and malocclusion.

CONCLUSION

We provide a comprehensive review of both the desired and untoward CT findings after surgical repair of traumatic mandibular injuries.

Traumatic fractures in adults: missed diagnosis on plain radiographs in the Emergency Department

Radiography remains the imaging standard for fracture detection after trauma. The radiographic diagnosis of most fractures and dislocations poses little difficulty to radiologists: however, occasionally these injuries are quite subtle or even impossible to detect on radiographs. Missed diagnoses of fracture potentially have important consequences for patients, clinicians, and radiologists. Radiologists play a pivot role in the diagnostic assessment of the trauma patients: emergency radiologists who are more practiced at seeking out and discerning traumatic fractures can provide an invaluable service to their clinical colleagues by ensuring that patients do not endure delayed diagnoses. This is a narrative review article aims to highlight the spectrum of fractures in adults potentially missed on plain radiographs, the causes of error in diagnosis of fractures in the emergency setting and the key elements to reduce misdiagnosis of fractures. (www.actabiomedica.it)

Scapular fractures: a common diagnostic pitfall

Scapular fractures are one of the most difficult fractures to diagnose on radiographs. Detection can be challenging because of the obscuration by the overlying structures or incomplete imaging due to difficult patient collaboration. Familiarity with imaging characteristics of these abnormalities will allow radiologists to better diagnose and characterize scapular fractures. Three-dimensional computed tomographic scans are considered the gold standard for scapular diagnoses. Treatment strategies differ depending on the type of scapular fractures, but the site and degree of displacement will determine whether surgical intervention should be considered. Complications can occur in fractures that are undiagnosed or improperly evaluated. The purpose of this article is to describe imaging features of traumatic scapular injury, and discuss the role of diagnostic imaging in clinical decision making after shoulder trauma. (www.actabiomedica.it)

Multidetector CT of Mandibular Fractures, Reductions, and Complications: A Clinically Relevant Primer for the Radiologist

After the nasal bones, the mandible is the second most common site of facial fractures, and mandibular fractures frequently require open reduction. In the trauma injury setting, multidetector computed tomography (CT) has become the cornerstone imaging modality for determining the most appropriate treatment management, fixation method, and surgical approach. Multidetector CT is also used to assess the adequacy of the reduction and evaluate potential complications in the postoperative period. For successful restoration of the mandible's form and function, as well as management of posttraumatic and postoperative complications, reconstructive surgeons are required to have a detailed understanding of mandibular biomechanics, occlusion, and anatomy. To provide added value in the diagnosis, treatment planning, and follow-up of mandibular fractures, radiologists should be aware of these concepts. Knowledge of the techniques commonly used to achieve occlusal and anatomic reduction and of the rationale behind the range of available treatment options for different injury patterns-from isolated and nondisplaced fractures to multisite and comminuted fractures-also is essential. This article focuses on the use of multidetector CT for pre- and postoperative evaluation of mandibular fractures and outlines fundamental concepts of diagnosis and management-beginning with an explanation of common fracture patterns and their biomechanical underpinnings, and followed by a review of the common postoperative appearances of these fractures after semirigid and rigid fixation procedures. Specific considerations regarding fractures in different regions of the tooth-bearing and non-tooth-bearing mandible and the unique issues pertaining to the edentulous atrophic mandible are reviewed, and key features that distinguish major from minor complications are described. (©)RSNA, 2016.

A comparable study of the diagnostic performance of orbital ultrasonography and CBCT in patients with suspected orbital floor fractures

OBJECTIVES:

To compare the diagnostic performance of ultrasonography and CBCT against CT in detecting orbital floor fractures.

METHODS:

A total of 120 orbits with clinical suspicion of isolated orbital floor fractures underwent multislice CT scanning with coronal reconstruction; orbital ultrasonography using a standard machine equipped with a 7- to 10-MHz linear transducer; and CBCT. Patients with severe head and face injuries were not included. The diagnostic performance of ultrasonography and CBCT was reported assuming conventional CT as the imaging method of choice.

RESULTS:

According to CT findings, fractures of the floor were present in 39 orbits. The sensitivity, specificity, positive-predictive value and negative-predictive value of ultrasonography in detecting orbital floor fractures were 87.2%, 100%, 100% and 94.2%, respectively. The corresponding values for CBCT were 97.4%, 97.5%, 95.0%, and 98.8%, respectively. Areas under the receiver operator characteristics curves of orbital floor fracture detection were 0.94 for ultrasonography and 0.98 for CBCT.

CONCLUSIONS:

When conventional CT cannot be performed in patients with clinically suspected orbital floor fracture and no severe or complex head and face injuries, CBCT could be used in detecting fractures as a reliable surrogate. Because of a lower sensitivity of ultrasonography, however, its use is limited in this regard.

Orbital fractures: role of imaging

The orbit may be injured directly or indirectly. Blunt and penetrating trauma occurs with equal frequency. Soft tissue swelling often obscures direct clinical evaluation of the globe, limits ocular motion, and may limit clinical assessment of vision. Plain film radiographs of the orbits and sinuses are rarely used for diagnosis in orbital trauma. Computed tomography is considered the imaging modality of choice in this circumstance, as it is deemed to be the most accurate method in detecting fractures. The protocol is based on obtaining thin-section axial scans and multiplanar reformatted images, both are useful tools to guide treatment. Orbital fractures are not considered an ophthalmologic emergency unless there is visual impairment or globe injury. Surgical repair is indicated for patients who have persistent diplopia or cosmetic concerns (enophthalmos) and generaly is not performed until swelling subsides 7-10 days after injury.