Radiographics : a review publication of the Radiological Society of North America, Inc
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The use of metal and pyrolytic carbon radial head implants, capitellar resurfacing, and total elbow arthroplasty has become common in contemporary orthopedic surgery practice. The goal of total elbow arthroplasty is to decrease pain and restore an acceptable range of motion to the elbow joint. Rheumatoid arthritis is the primary indication for total elbow arthroplasty; newer indications include primary or posttraumatic osteoarthritis, fracture nonunion, acute comminuted fractures of the elbow, and postoperative resection of a neoplasm. ⋯ The goals of capitellar resurfacing arthroplasty include prevention of secondary osteoarthritis of the radiocapitellar joint and erosion in patients with radial head arthroplasty. Effective postoperative radiologic assessment of these different types of elbow reconstructions requires an understanding of their basic component design, physiologic purpose, and normal postoperative appearance, as well as the appearance of complications. Radiologists may have little training and experience with these new orthopedic devices.
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The celiac plexus is the largest visceral plexus and is located deep in the retroperitoneum, over the anterolateral surface of the aorta and around the origin of the celiac trunk. It serves as a relay center for nociceptive impulses that originate from the upper abdominal viscera, from the stomach to the proximal transverse colon. Celiac plexus neurolysis, with agents such as ethanol, is an effective means of diminishing pain that arises from these structures. ⋯ Accurate depiction of the retroperitoneal anatomy and the position of the needle tip helps avoid crucial anatomic structures such as the pancreas, aorta, celiac artery, and superior mesenteric artery. Proper patient education, meticulous preprocedure planning, use of optimal multidetector CT techniques, adjunctive CT maneuvers, and postprocedure care are integral to successful celiac plexus neurolysis. Celiac plexus neurolysis does not completely abolish pain; rather, it diminishes pain, helping to reduce opioid requirements and their related side effects and improving survival in patients with upper abdominal malignancy.
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Venous injuries as a result of blunt trauma are rare. Even though current protocols for multidetector computed tomography (CT) of patients with trauma are designed to evaluate primarily the solid organs and arteries, blunt venous injuries may nevertheless be identified, or at least suspected, on the basis of the multidetector CT findings. Venous injuries are associated with high morbidity and mortality rates. ⋯ This article aims to make the radiologist aware of various venous injuries caused by blunt trauma and to provide helpful hints to aid in the identification of venous injuries. Multidetector CT technology, in combination with interactive manipulation of the raw dataset, can be useful in the creation of multiplanar reconstructed images and in the identification of a venous injury caused by blunt trauma. Familiarity with direct and indirect signs of venous injuries, as well as with examples of blunt traumatic venous injuries in the chest, abdomen, and pelvis, will help in the diagnosis of these injuries.
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Cardiac injury due to blunt or penetrating chest trauma is common and is associated with significant morbidity and mortality. Understanding the mechanisms, types, and complications of cardiac injuries and the roles of various imaging modalities in characterizing them is important for appropriate diagnosis and treatment. These injuries have not been well documented at imaging, but there are now fast and accurate methods for evaluating the heart and associated mediastinal structures. ⋯ While many imaging modalities are available, the authors demonstrate the value of multidetector computed tomography (CT) for the initial evaluation of patients with blunt or penetrating chest trauma. With the advent of multidetector CT, imaging of cardiac injury has increased and accurate identification of these rare but potentially lethal injuries has become paramount for improving survival. Selection of the most appropriate modality for evaluation and recognition of the imaging findings in cardiac injuries in the acute trauma setting is important to expedite treatment and improve survival.
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In addition to existing strategies for reducing radiation dose in computed tomographic (CT) examinations, such as the use of automatic exposure control, use of the optimal tube potential also may help improve image quality or reduce radiation dose in pediatric CT examinations. The main benefit of the use of a lower tube potential is that it provides improved contrast enhancement, a characteristic that may compensate for the increase in noise that often occurs at lower tube potentials and that may allow radiation dose to be substantially reduced. ⋯ The power limits of the CT scanner and the desired scanning speed also must be considered. The use of a lower tube potential and the amount by which to reduce radiation dose must be carefully evaluated for each type of examination to achieve an optimal tradeoff between contrast, noise, artifacts, and scanning speed.