Radiographics : a review publication of the Radiological Society of North America, Inc
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Computed tomography (CT) and ultrasonography (US) are ideally suited for demonstrating urachal remnant diseases. A patent urachus is demonstrated at longitudinal US and occasionally at CT as a tubular connection between the anterosuperior aspect of the bladder and the umbilicus. An umbilical-urachal sinus manifests at US as a thickened tubular structure along the midline below the umbilicus. ⋯ Percutaneous needle biopsy or fluid aspiration is usually needed for diagnosis and therapeutic planning. Nevertheless, CT and US can help identify most disease entities originating from the urachal remnant in the anterior abdominal wall. Understanding the anatomy and the imaging features of urachal remnant diseases is essential for correct diagnosis and proper management.
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Bronchial anatomy is adequately demonstrated with the appropriate spiral computed tomographic technique on cross-sectional images, multiplanar reconstruction images, and three-dimensional reconstruction images. Contrary to the numerous variations of lobar or segmental bronchial subdivisions, abnormal bronchi originating from the trachea or main bronchi are rare. Major bronchial abnormalities include accessory cardiac bronchus (ACB) and "tracheal" bronchus. ⋯ Minor bronchial abnormalities include variants of tracheal bronchus, displaced segmental bronchi, and bronchial agenesis. The main embryogenic hypotheses for congenital bronchial abnormalities are the reduction, migration, and selection theories. Knowledge and understanding of congenital bronchial abnormalities may have important implications for diagnosis, bronchoscopy, surgery, brachytherapy, and intubation.
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Detection of bowel and mesenteric injury can be challenging in patients after blunt abdominal trauma. Early diagnosis and treatment are critical to decrease patient morbidity and mortality. Computed tomography (CT) has become the primary modality for the imaging of these patients. ⋯ Bowel-wall thickening, free fluid, and mesenteric infiltration may be seen with this type of injury and partial thickness injuries. The authors present and discuss the range of CT findings seen with bowel and mesenteric injuries. Examples of observation and interpretation errors are also provided to highlight pitfalls encountered in the evaluation of abdominopelvic CT scans in patients after blunt trauma.
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Comparative Study
Radiologic spectrum of craniocervical distraction injuries.
Injuries to the atlanto-occipital region, which range from complete atlanto-occipital or atlantoaxial dislocation to nondisplaced occipital condyle avulsion fractures, are usually of critical clinical importance. At initial cross-table lateral radiography, measurement of the basion-dens and basion-posterior axial line intervals and comparison with normal measurements may help detect injury. Computed tomography (CT) with sagittal and coronal reformatted images permits optimal detection and evaluation of fracture and luxation. ⋯ All imaging studies should be conducted with special attention to bone integrity and the possibility of soft-tissue injury. Atlanto-occipital injuries are now recognized as potentially survivable, although commonly with substantial morbidity. Swift diagnosis by the trauma radiologist is crucial for ensuring prompt, effective treatment and preventing delayed neurologic deficits in patients who survive such injuries.
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Bone marrow contusions are frequently identified at magnetic resonance imaging after an injury to the musculoskeletal system. These osseous injuries may result from a direct blow to the bone, from compressive forces of adjacent bones impacting one another, or from traction forces that occur during an avulsion injury. The distribution of bone marrow edema is like a footprint left behind at injury, providing valuable clues to the associated soft-tissue injuries. ⋯ The clip injury results in a prominent area of edema involving the lateral femoral condyle and a smaller area of edema involving the medial femoral condyle. Finally, lateral patellar dislocation results in edema involving the inferomedial patella and anterior aspect of the lateral femoral condyle. In many instances, the mechanism of injury can be determined by studying the distribution of bone marrow edema, which then enables one to predict with accuracy the specific soft-tissue abnormalities that are likely to be present.