Classic signs in head and neck imaging.

Radiologists have long relied upon the use of metaphoric imaging signs to attribute meaning to disease or anatomy-specific imaging patterns encountered in clinical imaging. Teachers of radiology often employ the use of such signs to help learners rapidly identify the typical appearance of various pathologies. Head and neck (H&N) imaging is no exception, and as a specialty that deals with uncommon pathologies and complex anatomy, learners and practising radiologists alike may benefit from this simplistic, pattern-based approach. In this review, we present a compendium of classic imaging signs of H&N lesions, including signs related to traumatic, infectious, neoplastic, congenital, and inflammatory aetiologies found throughout the spectrum of H&N sites (temporal bones, orbits, paranasal sinuses, larynx, salivary glands, and neck soft tissues). Additionally, we identify potential pitfalls and detail critical clinical ramifications related to the rapid and accurate diagnosis of these pathologies.

Management of sword-swallower injuries.

OBJECTIVE: To report an unusual case of hypopharyngeal perforation in a sword-swallower, with emphasis on management options. METHOD: Case report and review of the English language literature concerning sword-swallowing injuries to the hypopharynx and oesophagus. RESULTS: A 29-year-old male sword-swallower suffered hypopharyngeal perforation during a performance. The patient received conservative management, with intensive care unit admission, infectious disease consultation, intravenous antibiotics, discontinuation of oral intake and close observation. He progressed well, resumed oral intake on hospital day six, and was discharged home on hospital day eight. CONCLUSION: Sword-swallowing is an unusual vocation which may lead to potentially devastating injuries. This case report and review of the literature illustrates the management options for such hypopharyngeal and oesophageal injuries.

Intra-osseous meningioma of the orbit: an unusual presentation (2007: 5b).

Primary calvarial or intra-osseous meningiomas are uncommon lesions often confused preoperatively with other primary or secondary bone tumors of the skull. We present details of a patient with a primary calvarial meningioma involving the frontal, zygomatic, sphenoid and temporal bones that was radiographically diagnosed as fibrous dysplasia and initially treated conservatively for many years. Progressive vision loss and significant proptosis, with difficulty of eye closure, prompted surgical removal with cranioplasty and a 3D reconstructed prosthetic flap. Histological examination revealed intra-osseous meningioma. The clinical and radiological findings of intra-osseous meningiomas are discussed, together with a review of the literature.

Neural control of tongue movement with respect to respiration and swallowing.

The tongue must move with remarkable speed and precision between multiple orofacial motor behaviors that are executed virtually simultaneously. Our present understanding of these highly integrated relationships has been limited by their complexity. Recent research indicates that the tongue s contribution to complex orofacial movements is much greater than previously thought. The purpose of this paper is to review the neural control of tongue movement and relate it to complex orofacial behaviors. Particular attention will be given to the interaction of tongue movement with respiration and swallowing, because the morbidity and mortality associated with these relationships make this a primary focus of many current investigations. This review will begin with a discussion of peripheral tongue muscle and nerve physiology that will include new data on tongue contractile properties. Other relevant peripheral oral cavity and oropharyngeal neurophysiology will also be discussed. Much of the review will focus on brainstem control of tongue movement and modulation by neurons that control swallowing and respiration, because it is in the brainstem that orofacial motor behaviors sort themselves out from their common peripheral structures. There is abundant evidence indicating that the neural control of protrusive tongue movement by motoneurons in the ventral hypoglossal nucleus is modulated by respiratory neurons that control inspiratory drive. Yet, little is known of hypoglossal motoneuron modulation by neurons controlling swallowing or other complex movements. There is evidence, however, suggesting that functional segregation of respiration and swallowing within the brainstem is reflected in somatotopy within the hypoglossal nucleus. Also, subtle changes in the neural control of tongue movement may signal the transition between respiration and swallowing. The final section of this review will focus on the cortical integration of tongue movement with complex orofacial movements. This section will conclude with a discussion of the functional and clinical significance of cortical control with respect to recent advances in our understanding of the peripheral and brainstem physiology of tongue movement.

Parameters of radiologic care: An official report of the American Academy of Oral and Maxillofacial Radiology.

The American Academy of Oral and Maxillofacial Radiology developed these Parameters of Care to provide national guidelines for the use of radiographs prescribed for the diagnosis of disease, treatment planning, and follow-up care of patients with abnormalities of the oral and maxillofacial region. The Parameters cover radiographic techniques, imaging of the temporomandibular joint, imaging of diseases of the jaws, and imaging of dental implant sites.

Lateralization of cortical function in swallowing: a functional MR imaging study.

BACKGROUND AND PURPOSE: While functional MR imaging and other techniques have contributed to our knowledge of functional brain localization, these methods have not been extensively applied to the complex and incompletely understood task of swallowing. We used functional MR imaging to investigate motor cortex activity during swallowing in healthy human adults. METHODS: Eight subjects were imaged on a 1.5-T MR system using blood oxygen level-dependent contrast mechanisms. Subjects performed three swallowing tasks and a finger-tapping task. Areas of activation in the cortex and subcortical areas were tabulated, and a laterality index, defined as LI = [sigmas left - sigmas right]/[sigmas left + sigmas right] x 100, was computed for the three tasks. RESULTS: Activation was observed in the primary motor and sensory cortices, motor processing and association areas, and subcortical sites. This activity was dominant for one hemisphere with left hemispheric dominance more prevalent among the subjects. Right hemispheric dominance, however, showed stronger lateralization than the left hemisphere. CONCLUSION: Our data indicate that specific sites in the motor cortex and other cortical and subcortical areas are activated with swallowing tasks and that hemispheric dominance is a feature of swallowing under these conditions. In addition, we demonstrate the utility of functional MR imaging in the study of the cortical representation of swallowing and suggest a role for functional MR imaging in the diagnosis of dysphagia of cerebral origin.

Dosimetry and cost of imaging osseointegrated implants with film-based and computed tomography.

Thermoluminescent dosimeters were used to measure radiation doses at craniofacial sites in a tissue-equivalent phantom during film-based multidirectional tomography with the Tomax Ultrascan (Incubation Industries, Ivyland, Pa.) and during computed tomography with the Elscint Excel 2400 (Elscint Corp., Tel Aviv, Israel). Mean absorbed doses for presurgical mandibular and maxillary canine and molar implant assessments were converted to equivalent doses, which were then multiplied by published weighting factors and summed to give effective doses. The computed tomography device consistently delivered higher doses than the Tomax Ultrascan to all anatomic locations; the differences were most pronounced when only one or two implant sites were evaluated. The reasons for the dose disparities are considered both anatomically and procedurally. A survey of examination cost revealed film-based multidirectional tomography to be less expensive than computed tomography.

Postextraction osteomyelitis in a bone marrow transplant recipient.

This report describes a case of mandibular osteomyelitis after a dental extraction in a patient who subsequently underwent bone marrow transplantation (BMT) for lymphoblastic lymphoma. Surgical guidelines consistent with National Cancer Institute recommendations were followed for the extraction, which was performed before initiation of the myelosuppressive conditioning regimen. However, moderate tenderness developed at the extraction site beginning 10 days after marrow infusion. On day 26 the patient became febrile and blood culture-positive for Staphylococcus epidermidis. Radiographs exposed on day 28 demonstrated changes consistent with low-grade osteomyelitis, including diffuse loss of lamina dura and an irregular osseous rarefaction extending 1 cm posterior to the extraction site. Although the indwelling Hickman catheter was the presumed source for bacteremia, clinical and radiographic data led to consideration of mandibular osteomyelitis as an alternative cause. Characteristics of this infection in BMT recipients are reviewed. Recommendations for dental extractions and prophylactic antibiotic regimens for catheterized BMT recipients are also discussed. Although mandibular osteomyelitic lesions are not common in profoundly immunosuppressed BMT recipients, prompt recognition and treatment are essential when the disease occurs.