Radiologic appearance of chronic parapharyngeal Teflon granuloma.

Although Teflon has been used for almost 5 decades to provide tissue augmentation in various surgical indications, including head and neck surgery, its use has significantly declined in the last 2 decades, primarily because of its implication in granuloma formation. Teflon granulomas have been shown to cause false positives on positron emission tomography imaging and have been reported to have a characteristic magnetic resonance imaging (MRI) appearance. We report a patient with a large chronic Teflon granuloma of the parapharyngeal space that caused significant bony erosion of the atlas vertebra.

Glossopharyngeal schwannoma of the suprahyoid carotid space: case report and discussion of the relationship to the carotid artery.

Background: The distinction between lesions of the deep parotid space and those of the carotid space has been greatly facilitated by cross-sectional imaging, particularly magnetic resonance imaging (MRI), due to 1) good assessment of parapharyngeal fat displacement, and 2) reliable and consistent identification of the carotid artery. While masticator space masses consistently displace the carotid artery posteriorly, it is generally assumed that carotid space masses, particularly schwannomas, displace the carotid artery anteriorly. We report on a patient with a rare glossopharyngeal schwannoma of the carotid space that caused posterior displacement of the carotid artery.

Magnetic resonance imaging of the orbit.

Magnetic resonance imaging (MRI) employs the nuclear resonance phenomenon to produce images of living tissues. Unlike computed tomography (CT), which relies solely on differences in the propensity of tissues to absorb X-rays to produce various contrasts, MRI offers a wide variety of pulse sequences, each of which exploits differences in the magnetic properties of protons in living tissue to produce contrast resolution. When optimal protocols are used, MRI contrast resolution in the orbital soft tissues is superior to that provided by any other imaging modality.

Culture-Negative intracerebral abscesses in children and adolescents from Streptococcus anginosus group infection: a case series.

We report the use of 16S ribosomal RNA gene amplification and sequencing to diagnose culture-negative intracerebral abscesses in younger patients. These 3 cases demonstrate the optimal application of gene sequencing from direct specimens for patients with negative culture results compromised by antibacterial therapy but histories highly suggestive of acute bacterial infection.

Interventional neuroradiology for the ophthalmologist.

The past two decades have witnessed major advances in diagnosing vascular conditions that affect blood supply and hemorrhagic risk to the brain and the eye. Technological improvements have resulted in the ability to better radiologically image the cerebrovascular system and to deliver pharmacological and embolic agents that have high specificity. Neuroradiological interventional therapy has become the preferred option in managing many conditions that were previously treated by standard neurosurgical procedures.

Orbital rhabdomyosarcoma and simulating lesions.

The appropriate diagnosis and treatment of orbital rhabdomyosarcoma requires close cooperation and communication between the radiologist, the ophthalmologist, and the medical and radiation oncologists. The clinical presentation, imaging characteristics, and staging of orbital rhabdomyosarcoma are discussed. A discussion of several important simulating lesions and their distinguishing characteristics follows.